Hi Volker, On 2018-09-02, Volker Braun <vbraun.n...@gmail.com> wrote: > FWIW I once wrote a monomial ideal implementation in Sage/Cython, probably > for some related reason though I forget exactly why I couldn't use > Singular. Its presumably similar to the code you wrote already. It doesn't > do weights but does implement the refined HS. A reasonably fast > implementation that is more flexible than Singular would surely be useful > to have. > > https://github.com/vbraun/hilbert_series/blob/master/monomial_ideal.pyx
Thank you! The similarity of my code with yours: Both rely on the following. If J is a monomial ideal and m a monomial, then HS(J)=HS(J+<m>)+t^deg(m)*HS(J:<m>) where <m> is the ideal generated by m. The non-similarities: - My code uses the Singular pexpect interface as a backend, your code avoids that slowness (but my data originally *are* in the pexpect interface, thus, I'd need a conversion to your implementation). - There are several strategies for the choice of the monomial m. You chose m as the first generator of the ideal. I try several strategies that I found in the literature. - Your code is recursive. I replace the recursion by a loop, as at some point the recursion went over the permitted limit. I will try your code on my examples. I guess it would be easy to add degree weights to your code or to implement various ways to choose m. Best regards, Simon -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
