Issue 907 in sympy: add QRsolve to matrices

Comment #1 on issue 907 by jochen.voss: add QRsolve to matrices http://code.google.com/p/sympy/issues/detail?id=907 Here is a patch to implement the missing method (already posted to sympy-patches). Attachments: 0001-Add-a-new-Matrix.QRsolve-method.patch 3.2 KB -- You received this

Issue 1421 in sympy: QRdecomposition fails for some matrices

Status: Accepted Owner: jochen.voss Labels: Type-Defect Priority-Medium New issue 1421 by jochen.voss: QRdecomposition fails for some matrices http://code.google.com/p/sympy/issues/detail?id=1421 Hello, on the current git version of sympy I got a strange failure of the Matrix.QRdecomposition

Issue 1421 in sympy: QRdecomposition fails for some matrices

Comment #1 on issue 1421 by ondrej.certik: QRdecomposition fails for some matrices http://code.google.com/p/sympy/issues/detail?id=1421 Thanks for the bug report. One should figure out why the assertion fails: -- 968 assert Q[:,j].norm() == 1 e.g. what the norm() is, etc. --

Issue 1416 in sympy: integrate((x**3 - x)/ (x - 1), x) gives traceback

Comment #1 on issue 1416 by jochen.voss: integrate((x**3 - x)/ (x - 1), x) gives traceback http://code.google.com/p/sympy/issues/detail?id=1416 Mateusz's patch at http://groups.google.com/group/sympy-patches/browse_thread/thread/5be1e851b4568925 seems to fix the issue. With his patch applied

Issue 1417 in sympy: integrate(2**x - 2*x, x) gives traceback

Comment #1 on issue 1417 by jochen.voss: integrate(2**x - 2*x, x) gives traceback http://code.google.com/p/sympy/issues/detail?id=1417 Mateusz's patch at http://groups.google.com/group/sympy-patches/browse_thread/thread/5be1e851b4568925 seems to fix the issue. With his patch applied I get:

Issue 1419 in sympy: integrate(x/(x**2-9), x) gives wrong answers

Comment #6 on issue 1419 by jochen.voss: integrate(x/(x**2-9), x) gives wrong answers http://code.google.com/p/sympy/issues/detail?id=1419 Mateusz's patch at http://groups.google.com/group/sympy-patches/browse_thread/thread/5be1e851b4568925 seems to fix this issue. With his patch applied I

Issue 1421 in sympy: QRdecomposition fails for some matrices

Comment #2 on issue 1421 by jochen.voss: QRdecomposition fails for some matrices http://code.google.com/p/sympy/issues/detail?id=1421 Actully the three lines from the traceback, now that I look at them, show what's going on: 966 R[j,j] = tmp.norm() 967

Issue 1421 in sympy: QRdecomposition fails for some matrices

Comment #3 on issue 1421 by jochen.voss: QRdecomposition fails for some matrices http://code.google.com/p/sympy/issues/detail?id=1421 By the way, the algorithm looks like Gram-Schmidt orthonormalisation to me. Is this right? If so, the current implementation of QRsolve would probably not