### * calc/calc-mtx.el (math-lud-pivot-check): New function.

```(math-do-matrix-lud): Use `math-lud-pivot-check' to check the size
of potential pivots.```
parent 14beddf4
 2011-02-01 Jay Belanger * calc/calc-mtx.el (math-lud-pivot-check): New function. (math-do-matrix-lud): Use `math-lud-pivot-check' to check the size of potential pivots. 2011-01-31 Alan Mackenzie * progmodes/cc-cmds.el (c-forward-over-illiterals): Continue ... ...
 ... ... @@ -232,6 +232,20 @@ (setq math-lud-cache (cons (cons m entry) math-lud-cache))) lud)))) (defun math-lud-pivot-check (a) "Determine a useful value for checking the size of potential pivots in LUD decomposition." (cond ((eq (car-safe a) 'mod) (if (and (math-integerp (nth 1 a)) (math-integerp (nth 2 a)) (eq (math-gcd (nth 1 a) (nth 2 a)) 1)) 1 0)) (t (math-abs-approx a)))) ;;; Numerical Recipes section 2.3; implicit pivoting omitted. (defun math-do-matrix-lud (m) (let* ((lu (math-copy-matrix m)) ... ... @@ -261,7 +275,7 @@ (nth j (nth k lu)))) k (1+ k))) (setcar (nthcdr j (nth i lu)) sum) (let ((dum (math-abs-approx sum))) (let ((dum (math-lud-pivot-check sum))) (if (Math-lessp big dum) (setq big dum imax i))) ... ...
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