On Thursday, January 30, 2014 7:54:45 PM UTC+1, Jean-Pierre Flori wrote:
> On Thursday, January 30, 2014 7:35:46 PM UTC+1, Ondřej Čertík wrote: >> >> Hi, >> >> What is the state of the art library for factoring integers? >> I was under the impression, that it is the GCM-ECM library >> (http://ecm.gforge.inria.fr/). >> >> I've been trying to use ECM and I noticed the following behavior: >> >> sage: from sage.libs.libecm import ecmfactor >> sage: N = 121 >> sage: factor(N) >> 11^2 >> sage: ecmfactor(N, 1) >> (True, 121) >> sage: ecmfactor(N, 100) >> (True, 121) >> sage: ecmfactor(N, 200) >> (True, 121) >> sage: ecmfactor(N, 0) >> (True, 121) >> sage: ecmfactor(N, 0.) >> (True, 11) >> >> And I guess your problem here is also that 121 is a perfect power of a prime number, whence the discrepancy with 120. FYI its really easy and cheap to detect such perfect powers without using factorization of any kind. -- 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 http://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/groups/opt_out.
