diff options
Diffstat (limited to 'lisp/calc/calc-alg.el')
| -rw-r--r-- | lisp/calc/calc-alg.el | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/lisp/calc/calc-alg.el b/lisp/calc/calc-alg.el index ada18830988..a57f7ede375 100644 --- a/lisp/calc/calc-alg.el +++ b/lisp/calc/calc-alg.el @@ -91,6 +91,41 @@ (calc-top-n 1)) (and n (list (prefix-numeric-value n))))))) +;;; Write out powers (a*b*...)^n as a*b*...*a*b*... +(defun calcFunc-powerexpand (expr) + (math-normalize (math-map-tree 'math-powerexpand expr))) + +(defun math-powerexpand (expr) + (if (eq (car-safe expr) '^) + (let ((n (nth 2 expr))) + (cond ((and (integerp n) + (> n 0)) + (let ((i 1) + (a (nth 1 expr)) + (prod (nth 1 expr))) + (while (< i n) + (setq prod (math-mul prod a)) + (setq i (1+ i))) + prod)) + ((and (integerp n) + (< n 0)) + (let ((i -1) + (a (math-pow (nth 1 expr) -1)) + (prod (math-pow (nth 1 expr) -1))) + (while (> i n) + (setq prod (math-mul a prod)) + (setq i (1- i))) + prod)) + (t + expr))) + expr)) + +(defun calc-powerexpand () + (interactive) + (calc-slow-wrapper + (calc-enter-result 1 "pexp" + (calcFunc-powerexpand (calc-top-n 1))))) + (defun calc-collect (&optional var) (interactive "sCollect terms involving: ") (calc-slow-wrapper |