Add comment about twopi producing the chosen root node.

diff --git a/doc/info/attrs.html b/doc/info/attrs.html
index 7d5cc4a8d94c7b5f916bc0b0ae21358b3175c2b2..c252fd8ad2c1924a416a771c617602d17ad8ddea 100644 (file)
--- a/doc/info/attrs.html
+++ b/doc/info/attrs.html
@@ -381,7 +381,7 @@ This field indicates which graph component uses the attribute.
 </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>
+</TD><TD ALIGN="CENTER">&#60;none&#62;(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>
@@ -1516,6 +1516,9 @@ This field indicates which graph component uses the attribute.
   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.
+  <P>
+  If the root attribute is defined as the empty string, twopi will reset it
+  to name of the node picked as the root node.
 
 <DT><A NAME=d:rotate HREF=#a:rotate><STRONG>rotate</STRONG></A>
 <DD>  If 90, set drawing orientation to landscape.

diff --git a/doc/infosrc/attrs b/doc/infosrc/attrs
index 34fb03e2f5df7297235165c2aa49e53d56def090..66cda24f1bcebb8308a1888eb6eb62a3941885f4 100644 (file)
--- a/doc/infosrc/attrs
+++ b/doc/infosrc/attrs
@@ -965,7 +965,7 @@ force directed model. Values larger than 1 tend to reduce
 the warping effect at the expense of less clustering.
 :resolution:G:double:96.0/0.0;  bitmap,svg
 This is a synonym for the <A HREF=#d:dpi>dpi</A> attribute.
-:root:GN:string/bool:""(graphs)/false(nodes);  twopi,circo
+:root:GN:string/bool:<none>(graphs)/false(nodes);  twopi,circo
 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
@@ -974,6 +974,9 @@ 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.
+<P>
+If the root attribute is defined as the empty string, twopi will reset it
+to name of the node picked as the root node.
 :rotate:G:int:0;
 If 90, set drawing orientation to landscape.
 :samehead:E:string:"";  dot