Status: Started Owner: fredrik.johansson Labels: Type-Enhancement Priority-Medium
New issue 1289 by fredrik.johansson: Improvements to integer factorization http://code.google.com/p/sympy/issues/detail?id=1289 The patch improves factorint and related functions: * factorint returns a dict instead of a sorted list, which allows for iterating over just the factors and ignoring exponents (I think maybe the function primefactors could be removed with this change). However, this could be changed back if others don't like it. Function arguments were also changed a bit. * factorint can now efficiently factor huge numbers with many small factors, e.g. factorial(10000) or 3**10000. Removed trial(), because it is not necessary with this improvement. * factorint is now able to detect perfect powers, e.g. 19 * nextprime(10**10)**50. The helper function perfect_power tests for perfect powers. Also improved efficiency of multiplicity() * More efficient use is made of the Pollard rho and P-1 algorithms. This means in some cases, large nontrivial factors can be found that previously couldn't be found, or sometimes they may be found slightly faster. * Improved integer_nthroot, and made it fall back to mpmath's internal square root function when n == 2 Attachments: 0001-Improvements-to-integer-factorization.patch 30.3 KB -- You received this message because you are listed in the owner or CC fields of this issue, or because you starred this issue. You may adjust your issue notification preferences at: http://code.google.com/hosting/settings --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "sympy-issues" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/sympy-issues?hl=en -~----------~----~----~----~------~----~------~--~---
