[Repast-developer] Bug in NetUtilities

[<gu...@ai...>]

Hi Folks,

I think I've found a bug in NetUtilities. Namely, in
randomRewireSymmetric() (albeit I think it must be present in
randomRewire(), too).

The symptoms are that after calling the method, the list of nodes returne=
d
by getOutNodes() or getInNodes() contains a few nodes that since have bee=
n
relinked. That is, the inMap/outMap maps in DefaultNode get out of sync
with the inEdges/outEdges lists.

The reason is that the rewiring method only deals with edges from one
point of view: it rewires an edge as an inEdge or outEdge, even though an
edge is _always_ both of these (at its different edges). If it wouldn't b=
e
clear, here is an excerpt from the old code and one that I think would fi=
x
the problem:

old:

          jNode.removeInEdge (edge);

          edge.setTo (newJNode);

          newJNode.addInEdge (edge);


new:

          jNode.removeInEdge (edge);

          iNode.removeOutEdge(edge);

          edge.setTo (newJNode);

          newJNode.addInEdge (edge);

          iNode.addOutEdge(edge);


I attached my version of NetUtilities.java, which only have fixes in
randomRewireSymmetric().


Best,

-- gulya
--=20
Gulyas Laszlo   |     Laszlo Gulyas
kut.ig.         |  dir. of research
AITIA Rt.       |         AITIA Inc.