Max Alekseyev on Mon, 17 Dec 2012 17:26:53 +0100 |
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matdet vs. matdetint for large square matrices |
Dear pari-users, Description of matdetint(x) says that "when x is square, the exact determinant is obtained". I noticed that for large binary square matrices (of order several hundreds), matdetint(x) gives roughly a triple speedup. Btw, it turns out that for square matrices, matdetint(x) gives the value of determinant up to a sign not exact (the description should have reflected this fact). In general, I'm interested in a fast way of testing whether matdet(x) == 0 for an integer matrix x. In my case among matdet(x) == 0 matrank(x) < matsize(x)[1] matdetint(x) == 0 the best performance is given by the last variant. Is there anything better? Regards, Max