Number: 336
Title: Stars are not drawn well.
Submitter: Tamar Barzuza
Date: 5 Aug 03
Subsys: neato
Version: 1.9
System: Windows-XP
Severity: major
Problem:
When the graph is a star of edges with one center vertex, it is not drawn well.
Input: 
graph realization {
  n0 [shape=ellipse];
  n1 [shape=ellipse];
  n2 [shape=ellipse];
  n3 [shape=ellipse];
  n1--n0 [label="0",len=1.5];
  n2--n0 [label="1",len=1.5];
  n3--n0 [label="2",len=1.5]
}
Output file: b336.gif
Comments:
[erg] The algorithm used by neato requires it to solve an optimization problem that is very sensitive to the initial layout chosen at random. Sometimes the initial layout causes the algorithm to find a local minimum that it can't get out of. That is what you are seeing.

The simplest solution is to rerun neato, but use a different initial layout. This can be done by using -Gstart=<i>, where <i> is any integer not equal to 1. -Gstart=regular or -Gstart=x should also work.

This is somewhere between a bug and a request. There are randomization techniques to help push a solution out of a local minimum. We could add these to neato.
Owner: *
Status: Request