and cluster subgraphs, respectively.
This field indicates which graph component uses the attribute.
<HR ALIGN=CENTER WIDTH="70%" SIZE=3>
+<TABLE ALIGN=CENTER>
+<TR><TH>Name</TH><TH><A HREF=#h:uses>Used By</A></TH><TH>Type</TH><TH>Default</TH><TH>Minimum</TH><TH>Notes</TH></TR>
+ <TR><TD><A NAME=a:arrowhead HREF=#d:arrowhead>arrowhead</A>
+</TD><TD>E</TD><TD><A HREF=#k:arrowType>arrowType</A>
+</TD><TD ALIGN="CENTER">normal</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:arrowsize HREF=#d:arrowsize>arrowsize</A>
+</TD><TD>E</TD><TD>double</TD><TD ALIGN="CENTER">1.0</TD><TD>0.0</TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:arrowtail HREF=#d:arrowtail>arrowtail</A>
+</TD><TD>E</TD><TD><A HREF=#k:arrowType>arrowType</A>
+</TD><TD ALIGN="CENTER">normal</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:bb HREF=#d:bb>bb</A>
+</TD><TD>G</TD><TD><A HREF=#k:rect>rect</A>
+</TD><TD ALIGN="CENTER"></TD><TD></TD><TD>write only</TD> </TR>
+ <TR><TD><A NAME=a:bgcolor HREF=#d:bgcolor>bgcolor</A>
+</TD><TD>GC</TD><TD><A HREF=#k:color>color</A>
+</TD><TD ALIGN="CENTER"><none></TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:center HREF=#d:center>center</A>
+</TD><TD>G</TD><TD><A HREF=#k:bool>bool</A>
+</TD><TD ALIGN="CENTER">false</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:charset HREF=#d:charset>charset</A>
+</TD><TD>G</TD><TD>string</TD><TD ALIGN="CENTER">"UTF-8"</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:clusterrank HREF=#d:clusterrank>clusterrank</A>
+</TD><TD>G</TD><TD><A HREF=#k:clusterMode>clusterMode</A>
+</TD><TD ALIGN="CENTER">local</TD><TD></TD><TD>dot only</TD> </TR>
+ <TR><TD><A NAME=a:color HREF=#d:color>color</A>
+</TD><TD>ENC</TD><TD><A HREF=#k:color>color</A>
+<BR><A HREF=#k:colorList>colorList</A>
+</TD><TD ALIGN="CENTER">black</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:colorscheme HREF=#d:colorscheme>colorscheme</A>
+</TD><TD>ENCG</TD><TD>string</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:comment HREF=#d:comment>comment</A>
+</TD><TD>ENG</TD><TD>string</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:compound HREF=#d:compound>compound</A>
+</TD><TD>G</TD><TD><A HREF=#k:bool>bool</A>
+</TD><TD ALIGN="CENTER">false</TD><TD></TD><TD>dot only</TD> </TR>
+ <TR><TD><A NAME=a:concentrate HREF=#d:concentrate>concentrate</A>
+</TD><TD>G</TD><TD><A HREF=#k:bool>bool</A>
+</TD><TD ALIGN="CENTER">false</TD><TD></TD><TD>dot only</TD> </TR>
+ <TR><TD><A NAME=a:constraint HREF=#d:constraint>constraint</A>
+</TD><TD>E</TD><TD><A HREF=#k:bool>bool</A>
+</TD><TD ALIGN="CENTER">true</TD><TD></TD><TD>dot only</TD> </TR>
+ <TR><TD><A NAME=a:Damping HREF=#d:Damping>Damping</A>
+</TD><TD>G</TD><TD>double</TD><TD ALIGN="CENTER">0.99</TD><TD>0.0</TD><TD>neato only</TD> </TR>
+ <TR><TD><A NAME=a:decorate HREF=#d:decorate>decorate</A>
+</TD><TD>E</TD><TD><A HREF=#k:bool>bool</A>
+</TD><TD ALIGN="CENTER">false</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:defaultdist HREF=#d:defaultdist>defaultdist</A>
+</TD><TD>G</TD><TD>double</TD><TD ALIGN="CENTER">1+(avg. len)*sqrt(|V|)</TD><TD>epsilon</TD><TD>neato only</TD> </TR>
+ <TR><TD><A NAME=a:dim HREF=#d:dim>dim</A>
+</TD><TD>G</TD><TD>int</TD><TD ALIGN="CENTER">2</TD><TD>2</TD><TD>sfdp, fdp, neato only</TD> </TR>
+ <TR><TD><A NAME=a:dimen HREF=#d:dimen>dimen</A>
+</TD><TD>G</TD><TD>int</TD><TD ALIGN="CENTER">2</TD><TD>2</TD><TD>sfdp, fdp, neato only</TD> </TR>
+ <TR><TD><A NAME=a:dir HREF=#d:dir>dir</A>
+</TD><TD>E</TD><TD><A HREF=#k:dirType>dirType</A>
+</TD><TD ALIGN="CENTER">forward(directed)<BR>none(undirected)</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:diredgeconstraints HREF=#d:diredgeconstraints>diredgeconstraints</A>
+</TD><TD>G</TD><TD>string<BR><A HREF=#k:bool>bool</A>
+</TD><TD ALIGN="CENTER">false</TD><TD></TD><TD>neato only</TD> </TR>
+ <TR><TD><A NAME=a:distortion HREF=#d:distortion>distortion</A>
+</TD><TD>N</TD><TD>double</TD><TD ALIGN="CENTER">0.0</TD><TD>-100.0</TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:dpi HREF=#d:dpi>dpi</A>
+</TD><TD>G</TD><TD>double</TD><TD ALIGN="CENTER">96.0<BR>0.0</TD><TD></TD><TD>svg, bitmap output only</TD> </TR>
+ <TR><TD><A NAME=a:edgehref HREF=#d:edgehref>edgehref</A>
+</TD><TD>E</TD><TD><A HREF=#k:lblString>lblString</A>
+</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD>svg, map only</TD> </TR>
+ <TR><TD><A NAME=a:edgetarget HREF=#d:edgetarget>edgetarget</A>
+</TD><TD>E</TD><TD><A HREF=#k:escString>escString</A>
+</TD><TD ALIGN="CENTER"><none></TD><TD></TD><TD>svg, map only</TD> </TR>
+ <TR><TD><A NAME=a:edgetooltip HREF=#d:edgetooltip>edgetooltip</A>
+</TD><TD>E</TD><TD><A HREF=#k:escString>escString</A>
+</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD>svg, cmap only</TD> </TR>
+ <TR><TD><A NAME=a:edgeURL HREF=#d:edgeURL>edgeURL</A>
+</TD><TD>E</TD><TD><A HREF=#k:lblString>lblString</A>
+</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD>svg, map only</TD> </TR>
+ <TR><TD><A NAME=a:epsilon HREF=#d:epsilon>epsilon</A>
+</TD><TD>G</TD><TD>double</TD><TD ALIGN="CENTER">.0001 * # nodes(mode == KK)<BR>.0001(mode == major)</TD><TD></TD><TD>neato only</TD> </TR>
+ <TR><TD><A NAME=a:esep HREF=#d:esep>esep</A>
+</TD><TD>G</TD><TD>double<BR><A HREF=#k:pointf>pointf</A>
+</TD><TD ALIGN="CENTER">+3</TD><TD></TD><TD>not dot</TD> </TR>
+ <TR><TD><A NAME=a:fillcolor HREF=#d:fillcolor>fillcolor</A>
+</TD><TD>NC</TD><TD><A HREF=#k:color>color</A>
+</TD><TD ALIGN="CENTER">lightgrey(nodes)<BR>black(clusters)</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:fixedsize HREF=#d:fixedsize>fixedsize</A>
+</TD><TD>N</TD><TD><A HREF=#k:bool>bool</A>
+</TD><TD ALIGN="CENTER">false</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:fontcolor HREF=#d:fontcolor>fontcolor</A>
+</TD><TD>ENGC</TD><TD><A HREF=#k:color>color</A>
+</TD><TD ALIGN="CENTER">black</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:fontname HREF=#d:fontname>fontname</A>
+</TD><TD>ENGC</TD><TD>string</TD><TD ALIGN="CENTER">"Times-Roman"</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:fontnames HREF=#d:fontnames>fontnames</A>
+</TD><TD>G</TD><TD>string</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD>svg only</TD> </TR>
+ <TR><TD><A NAME=a:fontpath HREF=#d:fontpath>fontpath</A>
+</TD><TD>G</TD><TD>string</TD><TD ALIGN="CENTER">system-dependent</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:fontsize HREF=#d:fontsize>fontsize</A>
+</TD><TD>ENGC</TD><TD>double</TD><TD ALIGN="CENTER">14.0</TD><TD>1.0</TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:group HREF=#d:group>group</A>
+</TD><TD>N</TD><TD>string</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD>dot only</TD> </TR>
+ <TR><TD><A NAME=a:headclip HREF=#d:headclip>headclip</A>
+</TD><TD>E</TD><TD><A HREF=#k:bool>bool</A>
+</TD><TD ALIGN="CENTER">true</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:headhref HREF=#d:headhref>headhref</A>
+</TD><TD>E</TD><TD><A HREF=#k:lblString>lblString</A>
+</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD>svg, map only</TD> </TR>
+ <TR><TD><A NAME=a:headlabel HREF=#d:headlabel>headlabel</A>
+</TD><TD>E</TD><TD><A HREF=#k:lblString>lblString</A>
+</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:headport HREF=#d:headport>headport</A>
+</TD><TD>E</TD><TD><A HREF=#k:portPos>portPos</A>
+</TD><TD ALIGN="CENTER">center</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:headtarget HREF=#d:headtarget>headtarget</A>
+</TD><TD>E</TD><TD><A HREF=#k:escString>escString</A>
+</TD><TD ALIGN="CENTER"><none></TD><TD></TD><TD>svg, map only</TD> </TR>
+ <TR><TD><A NAME=a:headtooltip HREF=#d:headtooltip>headtooltip</A>
+</TD><TD>E</TD><TD><A HREF=#k:escString>escString</A>
+</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD>svg, cmap only</TD> </TR>
+ <TR><TD><A NAME=a:headURL HREF=#d:headURL>headURL</A>
+</TD><TD>E</TD><TD><A HREF=#k:lblString>lblString</A>
+</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD>svg, map only</TD> </TR>
+ <TR><TD><A NAME=a:height HREF=#d:height>height</A>
+</TD><TD>N</TD><TD>double</TD><TD ALIGN="CENTER">0.5</TD><TD>0.02</TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:href HREF=#d:href>href</A>
+</TD><TD>E</TD><TD><A HREF=#k:lblString>lblString</A>
+</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD>svg, postscript, map only</TD> </TR>
+ <TR><TD><A NAME=a:id HREF=#d:id>id</A>
+</TD><TD>GNE</TD><TD><A HREF=#k:lblString>lblString</A>
+</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD>svg, postscript, map only</TD> </TR>
+ <TR><TD><A NAME=a:image HREF=#d:image>image</A>
+</TD><TD>N</TD><TD>string</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:imagescale HREF=#d:imagescale>imagescale</A>
+</TD><TD>N</TD><TD><A HREF=#k:bool>bool</A>
+<BR>string</TD><TD ALIGN="CENTER">false</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:K HREF=#d:K>K</A>
+</TD><TD>GC</TD><TD>double</TD><TD ALIGN="CENTER">0.3</TD><TD>0</TD><TD>sfdp, fdp only</TD> </TR>
+ <TR><TD><A NAME=a:label HREF=#d:label>label</A>
+</TD><TD>ENGC</TD><TD><A HREF=#k:lblString>lblString</A>
+</TD><TD ALIGN="CENTER">"\N" (nodes)<BR>"" (otherwise)</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:labelangle HREF=#d:labelangle>labelangle</A>
+</TD><TD>E</TD><TD>double</TD><TD ALIGN="CENTER">-25.0</TD><TD>-180.0</TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:labeldistance HREF=#d:labeldistance>labeldistance</A>
+</TD><TD>E</TD><TD>double</TD><TD ALIGN="CENTER">1.0</TD><TD>0.0</TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:labelfloat HREF=#d:labelfloat>labelfloat</A>
+</TD><TD>E</TD><TD><A HREF=#k:bool>bool</A>
+</TD><TD ALIGN="CENTER">false</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:labelfontcolor HREF=#d:labelfontcolor>labelfontcolor</A>
+</TD><TD>E</TD><TD><A HREF=#k:color>color</A>
+</TD><TD ALIGN="CENTER">black</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:labelfontname HREF=#d:labelfontname>labelfontname</A>
+</TD><TD>E</TD><TD>string</TD><TD ALIGN="CENTER">"Times-Roman"</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:labelfontsize HREF=#d:labelfontsize>labelfontsize</A>
+</TD><TD>E</TD><TD>double</TD><TD ALIGN="CENTER">14.0</TD><TD>1.0</TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:labelhref HREF=#d:labelhref>labelhref</A>
+</TD><TD>E</TD><TD><A HREF=#k:lblString>lblString</A>
+</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD>svg, map only</TD> </TR>
+ <TR><TD><A NAME=a:labeljust HREF=#d:labeljust>labeljust</A>
+</TD><TD>GC</TD><TD>string</TD><TD ALIGN="CENTER">"c"</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:labelloc HREF=#d:labelloc>labelloc</A>
+</TD><TD>GC</TD><TD>string</TD><TD ALIGN="CENTER">"t"(clusters)<BR>"b"(root graphs)</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=aa:labelloc HREF=#dd:labelloc>labelloc</A>
+</TD><TD>N</TD><TD>string</TD><TD ALIGN="CENTER">"c"(clusters)</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:labeltarget HREF=#d:labeltarget>labeltarget</A>
+</TD><TD>E</TD><TD><A HREF=#k:escString>escString</A>
+</TD><TD ALIGN="CENTER"><none></TD><TD></TD><TD>svg, map only</TD> </TR>
+ <TR><TD><A NAME=a:labeltooltip HREF=#d:labeltooltip>labeltooltip</A>
+</TD><TD>E</TD><TD><A HREF=#k:escString>escString</A>
+</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD>svg, cmap only</TD> </TR>
+ <TR><TD><A NAME=a:labelURL HREF=#d:labelURL>labelURL</A>
+</TD><TD>E</TD><TD><A HREF=#k:lblString>lblString</A>
+</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD>svg, map only</TD> </TR>
+ <TR><TD><A NAME=a:landscape HREF=#d:landscape>landscape</A>
+</TD><TD>G</TD><TD><A HREF=#k:bool>bool</A>
+</TD><TD ALIGN="CENTER">false</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:layer HREF=#d:layer>layer</A>
+</TD><TD>EN</TD><TD><A HREF=#k:layerRange>layerRange</A>
+</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:layers HREF=#d:layers>layers</A>
+</TD><TD>G</TD><TD><A HREF=#k:layerList>layerList</A>
+</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:layersep HREF=#d:layersep>layersep</A>
+</TD><TD>G</TD><TD>string</TD><TD ALIGN="CENTER">" :\t"</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:layout HREF=#d:layout>layout</A>
+</TD><TD>G</TD><TD>string</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:len HREF=#d:len>len</A>
+</TD><TD>E</TD><TD>double</TD><TD ALIGN="CENTER">1.0(neato)<BR>0.3(fdp)</TD><TD></TD><TD>fdp, neato only</TD> </TR>
+ <TR><TD><A NAME=a:levels HREF=#d:levels>levels</A>
+</TD><TD>G</TD><TD>int</TD><TD ALIGN="CENTER">MAXINT</TD><TD>0.0</TD><TD>sfdp only</TD> </TR>
+ <TR><TD><A NAME=a:levelsgap HREF=#d:levelsgap>levelsgap</A>
+</TD><TD>G</TD><TD>double</TD><TD ALIGN="CENTER">0.0</TD><TD></TD><TD>neato only</TD> </TR>
+ <TR><TD><A NAME=a:lhead HREF=#d:lhead>lhead</A>
+</TD><TD>E</TD><TD>string</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD>dot only</TD> </TR>
+ <TR><TD><A NAME=a:lp HREF=#d:lp>lp</A>
+</TD><TD>EGC</TD><TD><A HREF=#k:point>point</A>
+</TD><TD ALIGN="CENTER"></TD><TD></TD><TD>write only</TD> </TR>
+ <TR><TD><A NAME=a:ltail HREF=#d:ltail>ltail</A>
+</TD><TD>E</TD><TD>string</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD>dot only</TD> </TR>
+ <TR><TD><A NAME=a:margin HREF=#d:margin>margin</A>
+</TD><TD>NG</TD><TD>double<BR><A HREF=#k:pointf>pointf</A>
+</TD><TD ALIGN="CENTER"><device-dependent></TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:maxiter HREF=#d:maxiter>maxiter</A>
+</TD><TD>G</TD><TD>int</TD><TD ALIGN="CENTER">100 * # nodes(mode == KK)<BR>200(mode == major)<BR>600(fdp)</TD><TD></TD><TD>fdp, neato only</TD> </TR>
+ <TR><TD><A NAME=a:mclimit HREF=#d:mclimit>mclimit</A>
+</TD><TD>G</TD><TD>double</TD><TD ALIGN="CENTER">1.0</TD><TD></TD><TD>dot only</TD> </TR>
+ <TR><TD><A NAME=a:mindist HREF=#d:mindist>mindist</A>
+</TD><TD>G</TD><TD>double</TD><TD ALIGN="CENTER">1.0</TD><TD>0.0</TD><TD>circo only</TD> </TR>
+ <TR><TD><A NAME=a:minlen HREF=#d:minlen>minlen</A>
+</TD><TD>E</TD><TD>int</TD><TD ALIGN="CENTER">1</TD><TD>0</TD><TD>dot only</TD> </TR>
+ <TR><TD><A NAME=a:mode HREF=#d:mode>mode</A>
+</TD><TD>G</TD><TD>string</TD><TD ALIGN="CENTER">"major"</TD><TD></TD><TD>neato only</TD> </TR>
+ <TR><TD><A NAME=a:model HREF=#d:model>model</A>
+</TD><TD>G</TD><TD>string</TD><TD ALIGN="CENTER">"shortpath"</TD><TD></TD><TD>neato only</TD> </TR>
+ <TR><TD><A NAME=a:mosek HREF=#d:mosek>mosek</A>
+</TD><TD>G</TD><TD><A HREF=#k:bool>bool</A>
+</TD><TD ALIGN="CENTER">false</TD><TD></TD><TD>neato only</TD> </TR>
+ <TR><TD><A NAME=a:nodesep HREF=#d:nodesep>nodesep</A>
+</TD><TD>G</TD><TD>double</TD><TD ALIGN="CENTER">0.25</TD><TD>0.02</TD><TD>dot only</TD> </TR>
+ <TR><TD><A NAME=a:nojustify HREF=#d:nojustify>nojustify</A>
+</TD><TD>GCNE</TD><TD><A HREF=#k:bool>bool</A>
+</TD><TD ALIGN="CENTER">false</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:normalize HREF=#d:normalize>normalize</A>
+</TD><TD>G</TD><TD><A HREF=#k:bool>bool</A>
+</TD><TD ALIGN="CENTER">false</TD><TD></TD><TD>not dot</TD> </TR>
+ <TR><TD><A NAME=a:nslimit HREF=#d:nslimit>nslimit</A>
+<BR><A NAME=a:nslimit1 HREF=#d:nslimit1>nslimit1</A>
+</TD><TD>G</TD><TD>double</TD><TD ALIGN="CENTER"></TD><TD></TD><TD>dot only</TD> </TR>
+ <TR><TD><A NAME=a:ordering HREF=#d:ordering>ordering</A>
+</TD><TD>G</TD><TD>string</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD>dot only</TD> </TR>
+ <TR><TD><A NAME=a:orientation HREF=#d:orientation>orientation</A>
+</TD><TD>N</TD><TD>double</TD><TD ALIGN="CENTER">0.0</TD><TD>360.0</TD><TD></TD> </TR>
+ <TR><TD><A NAME=aa:orientation HREF=#dd:orientation>orientation</A>
+</TD><TD>G</TD><TD>string</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:outputorder HREF=#d:outputorder>outputorder</A>
+</TD><TD>G</TD><TD><A HREF=#k:outputMode>outputMode</A>
+</TD><TD ALIGN="CENTER">breadthfirst</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:overlap HREF=#d:overlap>overlap</A>
+</TD><TD>G</TD><TD>string<BR><A HREF=#k:bool>bool</A>
+</TD><TD ALIGN="CENTER">true</TD><TD></TD><TD>not dot</TD> </TR>
+ <TR><TD><A NAME=a:pack HREF=#d:pack>pack</A>
+</TD><TD>G</TD><TD><A HREF=#k:bool>bool</A>
+<BR>int</TD><TD ALIGN="CENTER">false</TD><TD></TD><TD>not dot</TD> </TR>
+ <TR><TD><A NAME=a:packmode HREF=#d:packmode>packmode</A>
+</TD><TD>G</TD><TD><A HREF=#k:packMode>packMode</A>
+</TD><TD ALIGN="CENTER">node</TD><TD></TD><TD>not dot</TD> </TR>
+ <TR><TD><A NAME=a:pad HREF=#d:pad>pad</A>
+</TD><TD>G</TD><TD>double<BR><A HREF=#k:pointf>pointf</A>
+</TD><TD ALIGN="CENTER">0.0555 (4 points)</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:page HREF=#d:page>page</A>
+</TD><TD>G</TD><TD><A HREF=#k:pointf>pointf</A>
+</TD><TD ALIGN="CENTER"></TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:pagedir HREF=#d:pagedir>pagedir</A>
+</TD><TD>G</TD><TD><A HREF=#k:pagedir>pagedir</A>
+</TD><TD ALIGN="CENTER">BL</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:pencolor HREF=#d:pencolor>pencolor</A>
+</TD><TD>C</TD><TD><A HREF=#k:color>color</A>
+</TD><TD ALIGN="CENTER">black</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:penwidth HREF=#d:penwidth>penwidth</A>
+</TD><TD>CNE</TD><TD>double</TD><TD ALIGN="CENTER">1.0</TD><TD>0.0</TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:peripheries HREF=#d:peripheries>peripheries</A>
+</TD><TD>NC</TD><TD>int</TD><TD ALIGN="CENTER">shape default(nodes)<BR>1(clusters)</TD><TD>0</TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:pin HREF=#d:pin>pin</A>
+</TD><TD>N</TD><TD><A HREF=#k:bool>bool</A>
+</TD><TD ALIGN="CENTER">false</TD><TD></TD><TD>fdp, neato only</TD> </TR>
+ <TR><TD><A NAME=a:pos HREF=#d:pos>pos</A>
+</TD><TD>EN</TD><TD><A HREF=#k:point>point</A>
+<BR><A HREF=#k:splineType>splineType</A>
+</TD><TD ALIGN="CENTER"></TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:quadtree HREF=#d:quadtree>quadtree</A>
+</TD><TD>G</TD><TD><A HREF=#k:quadType>quadType</A>
+<BR><A HREF=#k:bool>bool</A>
+</TD><TD ALIGN="CENTER">"normal"</TD><TD></TD><TD>sfdp only</TD> </TR>
+ <TR><TD><A NAME=a:quantum HREF=#d:quantum>quantum</A>
+</TD><TD>G</TD><TD>double</TD><TD ALIGN="CENTER">0.0</TD><TD>0.0</TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:rank HREF=#d:rank>rank</A>
+</TD><TD>S</TD><TD><A HREF=#k:rankType>rankType</A>
+</TD><TD ALIGN="CENTER"></TD><TD></TD><TD>dot only</TD> </TR>
+ <TR><TD><A NAME=a:rankdir HREF=#d:rankdir>rankdir</A>
+</TD><TD>G</TD><TD><A HREF=#k:rankdir>rankdir</A>
+</TD><TD ALIGN="CENTER">TB</TD><TD></TD><TD>dot only</TD> </TR>
+ <TR><TD><A NAME=a:ranksep HREF=#d:ranksep>ranksep</A>
+</TD><TD>G</TD><TD>double</TD><TD ALIGN="CENTER">0.5(dot)<BR>1.0(twopi)</TD><TD>0.02</TD><TD>twopi, dot only</TD> </TR>
+ <TR><TD><A NAME=a:ratio HREF=#d:ratio>ratio</A>
+</TD><TD>G</TD><TD>double<BR>string</TD><TD ALIGN="CENTER"></TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:rects HREF=#d:rects>rects</A>
+</TD><TD>N</TD><TD><A HREF=#k:rect>rect</A>
+</TD><TD ALIGN="CENTER"></TD><TD></TD><TD>write only</TD> </TR>
+ <TR><TD><A NAME=a:regular HREF=#d:regular>regular</A>
+</TD><TD>N</TD><TD><A HREF=#k:bool>bool</A>
+</TD><TD ALIGN="CENTER">false</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:remincross HREF=#d:remincross>remincross</A>
+</TD><TD>G</TD><TD><A HREF=#k:bool>bool</A>
+</TD><TD ALIGN="CENTER">false</TD><TD></TD><TD>dot only</TD> </TR>
+ <TR><TD><A NAME=a:repulsiveforce HREF=#d:repulsiveforce>repulsiveforce</A>
+</TD><TD>G</TD><TD>double</TD><TD ALIGN="CENTER">1.0</TD><TD>0.0</TD><TD>sfdp only</TD> </TR>
+ <TR><TD><A NAME=a:resolution HREF=#d:resolution>resolution</A>
+</TD><TD>G</TD><TD>double</TD><TD ALIGN="CENTER">96.0<BR>0.0</TD><TD></TD><TD>svg, bitmap output only</TD> </TR>
+ <TR><TD><A NAME=a:root HREF=#d:root>root</A>
+</TD><TD>GN</TD><TD>string<BR><A HREF=#k:bool>bool</A>
+</TD><TD ALIGN="CENTER">""(graphs)<BR>false(nodes)</TD><TD></TD><TD>circo, twopi only</TD> </TR>
+ <TR><TD><A NAME=a:rotate HREF=#d:rotate>rotate</A>
+</TD><TD>G</TD><TD>int</TD><TD ALIGN="CENTER">0</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:samehead HREF=#d:samehead>samehead</A>
+</TD><TD>E</TD><TD>string</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD>dot only</TD> </TR>
+ <TR><TD><A NAME=a:sametail HREF=#d:sametail>sametail</A>
+</TD><TD>E</TD><TD>string</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD>dot only</TD> </TR>
+ <TR><TD><A NAME=a:samplepoints HREF=#d:samplepoints>samplepoints</A>
+</TD><TD>N</TD><TD>int</TD><TD ALIGN="CENTER">8(output)<BR>20(overlap and image maps)</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:searchsize HREF=#d:searchsize>searchsize</A>
+</TD><TD>G</TD><TD>int</TD><TD ALIGN="CENTER">30</TD><TD></TD><TD>dot only</TD> </TR>
+ <TR><TD><A NAME=a:sep HREF=#d:sep>sep</A>
+</TD><TD>G</TD><TD>double<BR><A HREF=#k:pointf>pointf</A>
+</TD><TD ALIGN="CENTER">+4</TD><TD></TD><TD>not dot</TD> </TR>
+ <TR><TD><A NAME=a:shape HREF=#d:shape>shape</A>
+</TD><TD>N</TD><TD><A HREF=#k:shape>shape</A>
+</TD><TD ALIGN="CENTER">ellipse</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:shapefile HREF=#d:shapefile>shapefile</A>
+</TD><TD>N</TD><TD>string</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:showboxes HREF=#d:showboxes>showboxes</A>
+</TD><TD>ENG</TD><TD>int</TD><TD ALIGN="CENTER">0</TD><TD>0</TD><TD>dot only</TD> </TR>
+ <TR><TD><A NAME=a:sides HREF=#d:sides>sides</A>
+</TD><TD>N</TD><TD>int</TD><TD ALIGN="CENTER">4</TD><TD>0</TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:size HREF=#d:size>size</A>
+</TD><TD>G</TD><TD><A HREF=#k:pointf>pointf</A>
+</TD><TD ALIGN="CENTER"></TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:skew HREF=#d:skew>skew</A>
+</TD><TD>N</TD><TD>double</TD><TD ALIGN="CENTER">0.0</TD><TD>-100.0</TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:smoothing HREF=#d:smoothing>smoothing</A>
+</TD><TD>G</TD><TD><A HREF=#k:smoothType>smoothType</A>
+</TD><TD ALIGN="CENTER">"none"</TD><TD></TD><TD>sfdp only</TD> </TR>
+ <TR><TD><A NAME=a:splines HREF=#d:splines>splines</A>
+</TD><TD>G</TD><TD><A HREF=#k:bool>bool</A>
+<BR>string</TD><TD ALIGN="CENTER"></TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:start HREF=#d:start>start</A>
+</TD><TD>G</TD><TD><A HREF=#k:startType>startType</A>
+</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD>fdp, neato only</TD> </TR>
+ <TR><TD><A NAME=a:style HREF=#d:style>style</A>
+</TD><TD>ENC</TD><TD><A HREF=#k:style>style</A>
+</TD><TD ALIGN="CENTER"></TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:stylesheet HREF=#d:stylesheet>stylesheet</A>
+</TD><TD>G</TD><TD>string</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD>svg only</TD> </TR>
+ <TR><TD><A NAME=a:tailclip HREF=#d:tailclip>tailclip</A>
+</TD><TD>E</TD><TD><A HREF=#k:bool>bool</A>
+</TD><TD ALIGN="CENTER">true</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:tailhref HREF=#d:tailhref>tailhref</A>
+</TD><TD>E</TD><TD><A HREF=#k:lblString>lblString</A>
+</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD>svg, map only</TD> </TR>
+ <TR><TD><A NAME=a:taillabel HREF=#d:taillabel>taillabel</A>
+</TD><TD>E</TD><TD><A HREF=#k:lblString>lblString</A>
+</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:tailport HREF=#d:tailport>tailport</A>
+</TD><TD>E</TD><TD><A HREF=#k:portPos>portPos</A>
+</TD><TD ALIGN="CENTER">center</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:tailtarget HREF=#d:tailtarget>tailtarget</A>
+</TD><TD>E</TD><TD><A HREF=#k:escString>escString</A>
+</TD><TD ALIGN="CENTER"><none></TD><TD></TD><TD>svg, map only</TD> </TR>
+ <TR><TD><A NAME=a:tailtooltip HREF=#d:tailtooltip>tailtooltip</A>
+</TD><TD>E</TD><TD><A HREF=#k:escString>escString</A>
+</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD>svg, cmap only</TD> </TR>
+ <TR><TD><A NAME=a:tailURL HREF=#d:tailURL>tailURL</A>
+</TD><TD>E</TD><TD><A HREF=#k:lblString>lblString</A>
+</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD>svg, map only</TD> </TR>
+ <TR><TD><A NAME=a:target HREF=#d:target>target</A>
+</TD><TD>ENGC</TD><TD><A HREF=#k:escString>escString</A>
+<BR>string</TD><TD ALIGN="CENTER"><none></TD><TD></TD><TD>svg, map only</TD> </TR>
+ <TR><TD><A NAME=a:tooltip HREF=#d:tooltip>tooltip</A>
+</TD><TD>NEC</TD><TD><A HREF=#k:escString>escString</A>
+</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD>svg, cmap only</TD> </TR>
+ <TR><TD><A NAME=a:truecolor HREF=#d:truecolor>truecolor</A>
+</TD><TD>G</TD><TD><A HREF=#k:bool>bool</A>
+</TD><TD ALIGN="CENTER"></TD><TD></TD><TD>bitmap output only</TD> </TR>
+ <TR><TD><A NAME=a:URL HREF=#d:URL>URL</A>
+</TD><TD>ENGC</TD><TD><A HREF=#k:lblString>lblString</A>
+</TD><TD ALIGN="CENTER"><none></TD><TD></TD><TD>svg, postscript, map only</TD> </TR>
+ <TR><TD><A NAME=a:vertices HREF=#d:vertices>vertices</A>
+</TD><TD>N</TD><TD><A HREF=#k:pointfList>pointfList</A>
+</TD><TD ALIGN="CENTER"></TD><TD></TD><TD>write only</TD> </TR>
+ <TR><TD><A NAME=a:viewport HREF=#d:viewport>viewport</A>
+</TD><TD>G</TD><TD><A HREF=#k:viewPort>viewPort</A>
+</TD><TD ALIGN="CENTER">""</TD><TD></TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:voro_margin HREF=#d:voro_margin>voro_margin</A>
+</TD><TD>G</TD><TD>double</TD><TD ALIGN="CENTER">0.05</TD><TD>0.0</TD><TD>not dot</TD> </TR>
+ <TR><TD><A NAME=a:weight HREF=#d:weight>weight</A>
+</TD><TD>E</TD><TD>double</TD><TD ALIGN="CENTER">1.0</TD><TD>0(dot)<BR>1(neato,fdp,sfdp)</TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:width HREF=#d:width>width</A>
+</TD><TD>N</TD><TD>double</TD><TD ALIGN="CENTER">0.75</TD><TD>0.01</TD><TD></TD> </TR>
+ <TR><TD><A NAME=a:z HREF=#d:z>z</A>
+</TD><TD>N</TD><TD>double</TD><TD ALIGN="CENTER">0.0</TD><TD>-MAXFLOAT<BR>-1000</TD><TD></TD> </TR>
+</TABLE>
+<HR>
+<H1>Attribute Descriptions</H1>
+<DL>
+<DT><A NAME=d:arrowhead HREF=#a:arrowhead><STRONG>arrowhead</STRONG></A>
+<DD> Style of arrowhead on the head node of an edge.
+ See also the <A HREF=#d:dir>dir</A> attribute,
+ and a <A HREF=#h:undir_note>limitation</A>.
+
+<DT><A NAME=d:arrowsize HREF=#a:arrowsize><STRONG>arrowsize</STRONG></A>
+<DD> Multiplicative scale factor for arrowheads.
+
+<DT><A NAME=d:arrowtail HREF=#a:arrowtail><STRONG>arrowtail</STRONG></A>
+<DD> Style of arrowhead on the tail node of an edge.
+ See also the <A HREF=#d:dir>dir</A> attribute,
+ and a <A HREF=#h:undir_note>limitation</A>.
+
+<DT><A NAME=d:bb HREF=#a:bb><STRONG>bb</STRONG></A>
+<DD> Bounding box of drawing in integer points.
+
+<DT><A NAME=d:bgcolor HREF=#a:bgcolor><STRONG>bgcolor</STRONG></A>
+<DD> When attached to the root graph, this color is used as the background for
+ entire canvas. When a cluster attribute, it is used as the initial
+ background for the cluster. If a cluster has a filled
+ <A HREF=#d:style>style</A>, the
+ cluster's <A HREF=#d:fillcolor>fillcolor</A> will overlay the
+ background color.
+ <P>
+ If no background color is specified for the root graph, no graphics
+ operation are performed on the background. This works fine for
+ PostScript but for bitmap output, all bits are initialized to something.
+ This means that when the bitmap output is included in some other
+ document, all of the bits within the bitmap's bounding box will be
+ set, overwriting whatever color or graphics where already on the page.
+ If this effect is not desired, and you only want to set bits explicitly
+ assigned in drawing the graph, set <B>bgcolor</B>="transparent".
+
+<DT><A NAME=d:center HREF=#a:center><STRONG>center</STRONG></A>
+<DD> If true, the drawing is centered in the output canvas.
+
+<DT><A NAME=d:charset HREF=#a:charset><STRONG>charset</STRONG></A>
+<DD> Specifies the character encoding used when interpreting string input
+ as a text label. The default value is <TT>"UTF-8"</TT>.
+ The other legal value is <TT>"iso-8859-1"</TT> or,
+ equivalently,
+ <TT>"Latin1"</TT>. The <B>charset</B> attribute is case-insensitive.
+ Note that if the character encoding used in the input does not
+ match the <B>charset</B> value, the resulting output may be very strange.
+
+<DT><A NAME=d:clusterrank HREF=#a:clusterrank><STRONG>clusterrank</STRONG></A>
+<DD> Mode used for handling clusters. If <B>clusterrank</B> is "local", a
+ subgraph whose name begins with "cluster" is given special treatment.
+ The subgraph is laid out separately, and then integrated as a unit into
+ its parent graph, with a bounding rectangle drawn about it.
+ If the cluster has a <A HREF=#d:label>label</A> parameter, this label
+ is displayed within the rectangle.
+ Note also that there can be clusters within clusters.
+ At present, the modes "global" and "none"
+ appear to be identical, both turning off the special cluster processing.
+
+<DT><A NAME=d:color HREF=#a:color><STRONG>color</STRONG></A>
+<DD> Basic drawing color for graphics, not text. For the latter, use the
+ <A HREF=#d.fontcolor>fontcolor</A> attribute.
+ <P>
+ For edges, the value
+ can either be a single color or a <A HREF=#k:colorList>colorList</A>.
+ In the latter case, the edge is drawn using parallel splines or lines,
+ one for each color in the list, in the order given.
+ The head arrow, if any, is drawn using the first color in the list,
+ and the tail arrow, if any, the second color. This supports the common
+ case of drawing opposing edges, but using parallel splines instead of
+ separately routed multiedges. For example, the graph
+ <PRE>
+ digraph G {
+ a -> b [dir=both color="red:blue"]
+ }
+ </PRE>
+ yields<BR>
+ <IMG SRC="colorlist.gif">
+
+<DT><A NAME=d:colorscheme HREF=#a:colorscheme><STRONG>colorscheme</STRONG></A>
+<DD> This attribute specifies a color scheme namespace. If defined, it specifies
+ the context for interpreting color names. In particular, if a
+ <A HREF=#k:color>color</A> value has form <TT>"xxx"</TT> or <TT>"//xxx"</TT>,
+ then the
+ color <TT>xxx</TT> will be evaluated according to the current color scheme.
+ If no color scheme is set, the standard X11 naming is used.
+ For example, if <TT>colorscheme=bugn9</TT>, then <TT>color=7</TT>
+ is interpreted as <TT>"/bugn9/7"</TT>.
+
+<DT><A NAME=d:comment HREF=#a:comment><STRONG>comment</STRONG></A>
+<DD> Comments are inserted into output. Device-dependent
+
+<DT><A NAME=d:compound HREF=#a:compound><STRONG>compound</STRONG></A>
+<DD> If true, allow edges between clusters. (See <A HREF=#d:lhead>lhead</A>
+ and <A HREF=#d:ltail>ltail</A> below.)
+
+<DT><A NAME=d:concentrate HREF=#a:concentrate><STRONG>concentrate</STRONG></A>
+<DD> If true, use edge concentrators.
+
+<DT><A NAME=d:constraint HREF=#a:constraint><STRONG>constraint</STRONG></A>
+<DD> If false, the edge is not used in ranking the nodes. For example,
+ in the graph
+ <PRE>
+ digraph G {
+ a -> c;
+ a -> b;
+ b -> c [constraint=false];
+ }
+ </PRE>
+ the edge <CODE>b -> c</CODE> does not add a constraint during rank
+ assignment, so the only constraints are that a be above b and c,
+ yielding the graph:<BR>
+ <IMG SRC="constraint.gif">
+
+<DT><A NAME=d:Damping HREF=#a:Damping><STRONG>Damping</STRONG></A>
+<DD> Factor damping force motions. On each iteration, a nodes movement
+ is limited to this factor of its potential motion. By being less than
+ 1.0, the system tends to ``cool'', thereby preventing cycling.
+
+<DT><A NAME=d:decorate HREF=#a:decorate><STRONG>decorate</STRONG></A>
+<DD> If true, attach edge label to edge by a 2-segment
+ polyline, underlining the label, then going to the closest point of spline.
+
+<DT><A NAME=d:defaultdist HREF=#a:defaultdist><STRONG>defaultdist</STRONG></A>
+<DD> This specifies the distance between nodes in separate connected
+ components. If set too small, connected components may overlap.
+ Only applicable if <A HREF=#d:pack>pack</A>=false.
+
+<DT><A NAME=d:dim HREF=#a:dim><STRONG>dim</STRONG></A>
+<DD> Set the number of dimensions used for the layout. The maximum value
+ allowed is 10.
+
+<DT><A NAME=d:dimen HREF=#a:dimen><STRONG>dimen</STRONG></A>
+<DD> Set the number of dimensions used for rendering.
+ The maximum value allowed is 10.
+ If both <TT>dimen</TT> and <TT>dim</TT> are set, the latter specifies
+ the dimension used for layout, and the former for rendering.
+ If only <TT>dimen</TT> is set, this is used for both layout and rendering
+ dimensions.
+
+<DT><A NAME=d:dir HREF=#a:dir><STRONG>dir</STRONG></A>
+<DD> Set edge type for drawing arrowheads. This indicates which ends of the
+ edge should be decorated with an arrowhead. The actual style of the
+ arrowhead can be specified using the <A HREF=#d:arrowhead>arrowhead</A>
+ and <A HREF=#d:arrowtail>arrowtail</A> attributes.
+ See <A HREF=#h:undir_note>limitation</A>.
+
+<DT><A NAME=d:diredgeconstraints HREF=#a:diredgeconstraints><STRONG>diredgeconstraints</STRONG></A>
+<DD> Only valid when <A HREF=#d:mode>mode</A>="ipsep".
+ If true, constraints are generated for each edge in the largest (heuristic)
+ directed acyclic subgraph such that the edge must point downwards.
+ If "hier", generates level constraints similar to those used with
+ <A HREF=#d:mode>mode</A>="hier". The main difference is that, in the latter
+ case, only these constraints are involved, so a faster solver can be used.
+
+<DT><A NAME=d:distortion HREF=#a:distortion><STRONG>distortion</STRONG></A>
+<DD> Distortion factor for <A HREF=#d:shape><B>shape</B></A>=polygon.
+ Positive values cause top part to
+ be larger than bottom; negative values do the opposite.
+
+<DT><A NAME=d:dpi HREF=#a:dpi><STRONG>dpi</STRONG></A>
+<DD> This specifies the expected number of pixels per inch on a display device.
+ For bitmap output, this guarantees that text rendering will be
+ done more accurately, both in size and in placement. For SVG output,
+ it is used to guarantee that the dimensions in the output correspond to
+ the correct number of points or inches.
+
+<DT><A NAME=d:edgehref HREF=#a:edgehref><STRONG>edgehref</STRONG></A>
+<DD> Synonym for <A HREF=#d:edgeURL>edgeURL</A>.
+
+<DT><A NAME=d:edgetarget HREF=#a:edgetarget><STRONG>edgetarget</STRONG></A>
+<DD> If the edge has a <A HREF=#d:URL>URL</A> or <A HREF=#d:edgeURL>edgeURL</A>
+ attribute, this attribute determines which window of the
+ browser is used
+ for the URL attached to the non-label part of the edge.
+ Setting it to "_graphviz" will open a new window if it
+ doesn't already exist, or reuse it if it does.
+ If undefined, the value of the <A HREF=#d:target>target</A> is used.
+
+<DT><A NAME=d:edgetooltip HREF=#a:edgetooltip><STRONG>edgetooltip</STRONG></A>
+<DD> Tooltip annotation attached to the non-label part of an edge.
+ This is used only if the edge has a <A HREF=#d:URL>URL</A>
+ or <A HREF=#d:edgeURL>edgeURL</A> attribute.
+
+<DT><A NAME=d:edgeURL HREF=#a:edgeURL><STRONG>edgeURL</STRONG></A>
+<DD> If <B>edgeURL</B> is defined, this is the link used for the non-label
+ parts of an edge. This value overrides any <A HREF=#d:URL>URL</A>
+ defined for the edge.
+ Also, this value is used near the head or tail node unless overridden
+ by a <A HREF=#d:headURL>headURL</A> or <A HREF=#d:tailURL>tailURL</A> value,
+ respectively.
+ See <A HREF=#h:undir_note>limitation</A>.
+
+<DT><A NAME=d:epsilon HREF=#a:epsilon><STRONG>epsilon</STRONG></A>
+<DD> Terminating condition. If the length squared of all energy gradients are
+ < <B>epsilon</B>, the algorithm stops.
+
+<DT><A NAME=d:esep HREF=#a:esep><STRONG>esep</STRONG></A>
+<DD> Margin used around polygons for purposes of spline edge routing.
+ The interpretation is the same as given for <A HREF=#d:sep>sep</A>.
+ This should normally be strictly less than <A HREF=#d:sep>sep</A>.
+
+<DT><A NAME=d:fillcolor HREF=#a:fillcolor><STRONG>fillcolor</STRONG></A>
+<DD> Color used to fill the background of a node or cluster
+ assuming <A HREF=#d:style>style</A>=filled.
+ If <B>fillcolor</B> is not defined, <A HREF=#d:color>color</A> is
+ used. (For clusters, if <B>color</B> is not defined,
+ <A HREF=#d:bgcolor>bgcolor</A> is used.) If this is not defined,
+ the default is used, except for
+ <A HREF=#d:shape><B>shape</B></A>=point or when the output
+ format is MIF,
+ which use black by default.
+ <P>
+ Note that a cluster inherits the root graph's attributes if defined.
+ Thus, if the root graph has defined a <B>fillcolor</B>, this will override a
+ <B>color</B> or <B>bgcolor</B> attribute set for the cluster.
+
+<DT><A NAME=d:fixedsize HREF=#a:fixedsize><STRONG>fixedsize</STRONG></A>
+<DD> If true, the node size is specified by the values of the
+ <A HREF=#d:width><B>width</B></A>
+ and <A HREF=#d:height><B>height</B></A> attributes only
+ and is not expanded to contain the text label.
+
+<DT><A NAME=d:fontcolor HREF=#a:fontcolor><STRONG>fontcolor</STRONG></A>
+<DD> Color used for text.
+
+<DT><A NAME=d:fontname HREF=#a:fontname><STRONG>fontname</STRONG></A>
+<DD> Font used for text. This very much depends on the output format and, for
+ non-bitmap output such as PostScript or SVG, the availability of the font
+ when the graph is displayed or printed. As such, it is best to rely on
+ font faces that are generally available, such as Times-Roman, Helvetica or
+ Courier.
+ <P>
+ If Graphviz was built using the
+ <A HREF=http://pdx.freedesktop.org/~fontconfig/fontconfig-user.html>fontconfig library</A>, the latter library
+ will be used to search for the font. However, if the <TT>fontname</TT> string
+ contains a slash character "/", it is treated as a pathname for the font
+ file, though font lookup will append the usual font suffixes.
+ <P>
+ If Graphviz does not use fontconfig, <TT>fontname</TT> will be
+ considered the name of a Type 1 or True Type font file.
+ If you specify <TT>fontname=schlbk</TT>, the tool will look for a
+ file named <TT>schlbk.ttf</TT> or <TT>schlbk.pfa</TT> or <TT>schlbk.pfb</TT>
+ in one of the directories specified by
+ the <A HREF=#d:fontpath>fontpath</A> attribute.
+ The lookup does support various aliases for the common fonts.
+
+<DT><A NAME=d:fontnames HREF=#a:fontnames><STRONG>fontnames</STRONG></A>
+<DD> Allows user control of how basic fontnames are represented in SVG output.
+ If <TT>fontnames</TT> is undefined or <TT>"svg"</TT>,
+ the output will try to use known SVG fontnames. For example, the
+ default font <TT>"Times-Roman"</TT> will be mapped to the
+ basic SVG font <TT>"serif"</TT>. This can be overridden by setting
+ <TT>fontnames</TT> to <TT>"ps"</TT> or <TT>"gd"</TT>.
+ In the former case, known PostScript font names such as
+ <TT>"Times-Roman"</TT> will be used in the output.
+ In the latter case, the fontconfig font conventions
+ are used. Thus, <TT>"Times-Roman"</TT> would be treated as
+ <TT>"Nimbus Roman No9 L"</TT>. These last two options are useful
+ with SVG viewers that support these richer fontname spaces.
+
+<DT><A NAME=d:fontpath HREF=#a:fontpath><STRONG>fontpath</STRONG></A>
+<DD> Directory list used by libgd to search for bitmap fonts if Graphviz
+ was not built with the fontconfig library.
+ If <B>fontpath</B> is not set, the environment
+ variable <TT>DOTFONTPATH</TT> is checked.
+ If that is not set, <TT>GDFONTPATH</TT> is checked.
+ If not set, libgd uses its compiled-in font path.
+ Note that fontpath is an attribute of the root graph.
+
+<DT><A NAME=d:fontsize HREF=#a:fontsize><STRONG>fontsize</STRONG></A>
+<DD> Font size, <A HREF=#points>in points</A>, used for text.
+
+<DT><A NAME=d:group HREF=#a:group><STRONG>group</STRONG></A>
+<DD> If the end points of an edge belong to the same group, i.e., have the
+ same group attribute, parameters are set to avoid crossings and keep
+ the edges straight.
+
+<DT><A NAME=d:headclip HREF=#a:headclip><STRONG>headclip</STRONG></A>
+<DD> If true, the head of an edge is clipped to the boundary of the head node;
+ otherwise, the end of the edge goes to the center of the node, or the
+ center of a port, if applicable.
+
+<DT><A NAME=d:headhref HREF=#a:headhref><STRONG>headhref</STRONG></A>
+<DD> Synonym for <A HREF=#d:headURL>headURL</A>.
+
+<DT><A NAME=d:headlabel HREF=#a:headlabel><STRONG>headlabel</STRONG></A>
+<DD> Text label to be placed near head of edge.
+ See <A HREF=#h:undir_note>limitation</A>.
+
+<DT><A NAME=d:headport HREF=#a:headport><STRONG>headport</STRONG></A>
+<DD> Indicates where on the head node to attach the head of the edge.
+ In the default case, the edge is aimed towards the center of the node,
+ and then clipped at the node boundary.
+ See <A HREF=#h:undir_note>limitation</A>.
+
+<DT><A NAME=d:headtarget HREF=#a:headtarget><STRONG>headtarget</STRONG></A>
+<DD> If the edge has a <A HREF=#d:headURL>headURL</A>,
+ this attribute determines which window of the
+ browser is used
+ for the URL. Setting it to "_graphviz" will open a new window if it
+ doesn't already exist, or reuse it if it does.
+ If undefined, the value of the <A HREF=#d:target>target</A> is used.
+
+<DT><A NAME=d:headtooltip HREF=#a:headtooltip><STRONG>headtooltip</STRONG></A>
+<DD> Tooltip annotation attached to the head of an edge. This is used only
+ if the edge has a <A HREF=#d:headURL>headURL</A> attribute.
+
+<DT><A NAME=d:headURL HREF=#a:headURL><STRONG>headURL</STRONG></A>
+<DD> If <B>headURL</B> is defined, it is
+ output as part of the head label of the edge.
+ Also, this value is used near the head node, overriding any
+ <A HREF=#d:URL>URL</A> value.
+ See <A HREF=#h:undir_note>limitation</A>.
+
+<DT><A NAME=d:height HREF=#a:height><STRONG>height</STRONG></A>
+<DD> Height of node, in inches. This is taken as the initial, minimum height
+ of the node. If <A HREF=#d:fixedsize><B>fixedsize</B></A> is true, this
+ will be the final height of the node. Otherwise, if the node label
+ requires more height to fit, the node's height will be increased to
+ contain the label. Note also that, if the output format is dot, the
+ value given to <B>height</B> will be the final value.
+
+<DT><A NAME=d:href HREF=#a:href><STRONG>href</STRONG></A>
+<DD> Synonym for <A HREF=#d:URL>URL</A>.
+
+<DT><A NAME=d:id HREF=#a:id><STRONG>id</STRONG></A>
+<DD> Allows the graph author to provide an id for graph objects which is to be included in the output.
+ Normal "N", "E", "G" substitutions are applied.
+ If provided, it is the reponsiblity of the provider to keep
+ its values sufficiently unique for its intended downstream use.
+ Note, in particular, that "E" does not provide a unique id for multi-edges.
+ If no id attribute is provided, then a unique internal id is used, however this value is unpredictable by the graph writer.
+ An externally provided id is not used internally.
+
+<DT><A NAME=d:image HREF=#a:image><STRONG>image</STRONG></A>
+<DD> Gives the name of a file containing an image to be displayed inside
+ a node. The image file must be in one of the recognized formats,
+ typically JPEG, PNG, GIF or Postscript, and be able to be converted
+ into the desired output format.
+ <P>
+ Unlike with the <A HREF=#d:shapefile>shapefile</A> attribute,
+ the image is treated as node
+ content rather than the entire node. In particular, an image can
+ be contained in a node of any shape, not just a rectangle.
+
+<DT><A NAME=d:imagescale HREF=#a:imagescale><STRONG>imagescale</STRONG></A>
+<DD> Attribute controlling how an image fills its
+ containing node. In general, the image is given its natural size,
+ (cf. <A HREF=#d:dpi>dpi</A>),
+ and the node size is made large enough to contain its image, its
+ label, its margin, and its peripheries.
+ Its width and height will also be at least as large as its
+ minimum <A HREF=#d:width>width</A> and <A HREF=#d:height>height</A>.
+ If, however, <TT>fixedsize=true</TT>,
+ the width and height attributes specify the exact size of the node.
+ <P>
+ During rendering, in the default case (<TT>imagescale=false</TT>),
+ the image retains its natural size.
+ If <TT>imagescale=true</TT>,
+ the image is uniformly scaled (i.e., its aspect ration is
+ preserved) to fit inside the node.
+ At least one dimension of the image will be as large as possible
+ given the size of the node.
+ When <TT>imagescale=width</TT>,
+ the width of the image is scaled to fill the node width.
+ The corresponding property holds when <TT>imagescale=height</TT>.
+ When <TT>imagescale=both</TT>,
+ both the height and the width are scaled separately to fill the node.
+ <P>
+ In all cases, if a dimension of the image is larger than the
+ corresponding dimension of the node, that dimension of the
+ image is scaled down to fit the node. As with the case of
+ expansion, if <TT>imagescale=true</TT>, width and height are
+ scaled uniformly.
+
+<DT><A NAME=d:K HREF=#a:K><STRONG>K</STRONG></A>
+<DD> Spring constant used in virtual physical model. It roughly corresponds
+ to an ideal edge length (in inches), in that increasing K tends to
+ increase the distance between nodes.
+ Note that the edge attribute <A HREF=#d:len>len</A> can be used to
+ override this value for adjacent nodes.
+
+<DT><A NAME=d:label HREF=#a:label><STRONG>label</STRONG></A>
+<DD> Text label attached to objects.
+ If a node's <A HREF=#d:shape>shape</A> is record, then the label can
+ have a <A HREF=shapes.html#record>special format</A>
+ which describes the record layout.
+
+<DT><A NAME=d:labelangle HREF=#a:labelangle><STRONG>labelangle</STRONG></A>
+<DD> This, along with <A HREF=#d:labeldistance>labeldistance</A>, determine
+ where the
+ headlabel (taillabel) are placed with respect to the head (tail)
+ in polar coordinates. The origin in the coordinate system is
+ the point where the edge touches the node. The ray of 0 degrees
+ goes from the origin back along the edge, parallel to the edge
+ at the origin.
+ <P>
+ The angle, in degrees, specifies the rotation from the 0 degree ray,
+ with positive angles moving counterclockwise and negative angles
+ moving clockwise.
+
+<DT><A NAME=d:labeldistance HREF=#a:labeldistance><STRONG>labeldistance</STRONG></A>
+<DD> Multiplicative scaling factor adjusting the distance that
+ the headlabel(taillabel) is from the head(tail) node.
+ The default distance is 10 points. See <A HREF=#d:labelangle>labelangle</A>
+ for more details.
+
+<DT><A NAME=d:labelfloat HREF=#a:labelfloat><STRONG>labelfloat</STRONG></A>
+<DD> If true, allows edge labels to be less constrained in position.
+ In particular, it may appear on top of other edges.
+
+<DT><A NAME=d:labelfontcolor HREF=#a:labelfontcolor><STRONG>labelfontcolor</STRONG></A>
+<DD> Color used for headlabel and taillabel.
+ If not set, defaults to edge's fontcolor.
+
+<DT><A NAME=d:labelfontname HREF=#a:labelfontname><STRONG>labelfontname</STRONG></A>
+<DD> Font used for headlabel and taillabel.
+ If not set, defaults to edge's fontname.
+
+<DT><A NAME=d:labelfontsize HREF=#a:labelfontsize><STRONG>labelfontsize</STRONG></A>
+<DD> Font size, <A HREF=#points>in points</A>, used for headlabel and taillabel.
+ If not set, defaults to edge's fontsize.
+
+<DT><A NAME=d:labelhref HREF=#a:labelhref><STRONG>labelhref</STRONG></A>
+<DD> Synonym for <A HREF=#d:labelURL>labelURL</A>.
+
+<DT><A NAME=d:labeljust HREF=#a:labeljust><STRONG>labeljust</STRONG></A>
+<DD> Justification for cluster labels. If "r", the label
+ is right-justified within bounding rectangle; if "l", left-justified;
+ else the label is centered.
+ Note that a subgraph inherits attributes from its parent. Thus, if
+ the root graph sets <B>labeljust</B> to "l", the subgraph inherits
+ this value.
+
+<DT><A NAME=d:labelloc HREF=#a:labelloc><STRONG>labelloc</STRONG></A>
+<DD> Top/bottom placement of graph and cluster labels.
+ If the attribute is "t", place label at the top;
+ if the attribute is "b", place label at the bottom.
+ By default, root
+ graph labels go on the bottom and cluster labels go on the top.
+ Note that a subgraph inherits attributes from its parent. Thus, if
+ the root graph sets <B>labelloc</B> to "b", the subgraph inherits
+ this value.
+
+<DT><A NAME=dd:labelloc HREF=#aa:labelloc><STRONG>labelloc</STRONG></A>
+<DD> Vertical placement of node label. By default, if the height of a node
+ is larger than the height of its label, the label is vertically centered.
+ If <TT>labelloc</TT> is set to "t", "c", or "b", the label is aligned
+ with the top, centered, or aligned with the bottom of the node, respectively.
+
+<DT><A NAME=d:labeltarget HREF=#a:labeltarget><STRONG>labeltarget</STRONG></A>
+<DD> If the edge has a <A HREF=#d:URL>URL</A> or <A HREF=#d:labelURL>labelURL</A>
+ attribute, this attribute determines which window of the
+ browser is used
+ for the URL attached to the label.
+ Setting it to "_graphviz" will open a new window if it
+ doesn't already exist, or reuse it if it does.
+ If undefined, the value of the <A HREF=#d:target>target</A> is used.
+
+<DT><A NAME=d:labeltooltip HREF=#a:labeltooltip><STRONG>labeltooltip</STRONG></A>
+<DD> Tooltip annotation attached to label of an edge.
+ This is used only if the edge has a <A HREF=#d:URL>URL</A>
+ or <A HREF=#d:labelURL>labelURL</A> attribute.
+
+<DT><A NAME=d:labelURL HREF=#a:labelURL><STRONG>labelURL</STRONG></A>
+<DD> If <B>labelURL</B> is defined, this is the link used for the label
+ of an edge. This value overrides any <A HREF=#d:URL>URL</A>
+ defined for the edge.
+
+<DT><A NAME=d:landscape HREF=#a:landscape><STRONG>landscape</STRONG></A>
+<DD> If true, the graph is rendered in landscape mode. Synonymous with
+ <A HREF=#d:rotate><TT>rotate=90</TT></A> or
+ <A HREF=#d:orientation><TT>orientation=landscape</TT></A>.
+
+<DT><A NAME=d:layer HREF=#a:layer><STRONG>layer</STRONG></A>
+<DD> Specifies layers in which the node or edge is present.
+
+<DT><A NAME=d:layers HREF=#a:layers><STRONG>layers</STRONG></A>
+<DD> Specifies a linearly ordered list of layer names attached to the graph
+ The graph is then output in separate layers. Only those components
+ belonging to the current output layer appear. For more information,
+ see the page <A HREF="http://www.graphviz.org/Documentation/html/layers/">How to use drawing layers (overlays)</A>.
+
+<DT><A NAME=d:layersep HREF=#a:layersep><STRONG>layersep</STRONG></A>
+<DD> Specifies the separator characters used to split the
+ <A HREF=#d:layers>layers </A>attribute into a list of layer names.
+
+<DT><A NAME=d:layout HREF=#a:layout><STRONG>layout</STRONG></A>
+<DD> Specifies the name of the layout algorithm to use, such as "dot"
+ or "neato". Normally, graphs should be kept independent of a type of
+ layout. In some cases, however, it can be convenient to embed the type
+ of layout desired within the graph. For example, a graph containing
+ position information from a layout might want to record what the
+ associated layout algorithm was.
+ <P>
+ This attribute takes precedence over
+ the <A HREF=command.html#minusK>-K flag</A>
+ or the actual command name used.
+
+<DT><A NAME=d:len HREF=#a:len><STRONG>len</STRONG></A>
+<DD> Preferred edge length, in inches.
+
+<DT><A NAME=d:levels HREF=#a:levels><STRONG>levels</STRONG></A>
+<DD> Number of levels allowed in the multilevel scheme.
+
+<DT><A NAME=d:levelsgap HREF=#a:levelsgap><STRONG>levelsgap</STRONG></A>
+<DD> Specifies strictness of level constraints in neato
+ when <TT><A HREF=#d:mode>mode</A>="ipsep" or "hier"</TT>.
+ Larger positive values mean stricter constraints, which demand more
+ separation between levels. On the other hand, negative values will relax
+ the constraints by allowing some overlap between the levels.
+
+<DT><A NAME=d:lhead HREF=#a:lhead><STRONG>lhead</STRONG></A>
+<DD> Logical head of an edge. When <A HREF=#d:compound><B>compound</B></A> is true,
+ if <B>lhead</B> is defined and is the name of a cluster containing
+ the real head,
+ the edge is clipped to the boundary of the cluster.
+ See <A HREF=#h:undir_note>limitation</A>.
+
+<DT><A NAME=d:lp HREF=#a:lp><STRONG>lp</STRONG></A>
+<DD> Label position, <A HREF=#points>in points</A>.
+ The position indicates the center of the label.
+
+<DT><A NAME=d:ltail HREF=#a:ltail><STRONG>ltail</STRONG></A>
+<DD> Logical tail of an edge. When <A HREF=#d:compound><B>compound</B></A> is true,
+ if <B>ltail</B> is defined and is the name of a cluster
+ containing the real tail,
+ the edge is clipped to the boundary of the cluster.
+ See <A HREF=#h:undir_note>limitation</A>.
+
+<DT><A NAME=d:margin HREF=#a:margin><STRONG>margin</STRONG></A>
+<DD> For graphs, this sets x and y margins of canvas, in inches. If the margin
+ is a single double, both margins are set equal to the given value.
+ <P>
+ Note that the margin is not part of the drawing but just empty space
+ left around the drawing. It basically corresponds to a translation of
+ drawing, as would be necessary to center a drawing on a page. Nothing
+ is actually drawn in the margin. To actually extend the background of
+ a drawing, see the <A HREF=#d:pad>pad</A> attribute.
+ <P>
+ For nodes, this attribute specifies space left around the node's label.
+ By default, the value is <TT>0.11,0.055</TT>.
+
+<DT><A NAME=d:maxiter HREF=#a:maxiter><STRONG>maxiter</STRONG></A>
+<DD> Sets the number of iterations used.
+
+<DT><A NAME=d:mclimit HREF=#a:mclimit><STRONG>mclimit</STRONG></A>
+<DD> Multiplicative scale factor used to alter the MinQuit (default = 8)
+ and MaxIter (default = 24) parameters used during crossing
+ minimization. These correspond to the
+ number of tries without improvement before quitting and the
+ maximum number of iterations in each pass.
+
+<DT><A NAME=d:mindist HREF=#a:mindist><STRONG>mindist</STRONG></A>
+<DD> Specifies the minimum separation between all nodes.
+
+<DT><A NAME=d:minlen HREF=#a:minlen><STRONG>minlen</STRONG></A>
+<DD> Minimum edge length (rank difference between head and tail).
+
+<DT><A NAME=d:mode HREF=#a:mode><STRONG>mode</STRONG></A>
+<DD> Technique for optimizing the layout. If <B>mode</B> is <TT>"major"</TT>,
+ neato uses stress majorization. If <B>mode</B> is <TT>"KK"</TT>,
+ neato uses a version of the gradient descent method. The only advantage
+ to the latter technique is that it is sometimes appreciably faster for
+ small (number of nodes < 100) graphs. A significant disadvantage is that
+ it may cycle.
+ <P>
+ There are two new, experimental modes in neato, "hier", which adds a top-down
+ directionality similar to the layout used in dot, and "ipsep", which
+ allows the graph to specify minimum vertical and horizontal distances
+ between nodes. (See the <A HREF=#d:sep>sep</A> attribute.)
+
+<DT><A NAME=d:model HREF=#a:model><STRONG>model</STRONG></A>
+<DD> This value specifies how the distance matrix is computed for the input
+ graph. The distance matrix specifies the ideal distance between every
+ pair of nodes. neato attemps to find a layout which best achieves
+ these distances. By default, it uses the length of the shortest path,
+ where the length of each edge is given by its <A HREF=#d:len>len</A>
+ attribute. If <B>model</B> is <TT>"circuit"</TT>, neato uses the
+ circuit resistance
+ model to compute the distances. This tends to emphasize clusters. If
+ <B>model</B> is <TT>"subset"</TT>, neato uses the subset model. This sets the
+ edge length to be the number of nodes that are neighbors of exactly one
+ of the end points, and then calculates the shortest paths. This helps
+ to separate nodes with high degree.
+
+<DT><A NAME=d:mosek HREF=#a:mosek><STRONG>mosek</STRONG></A>
+<DD> If Graphviz is built with MOSEK defined, mode=ipsep and mosek=true,
+ the Mosek software (www.mosek.com) is use to solve the ipsep constraints.
+
+<DT><A NAME=d:nodesep HREF=#a:nodesep><STRONG>nodesep</STRONG></A>
+<DD> Minimum space between two adjacent nodes in the same rank, in inches.
+
+<DT><A NAME=d:nojustify HREF=#a:nojustify><STRONG>nojustify</STRONG></A>
+<DD> By default, the justification of multi-line labels is done within the
+ largest context that makes sense. Thus, in the label of a polygonal
+ node, a left-justified line will align with the left side of the node
+ (shifted by the prescribed <A HREF=#d:margin>margin</A>).
+ In record nodes, left-justified
+ line will line up with the left side of the enclosing column of fields.
+ If <B>nojustify</B> is <TT>"true"</TT>, multi-line labels will be justified
+ in the context of itself. For example, if the attribute is set,
+ the first label line is long, and the second is shorter and left-justified,
+ the second will align with the left-most character in the first line,
+ regardless of how large the node might be.
+
+<DT><A NAME=d:normalize HREF=#a:normalize><STRONG>normalize</STRONG></A>
+<DD> If set, normalize coordinates of final
+ layout so that the first point is at the origin, and then rotate the
+ layout so that the first edge is horizontal.
+
+<DT><A NAME=d:nslimit HREF=#a:nslimit><STRONG>nslimit</STRONG></A>
+,<DT><A NAME=d:nslimit1 HREF=#a:nslimit1><STRONG>nslimit1</STRONG></A>
+<DD> Used to set number of iterations in
+ network simplex applications. <B>nslimit</B> is used in
+ computing node x coordinates, <B>nslimit1</B> for ranking nodes.
+ If defined, # iterations = <B>nslimit(1)</B> * # nodes;
+ otherwise, # iterations = MAXINT.
+
+<DT><A NAME=d:ordering HREF=#a:ordering><STRONG>ordering</STRONG></A>
+<DD> If "out" for a graph G, and n is a node in G, then edges n->* appear
+ left-to-right in the same order in which they are defined.
+ If "in", the edges *->n appear
+ left-to-right in the same order in which they are defined for all
+ nodes n.
+
+<DT><A NAME=d:orientation HREF=#a:orientation><STRONG>orientation</STRONG></A>
+<DD> Angle, in degrees, used to rotate node shapes.
+
+<DT><A NAME=dd:orientation HREF=#aa:orientation><STRONG>orientation</STRONG></A>
+<DD> If "[lL]*", set graph orientation to landscape
+ Used only if <A HREF=#d:rotate><B>rotate</B></A> is not defined.
+
+<DT><A NAME=d:outputorder HREF=#a:outputorder><STRONG>outputorder</STRONG></A>
+<DD> Specify order in which nodes and edges are drawn.
+
+<DT><A NAME=d:overlap HREF=#a:overlap><STRONG>overlap</STRONG></A>
+<DD> Determines if and how node overlaps should be removed. Nodes are first
+ enlarged using the <A HREF=#d:sep><B>sep</B></A> attribute.
+ If "true" , overlaps are retained.
+ If the value is "scale", overlaps are removed by uniformly scaling in x and y.
+ If the value converts to "false", node overlaps are removed by a
+ Voronoi-based technique.
+ If the value is "scalexy", x and y are separately
+ scaled to remove overlaps.
+ If the value is "orthoxy" or "orthoyx", overlaps
+ are moved by optimizing two constraint problems, one for the x axis and
+ one for the y. The suffix indicates which axis is processed first.
+ If the value is "ortho", the technique is similar to "orthoxy" except a
+ heuristic is used to reduce the bias between the two passes.
+ If the value is "ortho_yx", the technique is the same as "ortho", except
+ the roles of x and y are reversed.
+ The values "portho", "porthoxy", "porthoxy", and "portho_yx" are similar
+ to the previous four, except only pseudo-orthogonal ordering is
+ enforced.
+ <P>
+ If the value is "compress", the layout will be scaled down as much as
+ possible without introducing any overlaps, obviously assuming there are
+ none to begin with.
+ <P>
+ If the value is "vpsc", overlap removal is similarly to "ortho", except
+ quadratic optimization is used to minimize node displacement.
+ <P>
+ If the layout is done by neato with <A HREF=#d:mode>mode</A>="ipsep",
+ then one can use <TT>overlap=ipsep</TT>.
+ In this case, the overlap removal constraints are
+ incorporated into the layout algorithm itself.
+ N.B. At present, this only supports one level of clustering.
+ <P>
+ Except for fdp, the layouts assume <TT>overlap="true"</TT> as the default.
+ Fdp first uses a number of passes using built-in, force-directed technique
+ to remove overlaps. Thus, fdp accepts <B>overlap</B> with an integer
+ prefix followed by a colon, specifying the number of tries. If there is
+ no prefix, no initial tries will be performed. If there is nothing following
+ a colon, none of the above methods will be attempted. By default, fdp
+ uses <TT>overlap="9:portho"</TT>. Note that <TT>overlap="true"</TT>,
+ <TT>overlap="0:true"</TT> and <TT>overlap="0:"</TT> all turn off all overlap
+ removal.
+ <P>
+ Except for the Voronoi method, all of these transforms preserve the
+ orthogonal ordering of the original layout. That is, if the x coordinates
+ of two nodes are originally the same, they will remain the same, and if
+ the x coordinate of one node is originally less than the x coordinate of
+ another, this relation will still hold in the transformed layout. The
+ similar properties hold for the y coordinates.
+ This is not quite true for the "porth*" cases. For these, orthogonal
+ ordering is only preserved among nodes related by an edge.
+ <P>
+ <B>NOTE: </B>The methods "orthoxy" and "orthoyx" are still evolving. The
+ semantics of these may change, or these methods may disappear altogether.
+
+<DT><A NAME=d:pack HREF=#a:pack><STRONG>pack</STRONG></A>
+<DD> This is true if the value of pack is "true" (case-insensitive) or a
+ non-negative integer. If true, each connected component of the graph is
+ laid out separately, and then the graphs are packed tightly.
+ If pack has an integral value, this is used as the size,
+ in <A HREF=#points>points</A>, of
+ a margin around each part; otherwise, a default margin of 8 is used.
+ If pack is interpreted as false, the entire graph is laid out together.
+ The granularity and method of packing is influenced by the
+ <A HREF=#d:packmode>packmode</A> attribute.
+ <P>
+ For layouts which always do packing, such a twopi, the <B>pack</B>
+ attribute is just used to set the margin.
+
+<DT><A NAME=d:packmode HREF=#a:packmode><STRONG>packmode</STRONG></A>
+<DD> This indicates the granularity and method used for packing
+ (cf. <A HREF=#k:packMode>packMode</A>). Note that defining
+ <B>packmode</B> will automatically turn on packing as though one had
+ set <B>pack=true</B>.
+
+<DT><A NAME=d:pad HREF=#a:pad><STRONG>pad</STRONG></A>
+<DD> The pad attribute specifies how much, in inches, to extend the
+ drawing area around the minimal area needed to draw the graph.
+ If the pad is a single double, both the x and y pad values are set
+ equal to the given value. This area is part of the
+ drawing and will be filled with the background color, if appropriate.
+ <P>
+ Normally, a small pad is used for aesthetic reasons, especially when
+ a background color is used, to avoid having nodes and edges abutting
+ the boundary of the drawn region.
+
+<DT><A NAME=d:page HREF=#a:page><STRONG>page</STRONG></A>
+<DD> Width and height of output pages, in inches. If this is set and is
+ smaller than the size of the layout, a rectangular array of pages of
+ the specified page size is overlaid on the layout, with origins
+ aligned in the lower-left corner, thereby partitioning the layout
+ into pages. The pages are then produced one at a time, in
+ <A HREF=#d:pagedir>pagedir</A> order.
+ <P>
+ At present, this only works for PostScript output. For other types of
+ output, one should use another tool to split the output into multiple
+ output files. Or use the <A HREF=#d:viewport>viewport</A> to generate
+ multiple files.
+
+<DT><A NAME=d:pagedir HREF=#a:pagedir><STRONG>pagedir</STRONG></A>
+<DD> If the <A HREF=#d:page>page</A> attribute is set and applicable,
+ this attribute specifies the order in which the pages are emitted.
+ This is limited to one of the 8 row or column major orders.
+
+<DT><A NAME=d:pencolor HREF=#a:pencolor><STRONG>pencolor</STRONG></A>
+<DD> Color used to draw the bounding box around a cluster.
+ If <B>pencolor</B> is not defined, <A HREF=#d:color><B>color</B></A> is
+ used. If this is not defined, <A HREF=#d:bgcolor>bgcolor</A> is used.
+ If this is not defined, the default is used.
+ <P>
+ Note that a cluster inherits the root graph's attributes if defined.
+ Thus, if the root graph has defined a <B>pencolor</B>, this will override a
+ <B>color</B> or <B>bgcolor</B> attribute set for the cluster.
+
+<DT><A NAME=d:penwidth HREF=#a:penwidth><STRONG>penwidth</STRONG></A>
+<DD> Specifies the width of the pen, in points, used to draw lines and curves,
+ including the boundaries of edges and clusters. The value is inherited
+ by subclusters.
+ It has no effect on text.
+ <P>
+ Previous to 31 January 2008, the effect of <TT>penwidth=<I>W</I></TT>
+ was achieved by including <TT>setlinewidth(<I>W</I>)</TT>
+ as part of a <A HREF=#d:style><TT>style</TT></A> specification.
+ If both are used, <TT>penwidth</TT> will be used.
+
+<DT><A NAME=d:peripheries HREF=#a:peripheries><STRONG>peripheries</STRONG></A>
+<DD> Set number of peripheries used in polygonal shapes and cluster
+ boundaries. Note that
+ <A HREF=shapes.html#epsf>user-defined shapes</A> are treated as a
+ form of box shape, so the default
+ peripheries value is 1 and the user-defined shape will be drawn in
+ a bounding rectangle. Setting <TT>peripheries=0</TT> will turn this off.
+ Also, 1 is the maximum peripheries value for clusters.
+
+<DT><A NAME=d:pin HREF=#a:pin><STRONG>pin</STRONG></A>
+<DD> If true and the node has a pos attribute on input, neato prevents the
+ node from moving from the input position. This property can also be specified
+ in the pos attribute itself (cf. the <A HREF=#d:point>point</A> type).
+ <P>
+ <B>Note:</B> Due to an artifact of the implementation, final coordinates
+ are translated to the origin. Thus, if you look at the output coordinates
+ given in the (x)dot or plain format, pinned nodes will not have the same
+ output coordinates as were given on input. If this is important, a
+ simple workaround is to maintain the coordinates of a pinned node. The vector
+ difference between the old and new coordinates will give the translation,
+ which can then be subtracted from all of the appropriate coordinates.
+
+<DT><A NAME=d:pos HREF=#a:pos><STRONG>pos</STRONG></A>
+<DD> Position of node, or spline control points.
+ For nodes, the position indicates the center of the node.
+ On output, the coordinates are in <A HREF=#points>points</A>.
+ <P>
+ In neato, fdp and sfdp, pos can be used to set the initial position of a node.
+ By default, the coordinates are assumed to be in points. However, the
+ <A HREF=command.html#d:s>-s</A> command line flag can be used to specify
+ different units.
+ <P>
+ When the <A HREF=command.html#d:n>-n</A> command line flag is used with
+ neato, it is assumed the positions have been set by one of the layout
+ programs, and are therefore in points. Thus, <TT>neato -n</TT> can accept
+ input correctly without requiring a <TT>-s</TT> flag and, in fact,
+ ignores any such flag.
+
+<DT><A NAME=d:quadtree HREF=#a:quadtree><STRONG>quadtree</STRONG></A>
+<DD> Quadtree scheme to use.
+ <P>
+ A TRUE bool value corresponds to "normal";
+ a FALSE bool value corresponds to "none".
+ As a slight exception to the normal interpretation of bool,
+ a value of "2" corresponds to "fast".
+
+<DT><A NAME=d:quantum HREF=#a:quantum><STRONG>quantum</STRONG></A>
+<DD> If <B>quantum</B> > 0.0, node label dimensions
+ will be rounded to integral multiples of the quantum.
+
+<DT><A NAME=d:rank HREF=#a:rank><STRONG>rank</STRONG></A>
+<DD> Rank constraints on the nodes in a subgraph.
+ If <B>rank</B>="same", all nodes are placed on the same rank.
+ If <B>rank</B>="min", all nodes are placed on the minimum rank.
+ If <B>rank</B>="source", all nodes are placed on the minimum rank, and
+ the only nodes on the minimum rank belong to some subgraph whose
+ rank attribute is "source" or "min".
+ Analogous criteria hold for <B>rank</B>="max" and <B>rank</B>="sink".
+ (Note: the
+ minimum rank is topmost or leftmost, and the maximum rank is bottommost
+ or rightmost.)
+
+<DT><A NAME=d:rankdir HREF=#a:rankdir><STRONG>rankdir</STRONG></A>
+<DD> Sets direction of graph layout. For example, if <B>rankdir</B>="LR",
+ and barring cycles, an edge <CODE>T -> H;</CODE> will go
+ from left to right. By default, graphs are laid out from top to bottom.
+ <P>
+ This attribute also has a side-effect in determining how record nodes
+ are interpreted. See <A HREF="shapes.html#record">record shapes</A>.
+
+<DT><A NAME=d:ranksep HREF=#a:ranksep><STRONG>ranksep</STRONG></A>
+<DD> In dot, this gives the desired rank separation, in inches. This is
+ the minimum vertical distance between the bottom of the nodes in one
+ rank and the tops of nodes in the next. If the value
+ contains "equally", the centers of all ranks are spaced equally apart.
+ Note that both
+ settings are possible, e.g., ranksep = "1.2 equally".
+ In twopi, specifies radial separation of concentric circles.
+
+<DT><A NAME=d:ratio HREF=#a:ratio><STRONG>ratio</STRONG></A>
+<DD> Sets the aspect ratio (drawing height/drawing width) for the drawing.
+ Note that this is adjusted before
+ the <A HREF=#d:size><B>size</B></A> attribute constraints are enforced.
+ <P>
+ If <B>ratio</B> is numeric, it is taken as the desired aspect ratio.
+ Then, if the actual aspect ratio is less than the desired ratio,
+ the drawing height is scaled up to achieve the
+ desired ratio; if the actual ratio is greater than that desired ratio,
+ the drawing width is scaled up.
+ <P>
+ If <B>ratio</B> = "fill" and the <A HREF=#d:size><B>size</B></A>
+ attribute is set, node positions are scaled, separately in both x
+ and y, so that the final drawing exactly fills the specified size.
+ <P>
+ If <B>ratio</B> = "compress" and the <A HREF=#d:size><B>size</B></A>
+ attribute is set, dot attempts to compress the initial layout to fit
+ in the given size. This achieves a tighter packing of nodes but
+ reduces the balance and symmetry. This feature only works in dot.
+ <P>
+ If <B>ratio</B> = "expand", the <A HREF=#d:size><B>size</B></A>
+ attribute is set, and both the width and the height of the graph are
+ less than the value in <A HREF=#d:size><B>size</B></A>, node positions are scaled
+ uniformly until at least
+ one dimension fits <A HREF=#d:size><B>size</B></A> exactly.
+ Note that this is distinct from using <A HREF=#d:size><B>size</B></A> as the
+ desired size, as here the drawing is expanded before edges are generated and
+ all node and text sizes remain unchanged.
+ <P>
+ If <B>ratio</B> = "auto", the <A HREF=#d:page><B>page</B></A>
+ attribute is set and the graph cannot be drawn on a single page,
+ then <A HREF=#d:size><B>size</B></A> is set to an ``ideal'' value.
+ In particular, the size in a given dimension will be the smallest integral
+ multiple of the page size in that dimension which is at least half the
+ current size. The two dimensions are then scaled independently to the
+ new size. This feature only works in dot.
+
+<DT><A NAME=d:rects HREF=#a:rects><STRONG>rects</STRONG></A>
+<DD> Rectangles for fields of records, <A HREF=#points>in points</A>.
+
+<DT><A NAME=d:regular HREF=#a:regular><STRONG>regular</STRONG></A>
+<DD> If true, force polygon to be regular.
+
+<DT><A NAME=d:remincross HREF=#a:remincross><STRONG>remincross</STRONG></A>
+<DD> If true and there are multiple clusters, run cross
+ minimization a second time.
+
+<DT><A NAME=d:repulsiveforce HREF=#a:repulsiveforce><STRONG>repulsiveforce</STRONG></A>
+<DD> The power of the repulsive force used in an extended Fruchterman-Reingold
+ force directed model. Values larger than 1 tend to reduce
+ the warping effect at the expense of less clustering.
+
+<DT><A NAME=d:resolution HREF=#a:resolution><STRONG>resolution</STRONG></A>
+<DD> This is a synonym for the <A HREF=#d:dpi>dpi</A> attribute.
+
+<DT><A NAME=d:root HREF=#a:root><STRONG>root</STRONG></A>
+<DD> This specifies nodes to be used as the center of the
+ layout and the root of the generated spanning tree. As a graph attribute,
+ this gives the name of the node. As a node attribute (circo only), it
+ specifies that the node should be used as a central node. In twopi,
+ this will actually be the central node. In circo, the block containing
+ the node will be central in the drawing of its connected component.
+ If not defined,
+ twopi will pick a most central node, and circo will pick a random node.
+
+<DT><A NAME=d:rotate HREF=#a:rotate><STRONG>rotate</STRONG></A>
+<DD> If 90, set drawing orientation to landscape.
+
+<DT><A NAME=d:samehead HREF=#a:samehead><STRONG>samehead</STRONG></A>
+<DD> Edges with the same head and the same <B>samehead</B> value are aimed
+ at the same point on the head.
+ See <A HREF=#h:undir_note>limitation</A>.
+
+<DT><A NAME=d:sametail HREF=#a:sametail><STRONG>sametail</STRONG></A>
+<DD> Edges with the same tail and the same <B>sametail</B> value are aimed
+ at the same point on the tail.
+ See <A HREF=#h:undir_note>limitation</A>.
+
+<DT><A NAME=d:samplepoints HREF=#a:samplepoints><STRONG>samplepoints</STRONG></A>
+<DD> If the input graph defines the <A HREF=#d:vertices><B>vertices</B></A>
+ attribute, and output is dot or xdot, this gives
+ the number of points used for a node whose shape is a circle or ellipse.
+ It plays the same role in neato, when adjusting the layout to avoid
+ overlapping nodes, and in image maps.
+
+<DT><A NAME=d:searchsize HREF=#a:searchsize><STRONG>searchsize</STRONG></A>
+<DD> During network simplex, maximum number of edges with negative cut values
+ to search when looking for one with minimum cut value.
+
+<DT><A NAME=d:sep HREF=#a:sep><STRONG>sep</STRONG></A>
+<DD> Specifies margin to leave around nodes when removing node overlap.
+ This guarantees a minimal non-zero distance between nodes.
+ <P>
+ If the attribute begins with a plus sign '+', an additive margin is
+ specified. That is, "+w,h" causes the node's bounding box to be increased
+ by w
+ points on the left and right sides, and by h points on the top and bottom.
+ Without a plus sign, the node is scaled by 1 + w in the x coordinate
+ and 1 + h in the y coordinate.
+ <P>
+ If only a single number is given, this is used for both dimensions.
+ <P>
+ If unset but <A HREF=#d:esep>esep</A> is defined, the <tt>sep</tt> values
+ will be set to the <tt>esep</tt> values divided by <tt>0.8</tt>.
+ If <tt>esep</tt> is unset, the default value is used.
+
+<DT><A NAME=d:shape HREF=#a:shape><STRONG>shape</STRONG></A>
+<DD> Set the shape of a node.
+
+<DT><A NAME=d:shapefile HREF=#a:shapefile><STRONG>shapefile</STRONG></A>
+<DD> (Deprecated) If defined, shapefile specifies a file containing user-supplied node content.
+ The <A HREF=#d:shape><B>shape</B></A> of the node is set to box.
+ The image in the shapefile must be
+ rectangular. The image formats supported as well as the precise semantics of
+ how the file is used depends on the
+ <A HREF="http://www.graphviz.org/doc/info/output.html">output format</A>. For further details, see
+ <A HREF=http://www.graphviz.org/Documentation/html/shapehowto.html#ext_image>External PostScript files</A>.
+ <P>
+ There is one exception to this usage.
+ If <B>shape</B> is set to "epsf", shapefile gives
+ a filename containing a definition of the node in PostScript.
+ The graphics defined must be contain all of the
+ node content, including any desired boundaries.
+ For further details, see
+ <A HREF=http://www.graphviz.org/Documentation/html/shapehowto.html#ext_ps>
+ External PostScript files</A>.
+
+<DT><A NAME=d:showboxes HREF=#a:showboxes><STRONG>showboxes</STRONG></A>
+<DD> Print guide boxes in PostScript at the beginning of
+ routesplines if 1, or at the end if 2. (Debugging)
+
+<DT><A NAME=d:sides HREF=#a:sides><STRONG>sides</STRONG></A>
+<DD> Number of sides if <A HREF=#d:shape><B>shape</B></A>=polygon.
+
+<DT><A NAME=d:size HREF=#a:size><STRONG>size</STRONG></A>
+<DD> Maximum width and height of drawing, in inches.
+ If defined and the drawing is too large, the drawing is uniformly
+ scaled down so that it fits within the given size.
+ <P>
+ If <TT>size</TT> ends in an exclamation point (<TT>!</TT>),
+ then it is taken to be
+ the desired size. In this case, if both dimensions of the drawing are
+ less than <TT>size</TT>, the drawing is scaled up uniformly until at
+ least one dimension equals its dimension in <TT>size</TT>.
+ <P>
+ Note that there is some interaction between the <B>size</B> and
+ <A HREF=#d:ratio><B>ratio</B></A> attributes.
+
+<DT><A NAME=d:skew HREF=#a:skew><STRONG>skew</STRONG></A>
+<DD> Skew factor for <A HREF=#d:shape><B>shape</B></A>=polygon. Positive values
+ skew top of polygon to right; negative to left.
+
+<DT><A NAME=d:smoothing HREF=#a:smoothing><STRONG>smoothing</STRONG></A>
+<DD> Specifies a post-processing step used to smooth out an uneven distribution
+ of nodes.
+
+<DT><A NAME=d:splines HREF=#a:splines><STRONG>splines</STRONG></A>
+<DD> Controls how, and if, edges are represented. If true, edges are drawn as
+ splines routed around nodes; if false, edges are drawn as line segments.
+ If set to "", no edges are drawn at all.
+ <P>
+ (1 March 2007) The values <TT>line</TT> and <TT>spline</TT> can be
+ used as synonyms for <TT>false</TT> and <TT>true</TT>, respectively.
+ In addition, the value <TT>polyline</TT> specifies that edges should be
+ drawn as polylines.
+ <P>
+ By default, the attribute is unset. How this is interpreted depends on
+ the layout. For dot, the default is to draw edges as splines. For all
+ other layouts, the default is to draw edges as line segments. Note that
+ for these latter layouts, if <TT>splines="true"</TT>, this
+ requires non-overlapping nodes (cf. <A HREF=#d:overlap><B>overlap</B></A>).
+ If fdp is used for layout and <TT>splines="compound"</TT>, then the edges are
+ drawn to avoid clusters as well as nodes.
+
+<DT><A NAME=d:start HREF=#a:start><STRONG>start</STRONG></A>
+<DD> Parameter used to determine the initial layout of nodes. If unset, the
+ nodes are randomly placed in a unit square with
+ the same seed is always used for the random number generator, so the
+ initial placement is repeatable.
+
+<DT><A NAME=d:style HREF=#a:style><STRONG>style</STRONG></A>
+<DD> Set style for node or edge. For cluster subgraph, if "filled", the
+ cluster box's background is filled.
+
+<DT><A NAME=d:stylesheet HREF=#a:stylesheet><STRONG>stylesheet</STRONG></A>
+<DD> A URL or pathname specifying an XML style sheet, used in SVG output.
+
+<DT><A NAME=d:tailclip HREF=#a:tailclip><STRONG>tailclip</STRONG></A>
+<DD> If true, the tail of an edge is clipped to the boundary of the tail node;
+ otherwise, the end of the edge goes to the center of the node, or the
+ center of a port, if applicable.
+
+<DT><A NAME=d:tailhref HREF=#a:tailhref><STRONG>tailhref</STRONG></A>
+<DD> Synonym for <A HREF=#d:tailURL>tailURL</A>.
+
+<DT><A NAME=d:taillabel HREF=#a:taillabel><STRONG>taillabel</STRONG></A>
+<DD> Text label to be placed near tail of edge.
+ See <A HREF=#h:undir_note>limitation</A>.
+
+<DT><A NAME=d:tailport HREF=#a:tailport><STRONG>tailport</STRONG></A>
+<DD> Indicates where on the tail node to attach the tail of the edge.
+ See <A HREF=#h:undir_note>limitation</A>.
+
+<DT><A NAME=d:tailtarget HREF=#a:tailtarget><STRONG>tailtarget</STRONG></A>
+<DD> If the edge has a <A HREF=#d:tailURL>tailURL</A>,
+ this attribute determines which window of the
+ browser is used
+ for the URL. Setting it to "_graphviz" will open a new window if it
+ doesn't already exist, or reuse it if it does.
+ If undefined, the value of the <A HREF=#d:target>target</A> is used.
+
+<DT><A NAME=d:tailtooltip HREF=#a:tailtooltip><STRONG>tailtooltip</STRONG></A>
+<DD> Tooltip annotation attached to the tail of an edge. This is used only
+ if the edge has a <A HREF=#d:tailURL>tailURL</A> attribute.
+
+<DT><A NAME=d:tailURL HREF=#a:tailURL><STRONG>tailURL</STRONG></A>
+<DD> If <B>tailURL</B> is defined, it is
+ output as part of the tail label of the edge.
+ Also, this value is used near the tail node, overriding any
+ <A HREF=#d:URL>URL</A> value.
+ See <A HREF=#h:undir_note>limitation</A>.
+
+<DT><A NAME=d:target HREF=#a:target><STRONG>target</STRONG></A>
+<DD> If the object has a URL, this attribute determines which window
+ of the browser is used for the URL.
+ See <A HREF="http://www.w3.org/TR/html401/present/frames.html#adef-target">W3C documentation</A>.
+
+<DT><A NAME=d:tooltip HREF=#a:tooltip><STRONG>tooltip</STRONG></A>
+<DD> Tooltip annotation attached to the node or edge. If unset, Graphviz
+ will use the object's <A HREF=#d:label>label</A> if defined.
+ Note that if the label is a record specification or an HTML-like
+ label, the resulting tooltip may be unhelpful. In this case, if
+ tooltips will be generated, the user should set a <TT>tooltip</TT>
+ attribute explicitly.
+
+<DT><A NAME=d:truecolor HREF=#a:truecolor><STRONG>truecolor</STRONG></A>
+<DD> If set explicitly to true or false, the value determines whether or not
+ internal bitmap rendering relies on a truecolor color model or uses
+ a color palette.
+ If the attribute is unset, truecolor is not used
+ unless there is a <A HREF=#d:shapefile>shapefile</A> property
+ for some node in the graph.
+ The output model will use the input model when possible.
+ <P>
+ Use of color palettes results in less memory usage during creation of the
+ bitmaps and smaller output files.
+ <P>
+ Usually, the only time it is necessary to specify the truetype model
+ is if the graph uses more than 256 colors.
+ However, if one uses <A HREF=#d:bgcolor>bgcolor</A>=transparent with
+ a color palette, font
+ antialiasing can show up as a fuzzy white area around characters.
+ Using <B>truecolor</B>=true avoids this problem.
+
+<DT><A NAME=d:URL HREF=#a:URL><STRONG>URL</STRONG></A>
+<DD> Hyperlinks incorporated into device-dependent output.
+ At present, used in ps2, cmap, i*map and svg formats.
+ For all these formats, URLs can be attached to nodes, edges and
+ clusters. URL attributes can also be attached to the root graph in ps2,
+ cmap and i*map formats. This serves as the base URL for relative URLs in the
+ former, and as the default image map file in the latter.
+ <P>
+ For svg, cmapx and imap output, the active area for a node is its
+ visible image.
+ For example, an unfilled
+ node with no drawn boundary will only be active on its label.
+ For other output, the active area is its bounding box.
+ The active area for a cluster is its bounding box.
+ For edges, the active areas are small circles where the edge contacts its head
+ and tail nodes. In addition, for svg, cmapx and imap, the active area
+ includes a thin polygon approximating the edge. The circles may
+ overlap the related node, and the edge URL dominates.
+ If the edge has a label, this will also be active.
+ Finally, if the edge has a head or tail label, this will also be active.
+ <P>
+ Note that, for edges, the attributes <A HREF=#d:headURL>headURL</A>,
+ <A HREF=#d:tailURL>tailURL</A>, <A HREF=#d:labelURL>labelURL</A> and
+ <A HREF=#d:edgeURL>edgeURL</A> allow control of various parts of an
+ edge.
+ Also note that, if active areas of two edges overlap, it is unspecified
+ which area dominates.
+
+<DT><A NAME=d:vertices HREF=#a:vertices><STRONG>vertices</STRONG></A>
+<DD> If the input graph defines this attribute, the node is polygonal,
+ and output is dot or xdot, this attribute provides the
+ coordinates of the vertices of the node's polygon, in inches.
+ If the node is an ellipse or circle, the
+ <A HREF=#d:samplepoints>samplepoints</A> attribute affects
+ the output.
+
+<DT><A NAME=d:viewport HREF=#a:viewport><STRONG>viewport</STRONG></A>
+<DD> Clipping window on final drawing.
+
+<DT><A NAME=d:voro_margin HREF=#a:voro_margin><STRONG>voro_margin</STRONG></A>
+<DD> Factor to scale up drawing to allow margin for expansion in
+ Voronoi technique. dim' = (1+2*margin)*dim.
+
+<DT><A NAME=d:weight HREF=#a:weight><STRONG>weight</STRONG></A>
+<DD> Weight of edge. In dot, the heavier the weight, the shorter,
+ straighter and more vertical the edge is.
+
+<DT><A NAME=d:width HREF=#a:width><STRONG>width</STRONG></A>
+<DD> Width of node, in inches. This is taken as the initial, minimum width
+ of the node. If <A HREF=#d:fixedsize><B>fixedsize</B></A> is true, this
+ will be the final width of the node. Otherwise, if the node label
+ requires more width to fit, the node's width will be increased to
+ contain the label. Note also that, if the output format is dot, the
+ value given to <B>width</B> will be the final value.
+
+<DT><A NAME=d:z HREF=#a:z><STRONG>z</STRONG></A>
+<DD> <B>Deprecated:</B>Use <A HREF=#d:pos><B>pos</B></A> attribute, along
+ with <A HREF=#d:dimen><B>dimen</B></A> and/or <A HREF=#d:dim><B>dim</B></A>
+ to specify dimensions.
+ <P>
+ Provides z coordinate value for 3D layouts and displays. If the
+ graph has <A HREF=#d:dim><B>dim</B></A> set to 3 (or more),
+ neato will use a node's <B>z</B> value
+ for the z coordinate of its initial position if
+ its <A HREF=#d:pos><B>pos</B></A> attribute is also defined.
+ <P>
+ Even if no <B>z</B> values are specified in the input, it is necessary to
+ declare a <B>z</B> attribute for nodes, e.g, using <TT>node[z=""]</TT>
+ in order to get z values on output.
+ Thus, setting <TT>dim=3</TT> but not declaring <B>z</B> will
+ cause <TT>neato -Tvrml</TT> to
+ layout the graph in 3D but project the layout onto the xy-plane
+ for the rendering. If the <B>z</B> attribute is declared, the final rendering
+ will be in 3D.
+
+</DL>
+<HR>
+<H1>Attribute Type Descriptions</H1>
+The following list gives the legal strings corresponding to values of
+the given types.
+<DL>
+<DT><A NAME=k:arrowType><STRONG>arrowType</STRONG></A>
+<DD><TABLE>
+ <TR><TD>"normal"<TD><IMG SRC="a_normal.gif">
+ <TD>"inv"<TD><IMG SRC="a_inv.gif"></TR>
+ <TR><TD>"dot"<TD><IMG SRC="a_dot.gif">
+ <TD>"invdot"<TD><IMG SRC="a_invdot.gif"></TR>
+ <TR><TD>"odot"<TD><IMG SRC="a_odot.gif">
+ <TD>"invodot"<TD><IMG SRC="a_invodot.gif"></TR>
+ <TR><TD>"none"<TD><IMG SRC="a_none.gif">
+ <TD>"tee"<TD><IMG SRC="a_tee.gif"></TR>
+ <TR><TD>"empty"<TD><IMG SRC="a_empty.gif">
+ <TD>"invempty"<TD><IMG SRC="a_invempty.gif"></TR>
+ <TR><TD>"diamond"<TD><IMG SRC="a_diamond.gif">
+ <TD>"odiamond"<TD><IMG SRC="a_odiamond.gif"></TR>
+ <TR><TD>"ediamond"<TD><IMG SRC="a_ediamond.gif">
+ <TD>"crow"<TD><IMG SRC="a_crow.gif"></TR>
+ <TR><TD>"box"<TD><IMG SRC="a_box.gif">
+ <TD>"obox"<TD><IMG SRC="a_obox.gif"></TR>
+ <TR><TD>"open"<TD><IMG SRC="a_open.gif">
+ <TD>"halfopen"<TD><IMG SRC="a_halfopen.gif"></TR>
+ <TR><TD>"vee"<TD><IMG SRC="a_open.gif">
+ </TABLE>
+ <P>
+ These are the basic set of backward-compatible arrow shapes. In addition,
+ there is a grammar of <A HREF=arrows.html>arrow shapes</A>
+ which can be used to describe a collection of 1,544,761 arrow combinations of the 36 varations of the primitive set of 9 arrows. The basic arrows shown
+ above contain all of the primitive shapes
+ (<TT>box</TT>, <TT>crow</TT>, <TT>diamond</TT>,
+ <TT>dot</TT>, <TT>inv</TT>, <TT>none</tt>,
+ <TT>normal</tt>, <TT>tee</TT>, <TT>vee</TT>)
+ plus ones that can be derived from the grammar
+ (<TT>odot</TT>, <TT>invdot</TT>, <TT>invodot</TT>,
+ <TT>obox</TT>, <TT>odiamond</TT>)
+ plus some supported as special cases for backward-compatibility
+ (<TT>ediamond</TT>, <TT>open</TT>, <TT>halfopen</TT>,
+ <TT>empty</TT>, <TT>invempty</TT>).
+
+<DT><A NAME=k:clusterMode><STRONG>clusterMode</STRONG></A>
+<DD>"local","global","none"
+
+<DT><A NAME=k:color><STRONG>color</STRONG></A>
+<DD>Colors can be specified using one of four formats.
+ <TABLE><TR><TD>"#%2x%2x%2x"<TD>Red-Green-Blue (RGB)</TR>
+ <TR><TD>"#%2x%2x%2x%2x"<TD>Red-Green-Blue-Alpha (RGBA)</TR>
+ <TR><TD>H[, ]+S[, ]+V<TD>Hue-Saturation-Value (HSV) 0.0 <= H,S,V <= 1.0</TR>
+ <TR><TD>string<TD><A HREF=colors.html>color name</A></TR></TABLE>
+ The specification for the RGB and RGBA formats are the format strings used by
+ <TT>sscanf</TT> to scan the color value. Thus, these values have the form
+ "#RGB" or "#RGBA", where R, G, B, and A each consist of 2 hexidecimal
+ digits, and can be separated by whitespace. HSV colors have the form of 3
+ numbers between 0 and 1, separated by whitespace or commas.
+ <P>
+ String-valued color specifications are case-insensitive and interpreted
+ in the context of the current color scheme, as specified by the
+ <A HREF=#d:colorscheme>colorscheme</A> attribute. If this is undefined,
+ the X11 naming scheme will be used.
+ An initial <TT>"/"</TT> character can be used to override the use of
+ the <TT>colorscheme</TT> attribute. In particular, a single initial
+ <TT>"/"</TT> will cause the string to be evaluated using the default
+ X11 naming. If the color value has the form <TT>"/ssss/yyyy"</TT>,
+ the name <TT>yyyy</TT> is interpreted using the schema <TT>ssss</TT>.
+ If the color scheme name is empty, i.e., the color has the
+ form <TT>"//yyyy"</TT>, the <TT>colorscheme</TT> attribute is used.
+ Thus, the forms <TT>"yyyy"</TT> and <TT>"//yyyy"</TT> are
+ equivalent.
+ <P>At present, Graphviz recognizes the default color scheme <TT>X11</TT>,
+ and the <A HREF="http://www.personal.psu.edu/faculty/c/a/cab38/ColorBrewer/ColorBrewer_intro.html">Brewer color schemes</A>. Please note that Brewer
+ color schemes are covered by this <A HREF=colors.html#brewer_license>license</A>.
+ <P>
+ Examples:<BR>
+ <TABLE border=1>
+ <TR><TH>Color<TH>RGB<TH>HSV<TH>String</TR>
+ <TR><TD align=center bgcolor=#ffffff>White<TD>"#ffffff"<TD>"0.000 0.000 1.000"<TD>"white"</TR>
+ <TR><TD align=center bgcolor=#000000><font color=white>Black</font><TD>"#000000"<TD>"0.000 0.000 0.000"<TD>"black"</TR>
+ <TR><TD align=center bgcolor=#ff0000>Red<TD>"#ff0000"<TD>"0.000 1.000 1.000"<TD>"red"</TR>
+ <TR><TD align=center bgcolor=#40e0d0>Turquoise<TD>"#40e0d0"<TD>"0.482 0.714 0.878"<TD>"turquoise"</TR>
+ <TR><TD align=center bgcolor=#a0522d>Sienna<TD>"#a0522d"<TD>"0.051 0.718 0.627"<TD>"sienna"</TR>
+ </TABLE>
+ <P>
+ Note that some output formats, e.g., <A HREF="output.html#a:mif">mif</A>,
+ only support a limited number of specific colors.
+ <P>
+ The string value <TT>transparent</TT> can be used to indicate no color.
+ This is only available in the output formats
+ ps, svg, fig, vmrl, and the bitmap formats. It can be used whenever a
+ color is needed but is most useful with
+ the <A HREF=#d:bgcolor>bgcolor</A> attribute.
+ Usually, the same effect can be achieved by setting
+ <A HREF=#d:style>style</A> to <TT>invis</TT>.
+
+<DT><A NAME=k:colorList><STRONG>colorList</STRONG></A>
+<DD>A colon-separated list of color values: <I>C</I>(:<I>C</I>)*
+ where each <I>C</I> is a <A HREF=#k:color>color</A> value.
+
+<DT><A NAME=k:dirType><STRONG>dirType</STRONG></A>
+<DD>For an edge <CODE>T -> H;</CODE>
+ <TABLE>
+ <TR><TD>"forward"<TD><IMG SRC="forward.gif">
+ <TD>"back"<TD><IMG SRC="back.gif"></TR>
+ <TR><TD>"both"<TD><IMG SRC="both.gif">
+ <TD>"none"<TD><IMG SRC="nohead.gif"></TR>
+ </TABLE>
+ For undirected edges <CODE>T -- H;</CODE>, one of the nodes, usually
+ the righthand one, is treated as the head for the purpose of
+ interpreting "forward" and "back".
+
+<DT><A NAME=k:escString><STRONG>escString</STRONG></A>
+<DD>string allowing escape sequences which are replaced according
+ to the context.
+ For node attributes, the substring "\N" is replaced by the name of the node,
+ and the substring "\G" by the name of the graph.
+ For graph or cluster attributes, the substring "\G" is replaced by the
+ name of the graph or cluster.
+ For edge attributes, the substring "\E" is replaced by the name of the edge,
+ the substring "\G" is replaced by the name of the graph or cluster,
+ and the substrings "\T" and "\H" by the names of
+ the tail and head nodes, respectively.
+ The name of an edge is the string formed from the name of the
+ tail node, the appropriate edge operator ("--" or "->") and the name of the
+ head node.
+ In all cases, the substring "\L" is replaced by the object's label attribute.
+ <P>
+ In addition, if the associated attribute is
+ <A HREF=#a:label>label</A>,
+ <A HREF=#a:headlabel>headlabel</A> or <A HREF=#a:taillabel>taillabel</A>,
+ the escape sequences "\n", "\l" and "\r"
+ divide the label into lines, centered, left-justified, and right-justified,
+ respectively.
+
+<DT><A NAME=k:layerList><STRONG>layerList</STRONG></A>
+<DD>list of strings separated by characters from the
+ <A HREF=#a:layersep>layersep</A> attribute (by default, colons,
+ tabs or spaces), defining <A HREF=#a:layer>layer</A>
+ names and implicitly numbered 1,2,...
+
+<DT><A NAME=k:layerRange><STRONG>layerRange</STRONG></A>
+<DD>layerId or layerId<B>s</B>layerId,<BR> where layerId = "all",
+ a decimal integer or a <A HREF=#a:layer>layer</A> name.
+ (An integer i corresponds to layer i.)
+ The string <B>s</B> consists of 1 or more separator characters specified
+ by the <A HREF=#a:layersep>layersep</A> attribute.
+
+<DT><A NAME=k:lblString><STRONG>lblString</STRONG></A>
+<DD>an <A HREF=#k:escString>escString</A>
+ or an <A HREF=shapes.html#html>HTML label</A>.
+
+<DT><A NAME=k:outputMode><STRONG>outputMode</STRONG></A>
+<DD>"breadthfirst","nodesfirst","edgesfirst"
+ These specify the order in which nodes and edges are drawn in concrete
+ output. The default "breadthfirst" is the simplest, but when the graph
+ layout does not avoid edge-node overlap, this mode will sometimes have
+ edges drawn over nodes and sometimes on top of nodes. If the mode
+ "nodesfirst" is chosen, all nodes are drawn first, followed by the
+ edges. This guarantees an edge-node overlap will not be mistaken for
+ an edge ending at a node. On the other hand, usually for aesthetic
+ reasons, it may be desirable that all edges appear beneath nodes, even
+ if the resulting drawing is ambiguous. This can be achieved by choosing
+ "edgesfirst".
+
+<DT><A NAME=k:packMode><STRONG>packMode</STRONG></A>
+<DD>"node","clust","graph"
+ These specify the granularity of packing connected components when
+ the <A HREF=#d:pack>pack</A> attribute is true. A value of "node" causes
+ packing at the node and edge label, with no overlapping of these objects.
+ This produces a layout with the least area, but it also allows interleaving,
+ where a node of one component may lie between two nodes in another
+ component. A value of "graph" does a packing using the bounding box of the
+ component. Thus, there will be a rectangular region around a component
+ free of elements of any other component.
+ A value of "clust" guarantees that top-level clusters are kept intact.
+ What effect a value has also depends on the layout algorithm. For
+ example, neato does not support clusters, so a value of "clust" will
+ have the same effect as the default "node" value.
+
+<DT><A NAME=k:pagedir><STRONG>pagedir</STRONG></A>
+<DD>"BL", "BR", "TL", "TR", "RB", "RT", "LB", "LT".
+ These specify the 8 row or column major orders for traversing a
+ rectangular array, the first character corresponding to the major
+ order and the second to the minor order. Thus, for "BL", the
+ major order is from bottom to top, and the minor order is from left
+ to right. This means the bottom row is traversed first, from left
+ to right, then the next row up, from left to right, and so on,
+ until the topmost row is traversed.
+
+<DT><A NAME=k:point><STRONG>point</STRONG></A>
+<DD>"%f,%f"('!') representing the point (x,y). The
+ optional '!' indicates the
+ node position should not change (input-only).
+ <P>
+ If <A HREF=#d:dim>dim</A> is 3 or more, <B>point</B> may also have
+ the format "%f,%f,%f"('!') to represent the point (x,y,z).
+
+<DT><A NAME=k:pointf><STRONG>pointf</STRONG></A>
+<DD>"%lf,%lf" representing the point (x,y).
+
+<DT><A NAME=k:pointfList><STRONG>pointfList</STRONG></A>
+<DD>list of pointf, separated by spaces.
+
+<DT><A NAME=k:portPos><STRONG>portPos</STRONG></A>
+<DD>modifier indicating where on a node an edge should be aimed.
+ It has the form <TT><I>portname</I>[:<I>compass_point</I>]</TT>
+ or <TT><I>compass_point</I></TT>.
+ If the first form is used, the corresponding node must either have
+ <A HREF=shapes.html#record>record</A> shape with one of its fields
+ having the given <I>portname</I>,
+ or have an <A HREF=shapes.html#html>HTML-like label</A>, one of
+ whose components has a <TT>PORT</TT> attribute set to <I>portname</I>.
+ <P>
+ If a compass point is used, it must have the form
+ <TT>"n","ne","e","se","s","sw","w","nw","c","_"</TT>. This modifies the edge
+ placement to aim for the corresponding compass point on the port or,
+ in the second form where no <I>portname</I> is supplied, on the node
+ itself. The compass point "c" specifies the center of the node or port.
+ The compass point "_" specifies that an appropriate side of the port
+ adjacent to the exterior of the node should be used, if such exists.
+ Otherwise, the center is used.
+ If no compass point is used with a portname, the default value is "_".
+ <P>
+ <P>
+ This attribute can be attached to an edge using the
+ <A HREF=#k:headport>headport</A> and
+ <A HREF=#k:tailport>tailport</A> attributes, or as part of the
+ edge description as in
+ <CENTER>
+ <TT>node1:port1 -> node2:port5:nw;</TT>
+ </CENTER>
+ <P>
+ Note that it is legal to have a portname the same as one of
+ the compass points. In this case, this reference will be resolved to
+ the port. Thus, if node <TT>A</TT> has a port <TT>w</TT>, then
+ <TT>headport=w</TT> will refer to the port and not the compass point.
+ At present, in this case, there is no way to specify that the compass
+ point should be used.
+
+<DT><A NAME=k:quadType><STRONG>quadType</STRONG></A>
+<DD>"normal", "fast", "none".
+ <P>
+ Using "fast" gives about a 2-4 times overall speedup compared with "normal",
+ though layout quality can suffer a little.
+
+<DT><A NAME=k:rankdir><STRONG>rankdir</STRONG></A>
+<DD>"TB", "LR", "BT", "RL", corresponding to directed graphs drawn
+ from top to bottom, from left to right, from bottom to top, and from
+ right to left, respectively.
+
+<DT><A NAME=k:rankType><STRONG>rankType</STRONG></A>
+<DD>"same", "min", "source", "max", "sink"
+
+<DT><A NAME=k:rect><STRONG>rect</STRONG></A>
+<DD>"%d,%d,%d,%d" The rect llx,lly,urx,ury gives the coordinates, in
+ points, of the lower-left corner (llx,lly) and the upper-right corner
+ (urx,ury).
+
+<DT><A NAME=k:shape><STRONG>shape</STRONG></A>
+<DD>A string specifying the <A HREF=shapes.html>shape</A> of a node.
+ There are three
+ main types of shapes :
+ <A HREF=shapes.html#polygon>polygon-based</A>,
+ <A HREF=shapes.html#record>record-based</A> and
+ <A HREF=shapes.html#epsf>user-defined</A>.
+
+<DT><A NAME=k:smoothType><STRONG>smoothType</STRONG></A>
+<DD>Values are "none", "avg_dist", "graph_dist", "power_dist", "rng",
+ "spring" and "triangle".
+
+<DT><A NAME=k:splineType><STRONG>splineType</STRONG></A>
+<DD>spline ( ';' spline )*<BR>
+ <TABLE>
+ <TR><TD ALIGN=right>where spline<TD>=<TD>(endp)? (startp)? point (triple)+</TR>
+ <TR><TD ALIGN=right>and triple<TD>=<TD>point point point</TR>
+ <TR><TD ALIGN=right>and endp<TD>=<TD>"e,%d,%d"</TR>
+ <TR><TD ALIGN=right>and startp<TD>=<TD>"s,%d,%d"</TR>
+ </TABLE>
+ If a spline has points p<SUB>1</SUB> p<SUB>2</SUB> p<SUB>3</SUB> ... p<SUB>n</SUB>, (n = 1 (mod 3)), the points
+ correspond to the control points of a B-spline from p<SUB>1</SUB> to p<SUB>n</SUB>. If startp
+ is given, it touches one node of the edge, and the arrowhead
+ goes from p<SUB>1</SUB> to startp. If startp is not given, p<SUB>1</SUB> touches a node.
+ Similarly for p<SUB>n</SUB> and endp.
+
+<DT><A NAME=k:startType><STRONG>startType</STRONG></A>
+<DD>has the syntax <TT>[<I>style</I>][<I>seed</I>]</TT>.
+ <P>
+ If <I>style</I> is present, it must be one of the strings <TT>"regular"</TT>,
+ <TT>"self"</TT>, or <TT>"random"</TT>. In the first case, the nodes are
+ placed regularly about a circle. In the second case,
+ an abbreviated version of neato is run to obtain the initial layout.
+ In the last case, the nodes are placed randomly in a unit square.
+ <P>
+ If <I>seed</I> is present, it specifies a seed for the random number
+ generator. If <I>seed</I> is a positive number, this is used as the
+ seed. If it is anything else,
+ the current time, and possibly the process id, is used to pick a seed,
+ thereby making the choice more random. In this case, the seed value
+ is stored in the graph.
+ <P>
+ If the value is just <TT>"random"</TT>, a time-based seed is chosen.
+ <P>
+ Note that input positions, specified by a node's
+ <A HREF=#d:pos>pos</A>
+ attribute, are only used when the style is <TT>"random"</TT>.
+
+<DT><A NAME=k:style><STRONG>style</STRONG></A>
+<DD>styleItem ( ',' styleItem )*<BR>
+ <TABLE>
+ <TR><TD ALIGN=right>where styleItem<TD>=<TD>name or name'('args')'</TR>
+ <TR><TD ALIGN=right>and args<TD>=<TD>name ( ',' name )*</TR>
+ <TR><TD ALIGN=right>and name<TD>=<TD>[^)(, ][^)(,]*</TR>
+ </TABLE>
+ Note that whitespace characters are ignored, except for names which
+ can contain them. A
+ name cannot contain any comma, or left or right parenthesis, and it cannot
+ begin with a whitespace character.
+ <P>
+ At present, the recognized style names are
+ "dashed", "dotted", "solid", "invis" and "bold" for nodes and edges,
+ and "filled", "diagonals" and "rounded" for nodes only.
+ The styles "filled" and "rounded" are recognized for clusters.
+ Additional styles are available in
+ device-dependent form. Style lists are passed to device drivers, which
+ can use this to generate appropriate output.
+ <P>
+ The <TT>setlinewidth</TT> style value can be
+ used for more control over the width of node borders and edges than is
+ allowed by <TT>bold</TT>. This style value takes an argument, specifying the
+ width of the line in <A HREF=#points>points</A>. For example, <TT>style="bold"</TT> is
+ equivalent to <TT>style="setlinewidth(2)"</TT>.
+ <B>The use of <TT>setlinewidth</TT> is deprecated; one should use the
+ <A HREF=#d:penwidth><TT>penwidth</TT></A> attribute instead.</B>
+
+<DT><A NAME=k:viewPort><STRONG>viewPort</STRONG></A>
+<DD>"%lf,%lf,%lf,%lf,%lf" or "%lf,%lf,%lf,'%s'"
+ <P>
+ The viewPort <TT>W,H,Z,x,y</TT> or <TT>W,H,Z,N</TT>
+ specifies a viewport for the final image. The pair (W,H) gives the
+ dimensions (width and height) of the final image, in
+ <A HREF=#points>points</A>.
+ The optional Z is the zoom factor, i.e., the image in the original layout will be
+ W/Z by H/Z points in size. By default, Z is 1.
+ The optional last part is either a pair (x,y) giving a position in the original layout of the
+ graph, in
+ <A HREF=#points>points</A>, of the center of the viewport, or the name N
+ of a node whose center should used as the focus.
+ By default, the focus is the center of the graph bounding box, i.e.,
+ (bbx/2,bby/2), where "bbx,bby" is the
+ value of the bounding box attribute <A HREF=#a:bb>bb</A>.
+ <P>
+ Sample values: <TT>50,50,.5,'2.8 BSD'</T> or <TT>100,100,2,450,300</TT>.
+ The first will take the 100x100 point square centered on the node <TT>2.8 BSD</TT>
+ and scale it down by 0.5, yielding a 50x50 point final image.
+
+</DL>
+</BODY>
+</HTML>
<A HREF=#d:plain-ext>plain-ext</A>
formats need to be interpreted in this manner.
<P>
+<TABLE ALIGN=CENTER>
+<TR><TH>Command-line<BR>parameter</TH><TH>Format</TH></TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:bmp HREF=#d:bmp>bmp</A>
+</TD><TD>Windows Bitmap Format</TD> </TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:canon HREF=#d:canon>canon</A>
+<BR><A NAME=a:dot HREF=#d:dot>dot</A>
+<BR><A NAME=a:xdot HREF=#d:xdot>xdot</A>
+</TD><TD>DOT</TD> </TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:cmap HREF=#d:cmap>cmap</A>
+</TD><TD>Client-side imagemap (deprecated)</TD> </TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:dia HREF=#d:dia>dia</A>
+</TD><TD>Dia format</TD> </TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:eps HREF=#d:eps>eps</A>
+</TD><TD>Encapsulated PostScript</TD> </TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:fig HREF=#d:fig>fig</A>
+</TD><TD>FIG</TD> </TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:gd HREF=#d:gd>gd</A>
+<BR><A NAME=a:gd2 HREF=#d:gd2>gd2</A>
+</TD><TD>GD/GD2 formats</TD> </TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:gif HREF=#d:gif>gif</A>
+</TD><TD>GIF</TD> </TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:gtk HREF=#d:gtk>gtk</A>
+</TD><TD>GTK canvas</TD> </TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:hpgl HREF=#d:hpgl>hpgl</A>
+</TD><TD>HP-GL/2</TD> </TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:ico HREF=#d:ico>ico</A>
+</TD><TD>Icon Image File Format</TD> </TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:imap HREF=#d:imap>imap</A>
+<BR><A NAME=a:cmapx HREF=#d:cmapx>cmapx</A>
+</TD><TD>Server-side and client-side imagemaps</TD> </TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:imap_np HREF=#d:imap_np>imap_np</A>
+<BR><A NAME=a:cmapx_np HREF=#d:cmapx_np>cmapx_np</A>
+</TD><TD>Server-side and client-side imagemaps</TD> </TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:ismap HREF=#d:ismap>ismap</A>
+</TD><TD>Server-side imagemap (deprecated)</TD> </TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:jpg HREF=#d:jpg>jpg</A>
+<BR><A NAME=a:jpeg HREF=#d:jpeg>jpeg</A>
+<BR><A NAME=a:jpe HREF=#d:jpe>jpe</A>
+</TD><TD>JPEG</TD> </TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:mif HREF=#d:mif>mif</A>
+</TD><TD>FrameMaker MIF format</TD> </TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:mp HREF=#d:mp>mp</A>
+</TD><TD>MetaPost</TD> </TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:pcl HREF=#d:pcl>pcl</A>
+</TD><TD>PCL</TD> </TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:pdf HREF=#d:pdf>pdf</A>
+</TD><TD>Portable Document Format (PDF)</TD> </TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:pic HREF=#d:pic>pic</A>
+</TD><TD>PIC</TD> </TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:plain HREF=#d:plain>plain</A>
+<BR><A NAME=a:plain-ext HREF=#d:plain-ext>plain-ext</A>
+</TD><TD>Simple text format</TD> </TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:png HREF=#d:png>png</A>
+</TD><TD>Portable Network Graphics format</TD> </TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:ps HREF=#d:ps>ps</A>
+</TD><TD>PostScript</TD> </TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:ps2 HREF=#d:ps2>ps2</A>
+</TD><TD>PostScript for PDF</TD> </TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:svg HREF=#d:svg>svg</A>
+<BR><A NAME=a:svgz HREF=#d:svgz>svgz</A>
+</TD><TD>Scalable Vector Graphics</TD> </TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:tga HREF=#d:tga>tga</A>
+</TD><TD>Truevision Targa Format (TGA)</TD> </TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:tif HREF=#d:tif>tif</A>
+<BR><A NAME=a:tiff HREF=#d:tiff>tiff</A>
+</TD><TD>TIFF (Tag Image File Format)</TD> </TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:vml HREF=#d:vml>vml</A>
+<BR><A NAME=a:vmlz HREF=#d:vmlz>vmlz</A>
+</TD><TD>Vector Markup Language (VML)</TD> </TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:vrml HREF=#d:vrml>vrml</A>
+</TD><TD>VRML</TD> </TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:vtx HREF=#d:vtx>vtx</A>
+</TD><TD>Visual Thought format</TD> </TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:wbmp HREF=#d:wbmp>wbmp</A>
+</TD><TD>Wireless BitMap format</TD> </TR>
+ <TR><TD ALIGN=CENTER><A NAME=a:xlib HREF=#d:xlib>xlib</A>
+</TD><TD>Xlib canvas</TD> </TR>
+</TABLE>
+<HR>
+<H2>Format Descriptions</H2>
+<DL>
+<DT><A NAME=d:bmp HREF=#a:bmp><STRONG>bmp</STRONG></A>
+<DD>Outputs images in the Windows <A HREF="http://en.wikipedia.org/wiki/Bitmap">BMP</A> format.
+
+<DT><A NAME=d:canon HREF=#a:canon><STRONG>canon</STRONG></A>
+,<DT><A NAME=d:dot HREF=#a:dot><STRONG>dot</STRONG></A>
+,<DT><A NAME=d:xdot HREF=#a:xdot><STRONG>xdot</STRONG></A>
+<DD>These formats produce output in the
+<A HREF=lang.html>dot language</A>.
+Using <B>canon</B> produces a prettyprinted version of the input,
+with no layout performed.
+<P>
+The <B>dot</B> option corresponds to attributed dot output,
+and is the default output format.
+It reproduces the input, along with layout information for the graph.
+In particular, a <A HREF=attrs.html#d:bb>bb</A> attribute is
+attached to the graph, specifying the bounding box of the drawing.
+If the graph has a label, its position is specified by the
+<A HREF=attrs.html#d:lp>lp</A> attribute.
+<P>
+Each node gets <A HREF=attrs.html#d:pos>pos</A>,
+<A HREF=attrs.html#d:width>width</A> and
+<A HREF=attrs.html#d:height>height</A> attributes. If the node is a record,
+the record rectangles are given in the
+<A HREF=attrs.html#d:rects>rects</A> attribute.
+If the node is a polygon and the
+<A HREF=attrs.html#d:vertices>vertices</A> attribute is defined, this
+attribute contains the vertices of the node.
+<P>
+Every edge is
+assigned a <A HREF=attrs.html#d:pos>pos</A> attribute,
+and if the edge has a label, the label position
+is given in <A HREF=attrs.html#d:lp>lp</A>.
+<P>
+The <B>xdot</B> format extends the
+<B>dot</B> format by providing much more detailed information about
+how graph components are drawn. It relies on additional attributes
+for nodes, edges and graphs.
+<P>
+The format is preliminary; comments and
+suggestions for better representations are welcome.
+To allow for changes in the format, Graphviz attaches the attribute
+<TT>xdotversion</TT> to the graph.
+<P>
+At present, additional drawing attributes are only attached to nodes
+and edges. There are six new attributes:
+<SPACER TYPE=VERTICAL size=10>
+<TABLE border bgcolor=beige>
+<TR><TD>_draw_<TD colspan=2>Drawing operations
+<TR><TD>_ldraw_<TD colspan=2>Label drawing
+<TR><TD>_hdraw_<TD>Head arrowhead<TD>Edge only
+<TR><TD>_tdraw_<TD>Tail arrowhead<TD>Edge only
+<TR><TD>_hldraw_<TD>Head label<TD>Edge only
+<TR><TD>_tldraw_<TD>Tail label<TD>Edge only
+</TABLE>
+<P>
+The value of these attributes consists of the concatenation of some
+(multi-)set of the following 12 rendering or attribute operations.
+(The number is parentheses gives the xdot version when the operation
+was added to the format. If no version number is given, the operation
+was in the original specification.)
+<SPACER TYPE=VERTICAL size=10>
+<TABLE border bgcolor=beige>
+<TR><TD>E x<sub>0</sub> y<sub>0</sub> w h
+<TD>Filled ellipse ((x-x<sub>0</sub>)/w)<sup>2</sup> + ((y-y<sub>0</sub>)/h)<sup>2</sup> = 1
+<TR><TD>e x<sub>0</sub> y<sub>0</sub> w h
+<TD>Unfilled ellipse ((x-x<sub>0</sub>)/w)<sup>2</sup> + ((y-y<sub>0</sub>)/h)<sup>2</sup> = 1
+<TR><TD>P n x<sub>1</sub> y<sub>1</sub> ... x<sub>n</sub> y<sub>n</sub>
+<TD>Filled polygon using the given n points
+<TR><TD>p n x<sub>1</sub> y<sub>1</sub> ... x<sub>n</sub> y<sub>n</sub>
+<TD>Unfilled polygon using the given n points
+<TR><TD>L n x<sub>1</sub> y<sub>1</sub> ... x<sub>n</sub> y<sub>n</sub>
+<TD>Polyline using the given n points
+<TR><TD>B n x<sub>1</sub> y<sub>1</sub> ... x<sub>n</sub> y<sub>n</sub>
+<TD>B-spline using the given n control points
+<TR><TD>b n x<sub>1</sub> y<sub>1</sub> ... x<sub>n</sub> y<sub>n</sub>
+<TD>Filled B-spline using the given n control points (1.1)
+<TR><TD>T x y j w n -<I>c<sub>1</sub>c<sub>2</sub>...c<sub>n</sub><I>
+<TD>Text drawn using the baseline point (x,y). The text consists of the
+n characters following '-'. The text should be left-aligned (centered,
+right-aligned) on the point if j is -1 (0, 1), respectively. The value
+w gives the width of the text as computed by the library.
+<TR><TD>C n -<I>c<sub>1</sub>c<sub>2</sub>...c<sub>n</sub><I>
+<TD>Set fill color. The color value consists of the
+n characters following '-'. (1.1)
+<TR><TD>c n -<I>c<sub>1</sub>c<sub>2</sub>...c<sub>n</sub><I>
+<TD>Set pen color. The color value consists of the
+n characters following '-'. (1.1)
+<TR><TD>F s n -<I>c<sub>1</sub>c<sub>2</sub>...c<sub>n</sub><I>
+<TD>Set font. The font size is s points. The font name consists of the
+n characters following '-'. (1.1)
+<TR><TD>S n -<I>c<sub>1</sub>c<sub>2</sub>...c<sub>n</sub><I>
+<TD>Set style attribute. The style value consists of the
+n characters following '-'. The syntax of the value is the same as
+specified for a <B>styleItem</B> in <A HREF=attrs.html#k:style>style</A>. (1.1)
+<TR><TD>I x y w h n -<I>c<sub>1</sub>c<sub>2</sub>...c<sub>n</sub><I>
+<TD>Externally-specified image drawn in the box with lower left
+corner (x,y) and upper right corner (x+w,y+h). The name of the image
+consists of the n characters following '-'. This is usually a bitmap
+image. Note that the image size, even when converted from pixels to
+points, might be different from the required size (w,h). It is
+assumed the renderer will perform the necessary scaling. (1.2)
+</TABLE>
+<SPACER TYPE=VERTICAL size=10>
+In handling alignment, the application may want to recompute the
+string width using its own rendering primitives.
+<P>
+The text operation is only used in the label attributes. Normally,
+the non-text operations are only used in the non-label attributes.
+If, however, the <A HREF=attrs.html#d:decorate>decorate</A>
+attribute is set on an edge, its label
+attribute will also contain a polyline operation.
+In addition, if a label is a complex, HTML-like label, it will also
+contain non-text operations.
+<P>
+All coordinates and sizes are in points.
+Note though that if
+an edge or node is invisible, no drawing operations are attached to it.
+<P>
+Version info:
+<TABLE border >
+<TR><TH>Xdot version</TH><TH>Graphviz version</TH></TR>
+<TR><TD>1.0</TD><TD>1.9</TD></TR>
+<TR><TD>1.1</TD><TD>2.8</TD></TR>
+<TR><TD>1.2</TD><TD>2.13</TD></TR>
+</TABLE>
+
+<DT><A NAME=d:cmap HREF=#a:cmap><STRONG>cmap</STRONG></A>
+<DD>Produces map files for client-side image maps. The cmap format is
+mostly identical to cmapx, but the latter is well-formed XML amenable
+to processing by XML tools. In particular, the cmapx output is wrapped in
+<map></map>.
+<P>
+See <A HREF=#ID>Note</A>.
+
+<DT><A NAME=d:dia HREF=#a:dia><STRONG>dia</STRONG></A>
+<DD>Produces <A HREF="http://www.gnome.org/projects/dia/">Dia</A> output.
+
+<DT><A NAME=d:eps HREF=#a:eps><STRONG>eps</STRONG></A>
+<DD>Produces Encapsulated PostScript output.
+At present, this is only guaranteed to be correct for a single
+input graph since the Bounding Box information has to appear
+at the beginning of the output, and this will be based on the first graph.
+
+<DT><A NAME=d:fig HREF=#a:fig><STRONG>fig</STRONG></A>
+<DD>Outputs graphs in the FIG graphics language.
+
+<DT><A NAME=d:gd HREF=#a:gd><STRONG>gd</STRONG></A>
+,<DT><A NAME=d:gd2 HREF=#a:gd2><STRONG>gd2</STRONG></A>
+<DD>Output images in the GD and GD2 format. These are the internal
+formats used by the gd library. The latter is compressed.
+
+<DT><A NAME=d:gif HREF=#a:gif><STRONG>gif</STRONG></A>
+<DD>Outputs GIF bitmap images.
+
+<DT><A NAME=d:gtk HREF=#a:gtk><STRONG>gtk</STRONG></A>
+<DD>Creates a <A HREF="http://www.gtk.org/">GTK</A> window and displays the output there.
+
+<DT><A NAME=d:hpgl HREF=#a:hpgl><STRONG>hpgl</STRONG></A>
+<DD>Produces output in the HP-GL/2 vector graphic printer language.
+
+<DT><A NAME=d:ico HREF=#a:ico><STRONG>ico</STRONG></A>
+<DD>Outputs images in the Windows <A HREF="http://en.wikipedia.org/wiki/ICO_(icon_image_file_format)">ICO format</A>.
+
+<DT><A NAME=d:imap HREF=#a:imap><STRONG>imap</STRONG></A>
+,<DT><A NAME=d:cmapx HREF=#a:cmapx><STRONG>cmapx</STRONG></A>
+<DD>Produces map files for server-side and client-side image maps,
+These can be used in a web page with
+a graphical form of the output, e.g. in JPEG or GIF format, to attach
+links to nodes and edges. For example, to create a server-side map
+given the dot file
+<PRE>
+/* x.dot */
+digraph mainmap {
+ URL="http://www.research.att.com/base.html";
+ command [URL="http://www.research.att.com/command.html"];
+ command -> output [URL="colors.html"];
+}
+</PRE>
+one would process the graph and generate two output files:
+<PRE>
+dot -Timap -ox.map -Tgif -ox.gif x.dot
+</PRE>
+and then refer to it in a web page:
+<XMP>
+<A HREF="x.map"><IMG SRC="x.gif" ismap="ismap" /></A>
+</XMP>
+For client-side maps, one again generates two output files:
+<PRE>
+dot -Tcmapx -ox.map -Tgif -ox.gif x.dot
+</PRE>
+and uses the HTML
+<XMP>
+<IMG SRC="x.gif" USEMAP="#mainmap" />
+... [content of x.map] ...
+</XMP>
+<A HREF=attrs.html#d:URL>URLs</A> can be attached to the root
+graph, nodes and edges. If a node has a URL, clicking in the node
+will activate the link.
+If an edge has a URL, various
+points along the edge (but not necessarily the head or tail)
+will link to it. In addition, if the edge has a
+<A HREF=attrs.html#d:label>label</A>, that will link
+to the URL.
+As for the head of the edge, this is linked to the
+<A HREF=attrs.html#d:headURL>headURL</A>, if set.
+Otherwise, it is linked to the edge's URL if that is defined.
+The analogous description holds for the tail and the
+<A HREF=attrs.html#d:tailURL>tailURL</A>.
+A URL associated with the graph is used as a default link.
+<P>
+If the URL
+of a node contains the escape sequence "\N", it will be replaced by
+the node's name.
+If the headURL is defined and contains the escape sequence "\N",
+it will be replaced by
+the <A HREF=attrs.html#d:headlabel>headlabel</A>, if defined.
+The analogous result holds for the tailURL and the
+<A HREF=attrs.html#d:taillabel>taillabel</A>.
+<P>
+See <A HREF=#ID>Note</A>.
+
+<DT><A NAME=d:imap_np HREF=#a:imap_np><STRONG>imap_np</STRONG></A>
+,<DT><A NAME=d:cmapx_np HREF=#a:cmapx_np><STRONG>cmapx_np</STRONG></A>
+<DD>These are identical to the imap and cmapx formats, except they
+rely solely on rectangles as active areas.
+
+<DT><A NAME=d:ismap HREF=#a:ismap><STRONG>ismap</STRONG></A>
+<DD>Produces HTML image map files. This is a predecessor (circa 1994)
+of the IMAP format. Most servers now use the latter.
+<A HREF=attrs.html#d:URL>URLs</A> can be attached to the root graph,
+nodes and edges. Since edge
+links are attached to edge labels, an edge must
+have a <A HREF=attrs.html#d:label>label</A> for its
+URL to be used. For both nodes and edges, if the URL has the escape
+sequence "\N" embedded in its string, this will be replaced with the
+node or edge name.
+
+<DT><A NAME=d:jpg HREF=#a:jpg><STRONG>jpg</STRONG></A>
+,<DT><A NAME=d:jpeg HREF=#a:jpeg><STRONG>jpeg</STRONG></A>
+,<DT><A NAME=d:jpe HREF=#a:jpe><STRONG>jpe</STRONG></A>
+<DD>Output JPEG compressed image files.
+
+<DT><A NAME=d:mif HREF=#a:mif><STRONG>mif</STRONG></A>
+<DD>Generates Frame Maker MIF files.
+
+<DT><A NAME=d:mp HREF=#a:mp><STRONG>mp</STRONG></A>
+<DD>Produces <A HREF="http://cm.bell-labs.com/who/hobby/MetaPost.html">MetaPost</A> output.
+
+<DT><A NAME=d:pcl HREF=#a:pcl><STRONG>pcl</STRONG></A>
+<DD>Produces output in the PCL printer language.
+<A HREF=#d:hpgl>HP-GL</A> is a subset of
+PCL, so that PCL output is the same as HP-GL, wrapped with some initial
+and final commands to set the printer to and from HP-GL mode.
+
+<DT><A NAME=d:pdf HREF=#a:pdf><STRONG>pdf</STRONG></A>
+<DD>Produces <A HREF="http://www.adobe.com/devnet/pdf/">PDF</A> output.
+(This option assumes Graphviz includes the Cairo renderer.)
+Alternatively, one can use the <A HREF="#d:ps2">ps2</A> option to
+produce PDF-compatible PostScript, and then use a ps-to-pdf converter.
+<P>
+Note: At present, this option does not support anchors, etc. To get these
+included in your PDF output, use <A HREF="#d:ps2">ps2</A>.
+
+<DT><A NAME=d:pic HREF=#a:pic><STRONG>pic</STRONG></A>
+<DD>Outputs in PIC, the picture description language in the troff-family
+
+<DT><A NAME=d:plain HREF=#a:plain><STRONG>plain</STRONG></A>
+,<DT><A NAME=d:plain-ext HREF=#a:plain-ext><STRONG>plain-ext</STRONG></A>
+<DD>The plain and plain-ext formats produce output using
+a simple, line-based language.
+The latter format differs in that, on edges, it provides port names
+on head and tail nodes when applicable.
+<P>
+There are four types of statements.
+<PRE>
+ <STRONG>graph</STRONG> <I>scale</I> <I>width</I> <I>height</I>
+ <STRONG>node</STRONG> <I>name</I> <I>x</I> <I>y</I> <I>width</I> <I>height</I> <I>label</I> <I>style</I> <I>shape</I> <I>color</I> <I>fillcolor</I>
+ <STRONG>edge</STRONG> <I>tail</I> <I>head</I> <I>n</I> <I>x<sub>1</sub></I> <I>y<sub>1</sub></I> .. <I>x<sub>n</sub></I> <I>y<sub>n</sub></I> [<I>label</I> <I>xl</I> <I>yl</I>] <I>style</I> <I>color</I>
+ <STRONG>stop</STRONG>
+</PRE>
+<DL>
+<DT><STRONG>graph</STRONG>
+<DD>The <I>width</I> and <I>height</I> values give the width and height
+of the drawing. The lower left corner of the drawing is at the origin.
+The <I>scale</I> value indicates how the drawing should be scaled
+if a <A HREF=attrs.html#d:size>size</A> attribute was given and the drawing
+needs to be scaled to conform to that size. If no scaling is necessary,
+it will be set to 1.0. Note that all graph, node and edge
+coordinates and lengths are given unscaled.
+<DT><STRONG>node</STRONG>
+<DD>The <I>name</I> value is the name of the node, and <I>x</I> and <I>y</I>
+give the node's position. The <I>width</I> and <I>height</I> are the
+width and height of the node.
+The <I>label</I>,
+<I>style</I>, <I>shape</I>, <I>color</I> and <I>fillcolor</I> give the
+node's <A HREF=attrs.html#d:label>label</A>,
+<A HREF=attrs.html#d:style>style</A>, <A HREF=attrs.html#d:shape>shape</A>,
+<A HREF=attrs.html#d:color>color</A> and
+<A HREF=attrs.html#d:fillcolor>fillcolor</A>,
+respectively, using attribute default values where necessary. If the
+node does not have a style attribute, "solid" is used.
+<DT><STRONG>edge</STRONG>
+<DD>The <I>tail</I> and <I>head</I> values give the names of the head and
+tail nodes. In plain-ext format, the head or tail name will be appended
+with a colon and a portname if the edge connects to the node at a port.
+<I>n</I> is the number of control points defining the
+B-spline forming the edge. This is followed by 2*<I>n</I> numbers giving
+the x and y coordinates of the control points in order from tail to head.
+If the edge has a <A HREF=attrs.html#d:label>label</A>, this comes next
+followed by the x and y coordinates of the label's position.
+The edge description is completed by the edge's
+<A HREF=attrs.html#d:style>style</A> and <A HREF=attrs.html#d:color>color</A>.
+As with nodes, if a style is not defined, "solid" is used.
+<P>
+<B>Note:</B> The control points given in an edge statement define the
+body of the edge. In particular, if the edge has an arrowhead to the
+head or tail node,
+there will be a gap between the last or first control points and the
+boundary of the associated node. There are at least 3 possible ways
+of handling this gap:
+<UL>
+<LI> Arrange that the input graph uses <TT>dir=none</TT>,
+<TT>arrowhead=none</TT>, or <TT>arrowtail=none</TT> for all edges.
+In this case, the terminating control points will always touch the node.
+<LI> Consider the line segment joining the control point and the center
+of the node, and determine the point where the segment intersects the
+node's boundary. Then use the control point and the intersection point
+as the main axis of an arrowhead. The problem with this approach is
+that, if the edge has a port, the edge will not be pointing to the
+center of the node. In this case, rather than use the control point
+and center point, one can use the control point and its tangent.
+<LI> Arrange that the input graph uses <TT>headclip=false</TT> or
+<TT>tailclip=false</TT>. In this case, the edge will terminate at
+the node's center rather than its boundary. If arrowheads are used,
+there will still be a gap, but normally this will occur within the
+node. The application will still need to clip the spline to the node
+boundary. Also, as with the previous item, if the edge points to
+a node port, this technique will fail.
+</UL>
+</DL>
+The output consists of one <STRONG>graph</STRONG> line, a sequence of
+<STRONG>node</STRONG> lines, one per node, a sequence of
+<STRONG>edge</STRONG> lines, one per edge, and a final <STRONG>stop</STRONG>
+line. All units are in inches, represented by a floating point number.
+<P>
+Note that the plain formats provide minimal information, really giving not
+much more than node positions and sizes, and edge spline control points.
+These formats are usually most useful to applications wanting just this
+geometric information, and willing to fill in all of the graphical details.
+The only real advantages to these formats is their terseness and their
+ease of parsing. In general, the <A HREF=#d:dot>dot</A> and
+<A HREF=#d:xdot>xdot</A> are preferable in terms of the quantity of
+information provided.
+
+<DT><A NAME=d:png HREF=#a:png><STRONG>png</STRONG></A>
+<DD>Produces output in the PNG (Portable Network Graphics) format.
+
+<DT><A NAME=d:ps HREF=#a:ps><STRONG>ps</STRONG></A>
+<DD>Produces PostScript output.
+<P>
+Note: The default PostScript renderer can only handle the Latin-1
+character set. To get non-Latin-1 characters into PostScript output,
+use <TT>-Tps:cairo</TT>, assuming your version was built with the
+Cairo renderer.
+
+<DT><A NAME=d:ps2 HREF=#a:ps2><STRONG>ps2</STRONG></A>
+<DD>Produces PostScript output with PDF notations. It is assumed the output
+will be directly converted into PDF format. The notations include PDF
+bounding box information, so that the resulting PDF file can be correctly
+used with pdf tools, such as <STRONG>pdflatex</STRONG>.
+In addition, if a node has a URL
+attribute, this gets translated into PDF code such that the node,
+when viewed in a PDF-viewer, e.g.,
+<STRONG>acroread</STRONG>,
+is a link to the given URL. If a URL is attached to the graph, this serves
+as a base, such that relative URLs on nodes are derived from it.
+
+<DT><A NAME=d:svg HREF=#a:svg><STRONG>svg</STRONG></A>
+,<DT><A NAME=d:svgz HREF=#a:svgz><STRONG>svgz</STRONG></A>
+<DD>Produce <A HREF="http://www.adobe.com/svg/">SVG</A> output,
+the latter in compressed format.
+<P>
+See <A HREF=#ID>Note</A>.
+
+<DT><A NAME=d:tga HREF=#a:tga><STRONG>tga</STRONG></A>
+<DD>Produces <A HREF="http://en.wikipedia.org/wiki/Truevision_TGA">Targa</A> output.
+
+<DT><A NAME=d:tif HREF=#a:tif><STRONG>tif</STRONG></A>
+,<DT><A NAME=d:tiff HREF=#a:tiff><STRONG>tiff</STRONG></A>
+<DD>Produces <A HREF="http://www.libtiff.org/">TIFF</A> output.
+
+<DT><A NAME=d:vml HREF=#a:vml><STRONG>vml</STRONG></A>
+,<DT><A NAME=d:vmlz HREF=#a:vmlz><STRONG>vmlz</STRONG></A>
+<DD>Produces <A HREF="http://www.w3.org/TR/NOTE-VML">VML</A> output,
+the latter in compressed format.
+<P>
+See <A HREF=#ID>Note</A>.
+
+<DT><A NAME=d:vrml HREF=#a:vrml><STRONG>vrml</STRONG></A>
+<DD>Outputs graphs in the <A HREF="http://www.vrml.org/">VRML</A> format.
+To get a 3D embedding, nodes must have a <A HREF=attrs.html#d:z>z</A>
+attribute. These can either be supplied as part of the input graph, or
+be generated by neato provided <A HREF=attrs.html#d:dim>dim</A><TT>=3</TT>
+and at least one node has a <B>z</B> value.
+<P>
+Line segments are drawn as cylinders.
+In general, VRML output relies on having the PNG library to produce images
+used to texture-fill the node shapes. However, if
+<A HREF=attrs.html#d:shape>shape</A><TT>=point</TT>,
+a node is drawn as a 3D sphere.
+
+<DT><A NAME=d:vtx HREF=#a:vtx><STRONG>vtx</STRONG></A>
+<DD>Generates graph diagrams in the format for
+<A HREF="http://www.bombshellstudios.com/samples/co/vt.html">Confluents's Visual Thought</A>.
+
+<DT><A NAME=d:wbmp HREF=#a:wbmp><STRONG>wbmp</STRONG></A>
+<DD>Produces output in the Wireless BitMap (WBMP) format, optimized for
+mobile computing.
+
+<DT><A NAME=d:xlib HREF=#a:xlib><STRONG>xlib</STRONG></A>
+<DD>Creates an <A HREF="http://en.wikipedia.org/wiki/Xlib">Xlib</A> window and displays the output there.
+
+</DL>
+<HR>
+</BODY>
+</HTML>
projects / graphviz / commitdiff
