Ticket #257 (closed defect: fixed)

Opened 3 months ago

Last modified 2 months ago

Random Graph algorithm produces incorrect results

Reported by: mwlinnem@IU.EDU Assigned to: nwb
Priority: normal Milestone: 1.0
Component: Algorithm Version:
Severity: critical Keywords:
Cc:

Description

The Random Graph algorithm, which tries to implement the Erdos Renyi model according to the comments in the source, produces too few edges.

Specifically, if one requests a graph of 10 nodes with a linking probability of one (that is, a 100% chance each possible link will occur), the resulting graph has 30 edges, when it should have 45 (the maximum possible).

Similarly, tests with various other probabilities leads me to believe that the algorithm is consistently under-producing edges.

Attachments

random_graph.f90 (2.3 kB) - added by mwlinnem@IU.EDU on 09/09/08 10:21:22.
corrected version of fortran code

Change History

08/20/08 13:20:47 changed by mwlinnem@IU.EDU

  • summary changed from Random Graph algorithm produced incorrect results to Random Graph algorithm produces incorrect results.

09/09/08 10:21:22 changed by mwlinnem@IU.EDU

  • attachment random_graph.f90 added.

corrected version of fortran code

09/09/08 10:23:34 changed by mwlinnem@IU.EDU

Santo submitted a new version of the fortran code which corrects the problem. We promised to integrate it into the next release, so we've got some compiling to do.

09/09/08 16:15:24 changed by mwlinnem@IU.EDU

We still need to compile for windows and mac x86.

I just tested his new code, and it works. I also compiled and committed the linux version, and updated the source in the repository. The old version has code for solaris and ppc, but if we are no longer going to support these platforms then we don't have to worry about compiling the new code for those.

09/27/08 19:31:34 changed by mwlinnem@IU.EDU

  • status changed from new to closed.
  • resolution set to fixed.