Ticket #97 (closed defect: fixed)

Opened 1 year ago

Last modified 3 months ago

error when modeling hypergrid with number of nodes > 2 and mnimun degree of each node =1

Reported by: zhang45@indiana.edu Assigned to: nwb
Priority: low Milestone:
Component: Algorithm Version: 0.8.x
Severity: major Keywords:
Cc:

Description

1. Issue Model --> hypergrid

2. populate: number of nodes 4(or any number greater than 2)

and minimum degree of each node 1

error happens:

java.lang.IllegalArgumentException?: Vertices passed in can not be null

at edu.uci.ics.jung.graph.impl.AbstractSparseEdge?.<init>(AbstractSparseEdge?.java:91) at edu.uci.ics.jung.graph.impl.UndirectedSparseEdge?.<init>(UndirectedSparseEdge?.java:35) at edu.id.iv.modeling.p2p.hypergrid.HypergridNetwork?.buildHyperGridNetwork(HypergridNetwork?.java:100) at edu.id.iv.modeling.p2p.hypergrid.Hypergrid.execute(Hypergrid.java:35) at org.cishell.reference.gui.menumanager.menu.AlgorithmWrapper?.execute(AlgorithmWrapper?.java:109) at org.cishell.reference.app.service.scheduler.AlgorithmTask?.run(SchedulerServiceImpl?.java:680) at java.lang.Thread.run(Unknown Source)

Change History

10/04/07 18:08:40 changed by huangb@IU.EDU

  • version set to 0.8.x.
  • milestone set to 0.8.

08/13/08 14:24:30 changed by mwlinnem@IU.EDU

  • priority changed from highest to low.
  • status changed from new to closed.
  • resolution set to fixed.
  • severity changed from blocker to major.

The author of this algorithm probably meant "maximum degree of each node" instead of "minimum degree". The algorithm will consistently generate graphs with nodes below the "minimum" but never above the "maximum".

This sheds light on why it breaks with more than 2 nodes and a maximum degree of 1, because that is simply impossible for a connected graph (two nodes works, because each connects to each other, giving them a degree of one, but when you add a third node one of the original two nodes must then have a degree of 2).

I changed the label to read maximum, set the default and minimum valid value to 2, and set the number of nodes to 16, which gives a very nice graph by default.