Modular methods for standard bases

Hi all,

My collaborator and I are trying to compute some link invariants using Singular, and long standard basis computations seem to be the main holdup. These arise from running minbase on some module with complicated coefficients in the vectors. Everything is happening over QQ with ordering dp.

I just ran across a paper by Pfister "On modular computation of standard basis" and I am completely stunned by the timings given there; so here's my question: can someone tell me whether there is a way to run modStd on a module?

A second question: I tracked down the implementation of minbase in the Singular source to idMinBase in ideals.cc (for ideals), but I failed to find how minbase for modules is implemented. Hints?

Thanks,

Daniel.

Dear Daniel,



please note that 'modStd' is implemented in "modstd.lib".
at the moment it seems to work with ideals only...



in Singular's "poly" is either polynomial or vector while "ideal" is either module or ideal.

in "idMinBase" the GB is computed by "kStd"

Regards,
Oleksandr