Update info files

diff --git a/doc/info/attrs.html b/doc/info/attrs.html
index 7d529f4dd8af5500dd4cf1de9dd1e855beea6cf7..1b27641cb7461bce4bd8ff431b08eccf2249c6f7 100644 (file)
--- a/doc/info/attrs.html
+++ b/doc/info/attrs.html
@@ -1674,15 +1674,17 @@ the given types.
 <DT><A NAME=k:viewPort><STRONG>viewPort</STRONG></A>
 <DD>"%lf,%lf,%lf,%lf,%lf" The viewPort "W,H,Z,x,y" 
   specifies a viewport for the final image. The pair (W,H) gives the
-  dimensions (width and height) of the viewport image, in pixels.
-  Z is the zoom factor, i.e., 1 point corresponds to Z pixels.
-  For example, use Z=1.34 (= 96/72) with a screen resolution of 96dpi to 
-  convert 1 inch (72 points) in the graph to 1 inch on the screen.
-  The pair (x,y) give the position in the graph, in 
+  dimensions (width and height) of the viewport image, in
+  <A HREF=#points>points</A>,
+  in the original graph drawing.
+  The optional Z is the zoom factor, i.e., the resulting image will be
+  Z*W by Z*H points in size. By default, Z is 1.
+  The optional pair (x,y) give the position in the graph, in 
   <A HREF=#points>points</A>, of the center 
   of the viewport. To focus on a particular node, (x,y) can be set to the 
   <A HREF=#a:pos>pos</A> attribute "x,y" of the node. 
-  To center on the whole graph, use (bbx/2,bby/2), where "bbx,bby" is the
+  By default, (x,y) 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>.
 
 </DL>