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Diffstat (limited to 'lisp/calc/calc-frac.el')
| -rw-r--r-- | lisp/calc/calc-frac.el | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/lisp/calc/calc-frac.el b/lisp/calc/calc-frac.el new file mode 100644 index 00000000000..dc5bf6e2d2e --- /dev/null +++ b/lisp/calc/calc-frac.el @@ -0,0 +1,235 @@ +;; Calculator for GNU Emacs, part II [calc-frac.el] +;; Copyright (C) 1990, 1991, 1992, 1993 Free Software Foundation, Inc. +;; Written by Dave Gillespie, daveg@synaptics.com. + +;; This file is part of GNU Emacs. + +;; 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. + + + +;; This file is autoloaded from calc-ext.el. +(require 'calc-ext) + +(require 'calc-macs) + +(defun calc-Need-calc-frac () nil) + + +(defun calc-fdiv (arg) + (interactive "P") + (calc-slow-wrapper + (calc-binary-op ":" 'calcFunc-fdiv arg 1)) +) + + +(defun calc-fraction (arg) + (interactive "P") + (calc-slow-wrapper + (let ((func (if (calc-is-hyperbolic) 'calcFunc-frac 'calcFunc-pfrac))) + (if (eq arg 0) + (calc-enter-result 2 "frac" (list func + (calc-top-n 2) + (calc-top-n 1))) + (calc-enter-result 1 "frac" (list func + (calc-top-n 1) + (prefix-numeric-value (or arg 0))))))) +) + + +(defun calc-over-notation (fmt) + (interactive "sFraction separator (:, ::, /, //, :/): ") + (calc-wrapper + (if (string-match "\\`\\([^ 0-9][^ 0-9]?\\)[0-9]*\\'" fmt) + (let ((n nil)) + (if (/= (match-end 0) (match-end 1)) + (setq n (string-to-int (substring fmt (match-end 1))) + fmt (math-match-substring fmt 1))) + (if (eq n 0) (error "Bad denominator")) + (calc-change-mode 'calc-frac-format (list fmt n) t)) + (error "Bad fraction separator format."))) +) + +(defun calc-slash-notation (n) + (interactive "P") + (calc-wrapper + (calc-change-mode 'calc-frac-format (if n '("//" nil) '("/" nil)) t)) +) + + +(defun calc-frac-mode (n) + (interactive "P") + (calc-wrapper + (calc-change-mode 'calc-prefer-frac n nil t) + (message (if calc-prefer-frac + "Integer division will now generate fractions." + "Integer division will now generate floating-point results."))) +) + + + + + +;;;; Fractions. + +;;; Build a normalized fraction. [R I I] +;;; (This could probably be implemented more efficiently than using +;;; the plain gcd algorithm.) +(defun math-make-frac (num den) + (if (Math-integer-negp den) + (setq num (math-neg num) + den (math-neg den))) + (let ((gcd (math-gcd num den))) + (if (eq gcd 1) + (if (eq den 1) + num + (list 'frac num den)) + (if (equal gcd den) + (math-quotient num gcd) + (list 'frac (math-quotient num gcd) (math-quotient den gcd))))) +) + +(defun calc-add-fractions (a b) + (if (eq (car-safe a) 'frac) + (if (eq (car-safe b) 'frac) + (math-make-frac (math-add (math-mul (nth 1 a) (nth 2 b)) + (math-mul (nth 2 a) (nth 1 b))) + (math-mul (nth 2 a) (nth 2 b))) + (math-make-frac (math-add (nth 1 a) + (math-mul (nth 2 a) b)) + (nth 2 a))) + (math-make-frac (math-add (math-mul a (nth 2 b)) + (nth 1 b)) + (nth 2 b))) +) + +(defun calc-mul-fractions (a b) + (if (eq (car-safe a) 'frac) + (if (eq (car-safe b) 'frac) + (math-make-frac (math-mul (nth 1 a) (nth 1 b)) + (math-mul (nth 2 a) (nth 2 b))) + (math-make-frac (math-mul (nth 1 a) b) + (nth 2 a))) + (math-make-frac (math-mul a (nth 1 b)) + (nth 2 b))) +) + +(defun calc-div-fractions (a b) + (if (eq (car-safe a) 'frac) + (if (eq (car-safe b) 'frac) + (math-make-frac (math-mul (nth 1 a) (nth 2 b)) + (math-mul (nth 2 a) (nth 1 b))) + (math-make-frac (nth 1 a) + (math-mul (nth 2 a) b))) + (math-make-frac (math-mul a (nth 2 b)) + (nth 1 b))) +) + + + + +;;; Convert a real value to fractional form. [T R I; T R F] [Public] +(defun calcFunc-frac (a &optional tol) + (or tol (setq tol 0)) + (cond ((Math-ratp a) + a) + ((memq (car a) '(cplx polar vec hms date sdev intv mod)) + (cons (car a) (mapcar (function + (lambda (x) + (calcFunc-frac x tol))) + (cdr a)))) + ((Math-messy-integerp a) + (math-trunc a)) + ((Math-negp a) + (math-neg (calcFunc-frac (math-neg a) tol))) + ((not (eq (car a) 'float)) + (if (math-infinitep a) + a + (if (math-provably-integerp a) + a + (math-reject-arg a 'numberp)))) + ((integerp tol) + (if (<= tol 0) + (setq tol (+ tol calc-internal-prec))) + (calcFunc-frac a (list 'float 5 + (- (+ (math-numdigs (nth 1 a)) + (nth 2 a)) + (1+ tol))))) + ((not (eq (car tol) 'float)) + (if (Math-realp tol) + (calcFunc-frac a (math-float tol)) + (math-reject-arg tol 'realp))) + ((Math-negp tol) + (calcFunc-frac a (math-neg tol))) + ((Math-zerop tol) + (calcFunc-frac a 0)) + ((not (math-lessp-float tol '(float 1 0))) + (math-trunc a)) + ((Math-zerop a) + 0) + (t + (let ((cfrac (math-continued-fraction a tol)) + (calc-prefer-frac t)) + (math-eval-continued-fraction cfrac)))) +) + +(defun math-continued-fraction (a tol) + (let ((calc-internal-prec (+ calc-internal-prec 2))) + (let ((cfrac nil) + (aa a) + (calc-prefer-frac nil) + int) + (while (or (null cfrac) + (and (not (Math-zerop aa)) + (not (math-lessp-float + (math-abs + (math-sub a + (let ((f (math-eval-continued-fraction + cfrac))) + (math-working "Fractionalize" f) + f))) + tol)))) + (setq int (math-trunc aa) + aa (math-sub aa int) + cfrac (cons int cfrac)) + (or (Math-zerop aa) + (setq aa (math-div 1 aa)))) + cfrac)) +) + +(defun math-eval-continued-fraction (cf) + (let ((n (car cf)) + (d 1) + temp) + (while (setq cf (cdr cf)) + (setq temp (math-add (math-mul (car cf) n) d) + d n + n temp)) + (math-div n d)) +) + + + +(defun calcFunc-fdiv (a b) ; [R I I] [Public] + (if (Math-num-integerp a) + (if (Math-num-integerp b) + (if (Math-zerop b) + (math-reject-arg a "*Division by zero") + (math-make-frac (math-trunc a) (math-trunc b))) + (math-reject-arg b 'integerp)) + (math-reject-arg a 'integerp)) +) + |