[Emacs-diffs] Changes to emacs/lisp/calc/calc-ext.el

[Jay Belanger]

Index: emacs/lisp/calc/calc-ext.el
diff -c emacs/lisp/calc/calc-ext.el:1.45 emacs/lisp/calc/calc-ext.el:1.46
*** emacs/lisp/calc/calc-ext.el:1.45    Thu Jul 14 19:36:49 2005
--- emacs/lisp/calc/calc-ext.el Fri Oct 28 03:51:00 2005
***************
*** 659,665 ****
   ("calc-alg" calc-has-rules math-defsimplify
  calc-modify-simplify-mode calcFunc-collect calcFunc-esimplify
  calcFunc-islin calcFunc-islinnt calcFunc-lin calcFunc-linnt
! calcFunc-simplify calcFunc-subst math-beforep
  math-build-polynomial-expr math-expand-formula math-expr-contains
  math-expr-contains-count math-expr-depends math-expr-height
  math-expr-subst math-expr-weight math-integer-plus math-is-linear
--- 659,665 ----
   ("calc-alg" calc-has-rules math-defsimplify
  calc-modify-simplify-mode calcFunc-collect calcFunc-esimplify
  calcFunc-islin calcFunc-islinnt calcFunc-lin calcFunc-linnt
! calcFunc-simplify calcFunc-subst calcFunc-writeoutpower math-beforep
  math-build-polynomial-expr math-expand-formula math-expr-contains
  math-expr-contains-count math-expr-depends math-expr-height
  math-expr-subst math-expr-weight math-integer-plus math-is-linear
***************
*** 923,929 ****
   ("calc-alg" calc-alg-evaluate calc-apart calc-collect calc-expand
  calc-expand-formula calc-factor calc-normalize-rat calc-poly-div
  calc-poly-div-rem calc-poly-gcd calc-poly-rem calc-simplify
! calc-simplify-extended calc-substitute)
  
   ("calcalg2" calc-alt-summation calc-derivative
  calc-dump-integral-cache calc-integral calc-num-integral
--- 923,929 ----
   ("calc-alg" calc-alg-evaluate calc-apart calc-collect calc-expand
  calc-expand-formula calc-factor calc-normalize-rat calc-poly-div
  calc-poly-div-rem calc-poly-gcd calc-poly-rem calc-simplify
! calc-simplify-extended calc-substitute calc-writeoutpower)
  
   ("calcalg2" calc-alt-summation calc-derivative
  calc-dump-integral-cache calc-integral calc-num-integral
***************
*** 2106,2111 ****
--- 2106,2140 ----
    (let ((dims (math-mat-dimens a)))
      (and (cdr dims)
         (= (car dims) (nth 1 dims)))))
+ 
+ ;;; True if MAT is an identity matrix.
+ (defun math-identity-matrix-p (mat &optional mul)
+   (if (math-square-matrixp mat)
+       (let ((a (if mul
+                    (nth 1 (nth 1 mat))
+                  1))
+             (n (1- (length mat)))
+             (i 1))
+         (while (and (<= i n)
+                     (math-ident-row-p (nth i mat) i a))
+           (setq i (1+ i)))
+         (if (> i n)
+             a
+           nil))))
+ 
+ (defun math-ident-row-p (row n &optional a)
+   (unless a
+     (setq a 1))
+   (and
+    (not (memq nil (mapcar 
+                    (lambda (x) (eq x 0))
+                    (nthcdr (1+ n) row))))
+    (not (memq nil (mapcar 
+                    (lambda (x) (eq x 0))
+                    (butlast 
+                     (cdr row)
+                     (- (length row) n)))))
+    (eq (elt row n) a)))
  
  ;;; True if A is any scalar data object.  [P x]
  (defun math-objectp (a)    ;  [Public]