[GAP Forum] GAP to MATLAB?

[Iverson, Joseph W [MATH]]

Dear GAP forum,

Does anybody know of a way to efficiently get matrices (say with cyclotomic entries) from GAP to MATLAB? For instance, is there a package to export matrices as .mat files? 

I have been getting by with a jerry-rigged solution where I make GAP print a matrix like
A:=[[1,0],[0,1]];;
to a file "A.m" containing a single string like
"A=[1,0;0,1];".
Then I have MATLAB read the file as a script. That works fine for small matrices, but for large ones (or for 3-tensors consisting of lots of matrices) it is prohibitively slow, both for GAP to print to the file and for MATLAB to interpret the result. 

For a sense of scale, at the moment I would like to export 95040 matrices each of size 540x540 to MATLAB, preferably as a 3-tensor so that I can easily iterate through the list. (The matrices are the image of a representation of M12 having degree 540.)

Best regards,
Joey Iverson

Assistant Professor
Department of Mathematics
Iowa State University