Update maintainer's address.

[bpt/emacs.git] / lisp / calc / calc-alg.el

diff --git a/lisp/calc/calc-alg.el b/lisp/calc/calc-alg.el
index ada1883..70900b9 100644 (file)
--- a/lisp/calc/calc-alg.el
+++ b/lisp/calc/calc-alg.el
@@ -1,27 +1,27 @@
 ;;; calc-alg.el --- algebraic functions for Calc
 
 ;; Copyright (C) 1990, 1991, 1992, 1993, 2001, 2002, 2003, 2004,
-;;   2005 Free Software Foundation, Inc.
+;;   2005, 2006, 2007 Free Software Foundation, Inc.
 
 ;; Author: David Gillespie <daveg@synaptics.com>
-;; Maintainer: Jay Belanger  <belanger@truman.edu>
+;; Maintainer: Jay Belanger  <jay.p.belanger@gmail.com>
 
 ;; This file is part of GNU Emacs.
 
+;; GNU Emacs is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 2, or (at your option)
+;; any later version.
+
 ;; GNU Emacs is distributed in the hope that it will be useful,
-;; but WITHOUT ANY WARRANTY.  No author or distributor
-;; accepts responsibility to anyone for the consequences of using it
-;; or for whether it serves any particular purpose or works at all,
-;; unless he says so in writing.  Refer to the GNU Emacs General Public
-;; License for full details.
-
-;; Everyone is granted permission to copy, modify and redistribute
-;; GNU Emacs, but only under the conditions described in the
-;; GNU Emacs General Public License.   A copy of this license is
-;; supposed to have been given to you along with GNU Emacs so you
-;; can know your rights and responsibilities.  It should be in a
-;; file named COPYING.  Among other things, the copyright notice
-;; and this notice must be preserved on all copies.
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs; see the file COPYING.  If not, write to the
+;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+;; Boston, MA 02110-1301, USA.
 
 ;;; Commentary:
 
@@ -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