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[emacs.git] / lisp / calc / calc-cplx.el

;;; calc-cplx.el --- Complex number functions for Calc

;; Copyright (C) 1990, 1991, 1992, 1993, 2001 Free Software Foundation, Inc.

;; Author: David Gillespie <daveg@synaptics.com>
;; Maintainers: D. Goel <deego@gnufans.org>
;;              Colin Walters <walters@debian.org>

;; 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.

;;; Commentary:

;;; Code:

;; This file is autoloaded from calc-ext.el.
(require 'calc-ext)

(require 'calc-macs)

(defun calc-Need-calc-cplx () nil)


(defun calc-argument (arg)
  (interactive "P")
  (calc-slow-wrapper
   (calc-unary-op "arg" 'calcFunc-arg arg)))

(defun calc-re (arg)
  (interactive "P")
  (calc-slow-wrapper
   (calc-unary-op "re" 'calcFunc-re arg)))

(defun calc-im (arg)
  (interactive "P")
  (calc-slow-wrapper
   (calc-unary-op "im" 'calcFunc-im arg)))


(defun calc-polar ()
  (interactive)
  (calc-slow-wrapper
   (let ((arg (calc-top-n 1)))
     (if (or (calc-is-inverse)
             (eq (car-safe arg) 'polar))
         (calc-enter-result 1 "p-r" (list 'calcFunc-rect arg))
       (calc-enter-result 1 "r-p" (list 'calcFunc-polar arg))))))




(defun calc-complex-notation ()
  (interactive)
  (calc-wrapper
   (calc-change-mode 'calc-complex-format nil t)
   (message "Displaying complex numbers in (X,Y) format")))

(defun calc-i-notation ()
  (interactive)
  (calc-wrapper
   (calc-change-mode 'calc-complex-format 'i t)
   (message "Displaying complex numbers in X+Yi format")))

(defun calc-j-notation ()
  (interactive)
  (calc-wrapper
   (calc-change-mode 'calc-complex-format 'j t)
   (message "Displaying complex numbers in X+Yj format")))


(defun calc-polar-mode (n)
  (interactive "P")
  (calc-wrapper
   (if (if n
           (> (prefix-numeric-value n) 0)
         (eq calc-complex-mode 'cplx))
       (progn
         (calc-change-mode 'calc-complex-mode 'polar)
         (message "Preferred complex form is polar"))
     (calc-change-mode 'calc-complex-mode 'cplx)
     (message "Preferred complex form is rectangular"))))


;;;; Complex numbers.

(defun math-normalize-polar (a)
  (let ((r (math-normalize (nth 1 a)))
        (th (math-normalize (nth 2 a))))
    (cond ((math-zerop r)
           '(polar 0 0))
          ((or (math-zerop th))
           r)
          ((and (not (eq calc-angle-mode 'rad))
                (or (equal th '(float 18 1))
                    (equal th 180)))
           (math-neg r))
          ((math-negp r)
           (math-neg (list 'polar (math-neg r) th)))
          (t
           (list 'polar r th)))))


;;; Coerce A to be complex (rectangular form).  [c N]
(defun math-complex (a)
  (cond ((eq (car-safe a) 'cplx) a)
        ((eq (car-safe a) 'polar)
         (if (math-zerop (nth 1 a))
             (nth 1 a)
           (let ((sc (calcFunc-sincos (nth 2 a))))
             (list 'cplx
                   (math-mul (nth 1 a) (nth 1 sc))
                   (math-mul (nth 1 a) (nth 2 sc))))))
        (t (list 'cplx a 0))))

;;; Coerce A to be complex (polar form).  [c N]
(defun math-polar (a)
  (cond ((eq (car-safe a) 'polar) a)
        ((math-zerop a) '(polar 0 0))
        (t
         (list 'polar
               (math-abs a)
               (calcFunc-arg a)))))

;;; Multiply A by the imaginary constant i.  [N N] [Public]
(defun math-imaginary (a)
  (if (and (or (Math-objvecp a) (math-infinitep a))
           (not calc-symbolic-mode))
      (math-mul a
                (if (or (eq (car-safe a) 'polar)
                        (and (not (eq (car-safe a) 'cplx))
                             (eq calc-complex-mode 'polar)))
                    (list 'polar 1 (math-quarter-circle nil))
                  '(cplx 0 1)))
    (math-mul a '(var i var-i))))




(defun math-want-polar (a b)
  (cond ((eq (car-safe a) 'polar)
         (if (eq (car-safe b) 'cplx)
             (eq calc-complex-mode 'polar)
           t))
        ((eq (car-safe a) 'cplx)
         (if (eq (car-safe b) 'polar)
             (eq calc-complex-mode 'polar)
           nil))
        ((eq (car-safe b) 'polar)
         t)
        ((eq (car-safe b) 'cplx)
         nil)
        (t (eq calc-complex-mode 'polar))))

;;; Force A to be in the (-pi,pi] or (-180,180] range.
(defun math-fix-circular (a &optional dir)   ; [R R]
  (cond ((eq (car-safe a) 'hms)
         (cond ((and (Math-lessp 180 (nth 1 a)) (not (eq dir 1)))
                (math-fix-circular (math-add a '(float -36 1)) -1))
               ((or (Math-lessp -180 (nth 1 a)) (eq dir -1))
                a)
               (t
                (math-fix-circular (math-add a '(float 36 1)) 1))))
        ((eq calc-angle-mode 'rad)
         (cond ((and (Math-lessp (math-pi) a) (not (eq dir 1)))
                (math-fix-circular (math-sub a (math-two-pi)) -1))
               ((or (Math-lessp (math-neg (math-pi)) a) (eq dir -1))
                a)
               (t
                (math-fix-circular (math-add a (math-two-pi)) 1))))
        (t
         (cond ((and (Math-lessp '(float 18 1) a) (not (eq dir 1)))
                (math-fix-circular (math-add a '(float -36 1)) -1))
               ((or (Math-lessp '(float -18 1) a) (eq dir -1))
                a)
               (t
                (math-fix-circular (math-add a '(float 36 1)) 1))))))


;;;; Complex numbers.

(defun calcFunc-polar (a)   ; [C N] [Public]
  (cond ((Math-vectorp a)
         (math-map-vec 'calcFunc-polar a))
        ((Math-realp a) a)
        ((Math-numberp a)
         (math-normalize (math-polar a)))
        (t (list 'calcFunc-polar a))))

(defun calcFunc-rect (a)   ; [N N] [Public]
  (cond ((Math-vectorp a)
         (math-map-vec 'calcFunc-rect a))
        ((Math-realp a) a)
        ((Math-numberp a)
         (math-normalize (math-complex a)))
        (t (list 'calcFunc-rect a))))

;;; Compute the complex conjugate of A.  [O O] [Public]
(defun calcFunc-conj (a)
  (let (aa bb)
    (cond ((Math-realp a)
           a)
          ((eq (car a) 'cplx)
           (list 'cplx (nth 1 a) (math-neg (nth 2 a))))
          ((eq (car a) 'polar)
           (list 'polar (nth 1 a) (math-neg (nth 2 a))))
          ((eq (car a) 'vec)
           (math-map-vec 'calcFunc-conj a))
          ((eq (car a) 'calcFunc-conj)
           (nth 1 a))
          ((math-known-realp a)
           a)
          ((and (equal a '(var i var-i))
                (math-imaginary-i))
           (math-neg a))
          ((and (memq (car a) '(+ - * /))
                (progn
                  (setq aa (calcFunc-conj (nth 1 a))
                        bb (calcFunc-conj (nth 2 a)))
                  (or (not (eq (car-safe aa) 'calcFunc-conj))
                      (not (eq (car-safe bb) 'calcFunc-conj)))))
           (if (eq (car a) '+)
               (math-add aa bb)
             (if (eq (car a) '-)
                 (math-sub aa bb)
               (if (eq (car a) '*)
                   (math-mul aa bb)
                 (math-div aa bb)))))
          ((eq (car a) 'neg)
           (math-neg (calcFunc-conj (nth 1 a))))
          ((let ((inf (math-infinitep a)))
             (and inf
                  (math-mul (calcFunc-conj (math-infinite-dir a inf)) inf))))
          (t (calc-record-why 'numberp a)
             (list 'calcFunc-conj a)))))


;;; Compute the complex argument of A.  [F N] [Public]
(defun calcFunc-arg (a)
  (cond ((Math-anglep a)
         (if (math-negp a) (math-half-circle nil) 0))
        ((eq (car-safe a) 'cplx)
         (calcFunc-arctan2 (nth 2 a) (nth 1 a)))
        ((eq (car-safe a) 'polar)
         (nth 2 a))
        ((eq (car a) 'vec)
         (math-map-vec 'calcFunc-arg a))
        ((and (equal a '(var i var-i))
              (math-imaginary-i))
         (math-quarter-circle t))
        ((and (equal a '(neg (var i var-i)))
              (math-imaginary-i))
         (math-neg (math-quarter-circle t)))
        ((let ((signs (math-possible-signs a)))
           (or (and (memq signs '(2 4 6)) 0)
               (and (eq signs 1) (math-half-circle nil)))))
        ((math-infinitep a)
         (if (or (equal a '(var uinf var-uinf))
                 (equal a '(var nan var-nan)))
             '(var nan var-nan)
           (calcFunc-arg (math-infinite-dir a))))
        (t (calc-record-why 'numvecp a)
           (list 'calcFunc-arg a))))

(defun math-imaginary-i ()
  (let ((val (calc-var-value 'var-i)))
    (or (eq (car-safe val) 'special-const)
        (equal val '(cplx 0 1))
        (and (eq (car-safe val) 'polar)
             (eq (nth 1 val) 0)
             (Math-equal (nth 1 val) (math-quarter-circle nil))))))

;;; Extract the real or complex part of a complex number.  [R N] [Public]
;;; Also extracts the real part of a modulo form.
(defun calcFunc-re (a)
  (let (aa bb)
    (cond ((Math-realp a) a)
          ((memq (car a) '(mod cplx))
           (nth 1 a))
          ((eq (car a) 'polar)
           (math-mul (nth 1 a) (calcFunc-cos (nth 2 a))))
          ((eq (car a) 'vec)
           (math-map-vec 'calcFunc-re a))
          ((math-known-realp a) a)
          ((eq (car a) 'calcFunc-conj)
           (calcFunc-re (nth 1 a)))
          ((and (equal a '(var i var-i))
                (math-imaginary-i))
           0)
          ((and (memq (car a) '(+ - *))
                (progn
                  (setq aa (calcFunc-re (nth 1 a))
                        bb (calcFunc-re (nth 2 a)))
                  (or (not (eq (car-safe aa) 'calcFunc-re))
                      (not (eq (car-safe bb) 'calcFunc-re)))))
           (if (eq (car a) '+)
               (math-add aa bb)
             (if (eq (car a) '-)
                 (math-sub aa bb)
               (math-sub (math-mul aa bb)
                         (math-mul (calcFunc-im (nth 1 a))
                                   (calcFunc-im (nth 2 a)))))))
          ((and (eq (car a) '/)
                (math-known-realp (nth 2 a)))
           (math-div (calcFunc-re (nth 1 a)) (nth 2 a)))
          ((eq (car a) 'neg)
           (math-neg (calcFunc-re (nth 1 a))))
          (t (calc-record-why 'numberp a)
             (list 'calcFunc-re a)))))

(defun calcFunc-im (a)
  (let (aa bb)
    (cond ((Math-realp a)
           (if (math-floatp a) '(float 0 0) 0))
          ((eq (car a) 'cplx)
           (nth 2 a))
          ((eq (car a) 'polar)
           (math-mul (nth 1 a) (calcFunc-sin (nth 2 a))))
          ((eq (car a) 'vec)
           (math-map-vec 'calcFunc-im a))
          ((math-known-realp a)
           0)
          ((eq (car a) 'calcFunc-conj)
           (math-neg (calcFunc-im (nth 1 a))))
          ((and (equal a '(var i var-i))
                (math-imaginary-i))
           1)
          ((and (memq (car a) '(+ - *))
                (progn
                  (setq aa (calcFunc-im (nth 1 a))
                        bb (calcFunc-im (nth 2 a)))
                  (or (not (eq (car-safe aa) 'calcFunc-im))
                      (not (eq (car-safe bb) 'calcFunc-im)))))
           (if (eq (car a) '+)
               (math-add aa bb)
             (if (eq (car a) '-)
                 (math-sub aa bb)
               (math-add (math-mul (calcFunc-re (nth 1 a)) bb)
                         (math-mul aa (calcFunc-re (nth 2 a)))))))
          ((and (eq (car a) '/)
                (math-known-realp (nth 2 a)))
           (math-div (calcFunc-im (nth 1 a)) (nth 2 a)))
          ((eq (car a) 'neg)
           (math-neg (calcFunc-im (nth 1 a))))
          (t (calc-record-why 'numberp a)
             (list 'calcFunc-im a)))))

;;; calc-cplx.el ends here