--- a/src/Tools/Graphview/layout.scala Sun Jan 04 15:23:23 2015 +0100
+++ b/src/Tools/Graphview/layout.scala Sun Jan 04 16:45:41 2015 +0100
@@ -2,7 +2,13 @@
Author: Markus Kaiser, TU Muenchen
Author: Makarius
-Pendulum DAG layout algorithm.
+DAG layout algorithm, according to:
+
+ Georg Sander, "Graph Layout through the VCG Tool", in: Graph Drawing,
+ DIMACS International Workshop (GD'94), Springer LNCS 894, 1995.
+
+ http://dx.doi.org/10.1007/3-540-58950-3_371
+ ftp://ftp.cs.uni-sb.de/pub/graphics/vcg/doc/tr-A03-94.ps.gz
*/
package isabelle.graphview
@@ -261,6 +267,9 @@
}._2
}
+ /*This is an auxiliary class which is used by the layout algorithm when
+ calculating coordinates with the "pendulum method". A "region" is a
+ group of nodes which "stick together".*/
private class Region(val graph: Graph_Display.Graph, node: Key)
{
var nodes: List[Key] = List(node)