smith normal form of a big integer matrix?

[naddi...@gmail.com]

Hi All,

I have a 625x625 integer matrix M of rank 204, and I want a 625x204 matrix A with the same image (column space). In principle I can use mingens image or mess around with smithNormalForm, but they're both much too slow. Any tips?

Magma's SmithForm is fast, but it takes me three times as long to get anything done in Magma because I don't know my way around as well as in M2, and their convention of having "image" mean row space and "kernel" mean left null space constantly trips me up.

Thanks,

Nick Addington