[GAP Forum] Reading strongly regular graphs into GAP

[Mathieu Dutour]

The basic strategy in that case is that you write a perl
script that reads as input the file from Spence web page
and then write as output in a format that GAP can read.

You can of course use Python or any other language that
has good text capabilities.

  Mathieu


On Fri, Mar 22, 2013 at 7:24 PM, Robert Bailey <robert.bailey at ryerson.ca>wrote:

> Dear Forum,
>
> This is perhaps not strictly a GAP question, but anyway....
>
> I've been working on some computations in GAP (using the GRAPE and other
> packages), testing certain properties of distance-regular and strongly
> regular graphs.  (I can go into more detail if necessary--but the
> SetOrbit package of Pech and Reichard has been especially useful.)
>
> There is an online catalogue of strongly regular graphs on Ted Spence's
> webpage:
> http://www.maths.gla.ac.uk/~es/srgraphs.php
>
> The graphs are given by their adjacency matrices; however, as given
> these matrices are not immediately readable by GAP.  Does anyone know of
> an easy way to convert them into the right format (i.e. adding the
> commas and brackets)?  For cases where there are a small number of
> graphs, I've been able to do search/replace in a text editor to add the
> commas, then add the brackets manually---but this isn't really feasible
> when there are 32,548 matrices of size 36x36.
>
> Thanks,
> Robert Bailey.
>
> --
> Dr. Robert Bailey
> Department of Mathematics
> Ryerson University
> 350 Victoria St.
> Toronto, Ontario M5B 2K3
> Canada
>
> Office: EPH 442B
> Telephone: +1 416-979-5000 x2874
> Web: www.math.ryerson.ca/~rbailey
>
>
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