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| author | Mattias Engdegård <mattiase@acm.org> | 2020-05-13 15:17:10 +0200 |
|---|---|---|
| committer | Mattias Engdegård <mattiase@acm.org> | 2020-05-14 10:28:51 +0200 |
| commit | 1d559581b3bcd91644e44b1e3a3788614d99924f (patch) | |
| tree | 1d50f80af6168494032043f4191b486dc90f62b0 /lisp/calc/calc-mtx.el | |
| parent | a4671733b7b990e83ef6daed4d17ab240a3591b5 (diff) | |
Calc: fix LU decomposition for non-numeric matrices (bug#41223)
Computing determinant and inverse for on some matrices containing
non-numeric elements failed or gave the wrong result.
Reported by Mauro Aranda.
* lisp/calc/calc-mtx.el (math-do-matrix-lud): Don't use zero as pivot.
* test/lisp/calc/calc-tests.el (calc-matrix-determinant): New test.
Diffstat (limited to 'lisp/calc/calc-mtx.el')
| -rw-r--r-- | lisp/calc/calc-mtx.el | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/lisp/calc/calc-mtx.el b/lisp/calc/calc-mtx.el index fe241b57c60..2850b33721b 100644 --- a/lisp/calc/calc-mtx.el +++ b/lisp/calc/calc-mtx.el @@ -275,7 +275,7 @@ in LUD decomposition." k (1+ k))) (setcar (nthcdr j (nth i lu)) sum) (let ((dum (math-lud-pivot-check sum))) - (if (Math-lessp big dum) + (if (or (math-zerop big) (Math-lessp big dum)) (setq big dum imax i))) (setq i (1+ i))) |