[Maxima-commits] CVS: maxima/share/linearalgebra linalg-extra.lisp, 1.7, 1.8

[Barton W. <wil...@us...>]

Update of /cvsroot/maxima/maxima/share/linearalgebra
In directory sc8-pr-cvs16.sourceforge.net:/tmp/cvs-serv1649/share/linearalgebra

Modified Files:
	linalg-extra.lisp 
Log Message:
Better functions jacobian and hessian

Index: linalg-extra.lisp
===================================================================
RCS file: /cvsroot/maxima/maxima/share/linearalgebra/linalg-extra.lisp,v
retrieving revision 1.7
retrieving revision 1.8
diff -u -d -r1.7 -r1.8
--- linalg-extra.lisp	23 Jul 2007 11:11:13 -0000	1.7
+++ linalg-extra.lisp	23 Jul 2007 11:36:04 -0000	1.8
@@ -38,16 +38,24 @@
     (push '($matrix) mat)))
 
 (defun $hessian (e vars)
-  (if ($listp vars)
-      (let ((n ($length vars)))
-	($genmatrix `((lambda) ((mlist) i j) ($diff ,e (nth i ,vars) 1 (nth j ,vars) 1)) n n))
-    `(($hessian) ,e ,vars)))
-
+  (cond (($listp vars)
+	 (let ((z) (mat nil))
+	   (setq vars (margs vars))
+	   (dolist (vi vars)
+	     (setq z ($diff e vi))
+	     (push (cons '(mlist) (mapcar #'(lambda (s) ($diff z s)) vars)) mat))
+	   (cons '($matrix) (reverse mat))))
+	(t  `(($hessian) ,e ,vars))))
+	    
 (defun $jacobian (e vars)
-  (if (and ($listp vars) ($listp e))
-      (let ((m ($length e)) (n ($length vars)))
-	($genmatrix `((lambda) ((mlist) i j) ($diff (nth i ,e) (nth j ,vars))) m n))
-    `(($jacobian) ,e ,vars)))
+  (cond ((and ($listp vars) ($listp e))
+	 (setq e (margs e))
+	 (setq vars (margs vars))
+	 (let ((mat nil))
+	   (dolist (ei e)
+	     (push (cons '(mlist) (mapcar #'(lambda (s) ($diff ei s)) vars)) mat))
+	   (cons '($matrix) (reverse mat))))
+	(t `(($jacobian) ,e ,vars))))
 
 (defun $vandermonde_matrix (l)
   (let ((x) (row) (acc))