IGMotifsVertexParticipation Problem

Question

I have a directed acyclic graph with 194 vertices and 492 edges. I was able to get the 3-motifs without a problem. However, when I ran IGMotifsVertexParticipation I got an error message.

I ran the example from the documentation and received the same error message. The example has a small graph named g (which I can't see to copy).

I evaluated, from the example,

mot = IGMotifsVertexParticipation[g, 3]

I get an error message

LibraryFunction::fpexc: Numeric data containing a floating point exception (NaN or Inf) encountered.

I'm using Mathematica version 12.3.1 and IGraph/M version 0.5.1

I need help to resolve the error.

Answer 1

This is a bug in IGraph/M. Mathematica 12.2 changed how LibraryLink handles NaN/Inf values and I failed to update IGMotifsVertexParticipation for compatibility. IGraph/M 0.6, which should be out by the end of September the latest (if all goes well...) will fix this.

The problem affects only Mathematica 12.2 and later.

Luckily, there are easy workarounds:

• Evaluate SetSystemOptions[ "LibraryLinkOptions" -> {"TestFloatingPointExceptions" -> False}] to disable checking for NaN/Inf values. This needs to be done every time after you restart the kernel.

• For a more permanent solution, patch IGraph/M 0.5.1 (you will need to do this again if you re-install it!):

  • Open the relevant file using the command NotebookOpen@FileNameJoin[{ParentDirectory@DirectoryName@FindFile["IGraphM`"], "GraphMotifs.m"}]

  • Scroll down to the definition of IGMotifsVertexParticipation and find the line containing check@ig@"motifsParticipation".

  • Add expectInfNaN@ in front of check. The complete line should look like this:

    Round@Developer`FromPackedArray@expectInfNaN@check@ig@"motifsParticipation"[size, ConstantArray[0, size]]