Function: calcFunc-lud

calcFunc-lud is an autoloaded and byte-compiled function defined in calc-mtx.el.gz.

Signature

(calcFunc-lud M)

Source Code

;; Defined in /usr/src/emacs/lisp/calc/calc-mtx.el.gz
(defun calcFunc-lud (m)
  (if (math-square-matrixp m)
      (or (math-with-extra-prec 2
	    (let ((lud (math-matrix-lud m)))
	      (and lud
		   (let* ((lmat (math-copy-matrix (car lud)))
			  (umat (math-copy-matrix (car lud)))
			  (n (1- (length (car lud))))
			  (perm (calcFunc-idn 1 n))
			  i (j 1))
		     (while (<= j n)
		       (setq i 1)
		       (while (< i j)
			 (setcar (nthcdr j (nth i lmat)) 0)
			 (setq i (1+ i)))
		       (setcar (nthcdr j (nth j lmat)) 1)
		       (while (<= (setq i (1+ i)) n)
			 (setcar (nthcdr j (nth i umat)) 0))
		       (setq j (1+ j)))
		     (while (>= (setq j (1- j)) 1)
		       (let ((pos (nth (1- j) (nth 1 lud))))
			 (or (= pos j)
			     (setq perm (math-swap-rows perm j pos)))))
		     (list 'vec perm lmat umat)))))
	  (math-reject-arg m "*Singular matrix"))
    (math-reject-arg m 'square-matrixp)))