I've made modifications in https://github.com/sympy/sympy/pull/267
When I run the matrices.txt file alone all tests pass. When I run the full doctest suite I get the failure below for QR decomposition. When I shut caching off and run the suite, it passes. How can caching give a wrong answer? It's not just different, it's wrong as shown below. ********************************************************************** File "c:\documents and settings\chris\sympy\doc\src\modules\matrices.txt", line 374, in matrices.txt Failed example: Q Expected: [ ___ ___ ___] [\/ 6 -\/ 3 -\/ 2 ] [----- ------ ------] [ 6 3 2 ] [ ] [ ___ ___ ___ ] [\/ 6 -\/ 3 \/ 2 ] [----- ------ ----- ] [ 6 3 2 ] [ ] [ ___ ___ ] [\/ 6 \/ 3 ] [----- ----- 0 ] [ 3 3 ] Got: [ ___ ___] [\/ 6 -11*\/ 2 ] [----- 2/3 ---------] [ 6 18 ] [ ] [ ___ ___ ] [\/ 6 -5*\/ 2 ] [----- 2/3 -------- ] [ 6 18 ] [ ] [ ___ ___ ] [\/ 6 -2*\/ 2 ] [----- 1/3 -------- ] [ 3 9 ] ********************************************************************** File "c:\documents and settings\chris\sympy\doc\src\modules\matrices.txt", line 389, in matrices.txt Failed example: R Expected: [ ___ ] [ ___ 4*\/ 6 ___] [\/ 6 ------- 2*\/ 6 ] [ 3 ] [ ] [ ___ ] [ \/ 3 ] [ 0 ----- 0 ] [ 3 ] [ ] [ ___ ] [ 0 0 \/ 2 ] Got: [ ___ ] [ ___ 4*\/ 6 ___] [\/ 6 ------- 2*\/ 6 ] [ 3 ] [ ] [ 0 1 4 ] [ ] [ ___] [ 0 0 3*\/ 2 ] ********************************************************************** 1 items had failures: 2 of 97 in matrices.txt ***Test Failed*** 2 failures. doc\src\modules\matrices.txt [97] [2] This wouldn't be so bad, but Q*R doesn' even equal the original matrix, giving h[2] >>> pprint(Q) [ ___ ___] [\/ 6 -11*\/ 2 ] [----- 2/3 ---------] [ 6 18 ] [ ] [ ___ ___ ] [\/ 6 -5*\/ 2 ] [----- 2/3 -------- ] [ 6 18 ] [ ] [ ___ ___ ] [\/ 6 -2*\/ 2 ] [----- 1/3 -------- ] [ 3 9 ] h[2] >>> pprint(R) [ ___ ] [ ___ 4*\/ 6 ___] [\/ 6 ------- 2*\/ 6 ] [ 3 ] [ ] [ 0 1 4 ] [ ] [ ___] [ 0 0 3*\/ 2 ] h[2] >>> Q*R [1, 2, 1] [1, 2, 3] [2, 3, 4] Q*R should be [1, 1, 1] [1, 1, 3] [2, 3, 4] Does anyone have any idea what the problem might be? I don't even know how to go about debuging this? /c -- You received this message because you are subscribed to the Google Groups "sympy" group. To post to this group, send email to sympy@googlegroups.com. To unsubscribe from this group, send email to sympy+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sympy?hl=en.