serious inverse matrix bug? - Printable Version +- HP Forums (https://www.hpmuseum.org/forum) +-- Forum: HP Calculators (and very old HP Computers) (/forum-3.html) +--- Forum: HP Prime (/forum-5.html) +--- Thread: serious inverse matrix bug? (/thread-14103.html) |
serious inverse matrix bug? - deachp - 12-05-2019 04:49 AM Hello, I found this bug calculating the inverse of a matrix in the latest firmware, Have you guys seen it in any previous firmware before? RE: serious inverse matrix bug? - Tim Wessman - 12-05-2019 01:16 PM I forwarded on to the CAS author and it has been corrected. Only looked like it happened due to the approximate number in there. 1/2*s would have worked fine. RE: serious inverse matrix bug? - Albert Chan - 12-05-2019 01:38 PM Tried doing inverse by "hand", XCas 1.4.9-57 (win32). The bug maybe in rref() Code: XCas> m := [[1,0,1,0], [0,1/(2*s),0,1]] BTW, doing inv([[1,0], [0,1/(2.*s)]]) crash XCas. RE: serious inverse matrix bug? - parisse - 12-05-2019 07:10 PM (12-05-2019 01:38 PM)Albert Chan Wrote: The bug maybe in rref() Yes, it was a bug in rref. I fixed it by converting approx coefficients to exact (with a warning). |