2023-02-15 10:00:40 +0200 asked a question BUG: SageMath 9.6 for Ubuntu; inverse() with BUG: SageMath 9.6 for Ubuntu; inverse() with BUG: SageMath 9.6 for Ubuntu; inverse() A = matrix(IntegerModRing(6), [[2, 2017-11-01 14:45:42 +0200 received badge ● Famous Question (source) 2017-01-05 22:17:01 +0200 received badge ● Notable Question (source) 2016-04-21 12:08:15 +0200 commented question rational numbers with cython Sorry, I don't know how to use mpq_t attribute. Should I import some library for it? How do it? Thanks in advance. 2016-04-21 09:26:47 +0200 received badge ● Scholar (source) 2016-04-21 09:26:41 +0200 received badge ● Supporter (source) 2016-04-20 21:42:23 +0200 received badge ● Editor (source) 2016-04-20 19:41:05 +0200 commented question rational numbers with cython I re-edited with an example. Thanks. 2016-04-20 17:25:18 +0200 received badge ● Popular Question (source) 2016-04-20 17:07:20 +0200 asked a question rational numbers with cython I want to work efficiently with rational numbers under the context %cython but I dont know how. Can anyone suggest any ideas? Thank you. An example:  %cython def rational_partitions(n): sol = [i/n for i in range(n)] for a in sol[0:-1]: for b in sol[1:]: k=2 while abs(b-a)/k>1/n: sol.append(abs(b-a)/k) k += 1 return sol rational_partitions(10) ` 2015-05-04 17:05:17 +0200 received badge ● Student (source) 2015-05-04 15:59:21 +0200 asked a question LU decomposition for a matrix There is an inconsistency in the use of the LU decomposition of a matrix. If matrix A is declared in the RDF ring then P, L, U = A.LU () provides PA = LU but if A is declared in the RR ring (or QQ, ZZ,...) then A = PLU. Therefore in a case P is P.transpose () on the other.