## File: dgesv.lisp

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maxima 5.44.0-2
 `1234567891011121314151617181920212223242526272829303132` ``````;; dgesv.lisp -- Maxima interface to lapack::dgesv ;; copyright 2010 by Robert Dodier ;; I release this work under terms of the GNU General Public License. (in-package :maxima) ;; dgesv(a, b) returns solution x of linear equations a . x = b ;; as computed by the LU decomposition. ;; a is a n-by-n Maxima matrix, b is a n-by-m Maxima matrix, ;; where m maybe be greater than or equal to 1. ;; a and b are not modified. (defun \$dgesv (a b) (multiple-value-bind (a-nrow a-ncol) (maxima-matrix-dims a) (multiple-value-bind (b-nrow b-ncol) (maxima-matrix-dims b) (let ((a-mat (lapack-lispify-matrix a a-nrow a-ncol)) (b-mat (lapack-lispify-matrix b b-nrow b-ncol)) (ipiv (make-array a-nrow :element-type 'f2cl-lib:integer4))) (multiple-value-bind (z-n z-nrhs z-a z-lda z-ipiv z-b z-ldb\$ z-info) (lapack::dgesv a-nrow b-ncol a-mat a-nrow ipiv b-mat b-nrow 0) (declare (ignore z-n z-nrhs z-a z-lda z-ipiv z-b z-ldb\$)) (cond ((< z-info 0) (merror "dgesv: ~M-th argument has an illegal value." (- z-info))) ((> z-info 0) (merror "dgesv: U(~M, ~M) is exactly zero; cannot compute a solution." z-info z-info)) (t (lapack-maxify-matrix b-nrow b-ncol b-mat)))))))) ``````