(math-linear-subst-tried): New variable.

(math-do-integral):  Set `math-linear-subst-tried' to nil.

(math-do-integral-methods):  Use `math-linear-subst-tried' to
determine what type of substitution to try.

(math-integ-try-linear-substituion):  Set `math-linear-subst-tried' to
t.
This commit is contained in:
Jay Belanger 2004-11-07 23:33:29 +00:00
parent 3fc61fde57
commit 4710da05cb

View file

@ -738,8 +738,12 @@
(setcar (cdr cur-record) 'cancelled)))
(math-replace-integral-parts (car expr)))))))
(defvar math-linear-subst-tried t
"Non-nil means that a linear substitution has been tried.")
(defun math-do-integral (expr)
(let (t1 t2)
(let ((math-linear-subst-tried nil)
t1 t2)
(or (cond ((not (math-expr-contains expr math-integ-var))
(math-mul expr math-integ-var))
((equal expr math-integ-var)
@ -977,7 +981,7 @@
;; Integration by substitution, for various likely sub-expressions.
;; (In first pass, we look only for sub-exprs that are linear in X.)
(or (if math-enable-subst
(or (if math-linear-subst-tried
(math-integ-try-substitutions expr)
(math-integ-try-linear-substitutions expr))
@ -1189,6 +1193,7 @@
;;; Look for substitutions of the form u = a x + b.
(defun math-integ-try-linear-substitutions (sub-expr)
(setq math-linear-subst-tried t)
(and (not (Math-primp sub-expr))
(or (and (not (memq (car sub-expr) '(+ - * / neg)))
(not (and (eq (car sub-expr) '^)