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[bpt/emacs.git] / lisp / calc / calcalg2.el
1 ;;; calcalg2.el --- more algebraic functions for Calc
2
3 ;; Copyright (C) 1990, 1991, 1992, 1993, 2001 Free Software Foundation, Inc.
4
5 ;; Author: David Gillespie <daveg@synaptics.com>
6 ;; Maintainers: D. Goel <deego@gnufans.org>
7 ;; Colin Walters <walters@debian.org>
8
9 ;; This file is part of GNU Emacs.
10
11 ;; GNU Emacs is distributed in the hope that it will be useful,
12 ;; but WITHOUT ANY WARRANTY. No author or distributor
13 ;; accepts responsibility to anyone for the consequences of using it
14 ;; or for whether it serves any particular purpose or works at all,
15 ;; unless he says so in writing. Refer to the GNU Emacs General Public
16 ;; License for full details.
17
18 ;; Everyone is granted permission to copy, modify and redistribute
19 ;; GNU Emacs, but only under the conditions described in the
20 ;; GNU Emacs General Public License. A copy of this license is
21 ;; supposed to have been given to you along with GNU Emacs so you
22 ;; can know your rights and responsibilities. It should be in a
23 ;; file named COPYING. Among other things, the copyright notice
24 ;; and this notice must be preserved on all copies.
25
26 ;;; Commentary:
27
28 ;;; Code:
29
30 ;; This file is autoloaded from calc-ext.el.
31 (require 'calc-ext)
32
33 (require 'calc-macs)
34
35 (defun calc-Need-calc-alg-2 () nil)
36
37
38 (defun calc-derivative (var num)
39 (interactive "sDifferentiate with respect to: \np")
40 (calc-slow-wrapper
41 (when (< num 0)
42 (error "Order of derivative must be positive"))
43 (let ((func (if (calc-is-hyperbolic) 'calcFunc-tderiv 'calcFunc-deriv))
44 n expr)
45 (if (or (equal var "") (equal var "$"))
46 (setq n 2
47 expr (calc-top-n 2)
48 var (calc-top-n 1))
49 (setq var (math-read-expr var))
50 (when (eq (car-safe var) 'error)
51 (error "Bad format in expression: %s" (nth 1 var)))
52 (setq n 1
53 expr (calc-top-n 1)))
54 (while (>= (setq num (1- num)) 0)
55 (setq expr (list func expr var)))
56 (calc-enter-result n "derv" expr))))
57
58 (defun calc-integral (var)
59 (interactive "sIntegration variable: ")
60 (calc-slow-wrapper
61 (if (or (equal var "") (equal var "$"))
62 (calc-enter-result 2 "intg" (list 'calcFunc-integ
63 (calc-top-n 2)
64 (calc-top-n 1)))
65 (let ((var (math-read-expr var)))
66 (if (eq (car-safe var) 'error)
67 (error "Bad format in expression: %s" (nth 1 var)))
68 (calc-enter-result 1 "intg" (list 'calcFunc-integ
69 (calc-top-n 1)
70 var))))))
71
72 (defun calc-num-integral (&optional varname lowname highname)
73 (interactive "sIntegration variable: ")
74 (calc-tabular-command 'calcFunc-ninteg "Integration" "nint"
75 nil varname lowname highname))
76
77 (defun calc-summation (arg &optional varname lowname highname)
78 (interactive "P\nsSummation variable: ")
79 (calc-tabular-command 'calcFunc-sum "Summation" "sum"
80 arg varname lowname highname))
81
82 (defun calc-alt-summation (arg &optional varname lowname highname)
83 (interactive "P\nsSummation variable: ")
84 (calc-tabular-command 'calcFunc-asum "Summation" "asum"
85 arg varname lowname highname))
86
87 (defun calc-product (arg &optional varname lowname highname)
88 (interactive "P\nsIndex variable: ")
89 (calc-tabular-command 'calcFunc-prod "Index" "prod"
90 arg varname lowname highname))
91
92 (defun calc-tabulate (arg &optional varname lowname highname)
93 (interactive "P\nsIndex variable: ")
94 (calc-tabular-command 'calcFunc-table "Index" "tabl"
95 arg varname lowname highname))
96
97 (defun calc-tabular-command (func prompt prefix arg varname lowname highname)
98 (calc-slow-wrapper
99 (let (var (low nil) (high nil) (step nil) stepname stepnum (num 1) expr)
100 (if (consp arg)
101 (setq stepnum 1)
102 (setq stepnum 0))
103 (if (or (equal varname "") (equal varname "$") (null varname))
104 (setq high (calc-top-n (+ stepnum 1))
105 low (calc-top-n (+ stepnum 2))
106 var (calc-top-n (+ stepnum 3))
107 num (+ stepnum 4))
108 (setq var (if (stringp varname) (math-read-expr varname) varname))
109 (if (eq (car-safe var) 'error)
110 (error "Bad format in expression: %s" (nth 1 var)))
111 (or lowname
112 (setq lowname (read-string (concat prompt " variable: " varname
113 ", from: "))))
114 (if (or (equal lowname "") (equal lowname "$"))
115 (setq high (calc-top-n (+ stepnum 1))
116 low (calc-top-n (+ stepnum 2))
117 num (+ stepnum 3))
118 (setq low (if (stringp lowname) (math-read-expr lowname) lowname))
119 (if (eq (car-safe low) 'error)
120 (error "Bad format in expression: %s" (nth 1 low)))
121 (or highname
122 (setq highname (read-string (concat prompt " variable: " varname
123 ", from: " lowname
124 ", to: "))))
125 (if (or (equal highname "") (equal highname "$"))
126 (setq high (calc-top-n (+ stepnum 1))
127 num (+ stepnum 2))
128 (setq high (if (stringp highname) (math-read-expr highname)
129 highname))
130 (if (eq (car-safe high) 'error)
131 (error "Bad format in expression: %s" (nth 1 high)))
132 (if (consp arg)
133 (progn
134 (setq stepname (read-string (concat prompt " variable: "
135 varname
136 ", from: " lowname
137 ", to: " highname
138 ", step: ")))
139 (if (or (equal stepname "") (equal stepname "$"))
140 (setq step (calc-top-n 1)
141 num 2)
142 (setq step (math-read-expr stepname))
143 (if (eq (car-safe step) 'error)
144 (error "Bad format in expression: %s"
145 (nth 1 step)))))))))
146 (or step
147 (if (consp arg)
148 (setq step (calc-top-n 1))
149 (if arg
150 (setq step (prefix-numeric-value arg)))))
151 (setq expr (calc-top-n num))
152 (calc-enter-result num prefix (append (list func expr var low high)
153 (and step (list step)))))))
154
155 (defun calc-solve-for (var)
156 (interactive "sVariable to solve for: ")
157 (calc-slow-wrapper
158 (let ((func (if (calc-is-inverse)
159 (if (calc-is-hyperbolic) 'calcFunc-ffinv 'calcFunc-finv)
160 (if (calc-is-hyperbolic) 'calcFunc-fsolve 'calcFunc-solve))))
161 (if (or (equal var "") (equal var "$"))
162 (calc-enter-result 2 "solv" (list func
163 (calc-top-n 2)
164 (calc-top-n 1)))
165 (let ((var (if (and (string-match ",\\|[^ ] +[^ ]" var)
166 (not (string-match "\\[" var)))
167 (math-read-expr (concat "[" var "]"))
168 (math-read-expr var))))
169 (if (eq (car-safe var) 'error)
170 (error "Bad format in expression: %s" (nth 1 var)))
171 (calc-enter-result 1 "solv" (list func
172 (calc-top-n 1)
173 var)))))))
174
175 (defun calc-poly-roots (var)
176 (interactive "sVariable to solve for: ")
177 (calc-slow-wrapper
178 (if (or (equal var "") (equal var "$"))
179 (calc-enter-result 2 "prts" (list 'calcFunc-roots
180 (calc-top-n 2)
181 (calc-top-n 1)))
182 (let ((var (if (and (string-match ",\\|[^ ] +[^ ]" var)
183 (not (string-match "\\[" var)))
184 (math-read-expr (concat "[" var "]"))
185 (math-read-expr var))))
186 (if (eq (car-safe var) 'error)
187 (error "Bad format in expression: %s" (nth 1 var)))
188 (calc-enter-result 1 "prts" (list 'calcFunc-roots
189 (calc-top-n 1)
190 var))))))
191
192 (defun calc-taylor (var nterms)
193 (interactive "sTaylor expansion variable: \nNNumber of terms: ")
194 (calc-slow-wrapper
195 (let ((var (math-read-expr var)))
196 (if (eq (car-safe var) 'error)
197 (error "Bad format in expression: %s" (nth 1 var)))
198 (calc-enter-result 1 "tylr" (list 'calcFunc-taylor
199 (calc-top-n 1)
200 var
201 (prefix-numeric-value nterms))))))
202
203
204 (defun math-derivative (expr) ; uses global values: deriv-var, deriv-total.
205 (cond ((equal expr deriv-var)
206 1)
207 ((or (Math-scalarp expr)
208 (eq (car expr) 'sdev)
209 (and (eq (car expr) 'var)
210 (or (not deriv-total)
211 (math-const-var expr)
212 (progn
213 (math-setup-declarations)
214 (memq 'const (nth 1 (or (assq (nth 2 expr)
215 math-decls-cache)
216 math-decls-all)))))))
217 0)
218 ((eq (car expr) '+)
219 (math-add (math-derivative (nth 1 expr))
220 (math-derivative (nth 2 expr))))
221 ((eq (car expr) '-)
222 (math-sub (math-derivative (nth 1 expr))
223 (math-derivative (nth 2 expr))))
224 ((memq (car expr) '(calcFunc-eq calcFunc-neq calcFunc-lt
225 calcFunc-gt calcFunc-leq calcFunc-geq))
226 (list (car expr)
227 (math-derivative (nth 1 expr))
228 (math-derivative (nth 2 expr))))
229 ((eq (car expr) 'neg)
230 (math-neg (math-derivative (nth 1 expr))))
231 ((eq (car expr) '*)
232 (math-add (math-mul (nth 2 expr)
233 (math-derivative (nth 1 expr)))
234 (math-mul (nth 1 expr)
235 (math-derivative (nth 2 expr)))))
236 ((eq (car expr) '/)
237 (math-sub (math-div (math-derivative (nth 1 expr))
238 (nth 2 expr))
239 (math-div (math-mul (nth 1 expr)
240 (math-derivative (nth 2 expr)))
241 (math-sqr (nth 2 expr)))))
242 ((eq (car expr) '^)
243 (let ((du (math-derivative (nth 1 expr)))
244 (dv (math-derivative (nth 2 expr))))
245 (or (Math-zerop du)
246 (setq du (math-mul (nth 2 expr)
247 (math-mul (math-normalize
248 (list '^
249 (nth 1 expr)
250 (math-add (nth 2 expr) -1)))
251 du))))
252 (or (Math-zerop dv)
253 (setq dv (math-mul (math-normalize
254 (list 'calcFunc-ln (nth 1 expr)))
255 (math-mul expr dv))))
256 (math-add du dv)))
257 ((eq (car expr) '%)
258 (math-derivative (nth 1 expr))) ; a reasonable definition
259 ((eq (car expr) 'vec)
260 (math-map-vec 'math-derivative expr))
261 ((and (memq (car expr) '(calcFunc-conj calcFunc-re calcFunc-im))
262 (= (length expr) 2))
263 (list (car expr) (math-derivative (nth 1 expr))))
264 ((and (memq (car expr) '(calcFunc-subscr calcFunc-mrow calcFunc-mcol))
265 (= (length expr) 3))
266 (let ((d (math-derivative (nth 1 expr))))
267 (if (math-numberp d)
268 0 ; assume x and x_1 are independent vars
269 (list (car expr) d (nth 2 expr)))))
270 (t (or (and (symbolp (car expr))
271 (if (= (length expr) 2)
272 (let ((handler (get (car expr) 'math-derivative)))
273 (and handler
274 (let ((deriv (math-derivative (nth 1 expr))))
275 (if (Math-zerop deriv)
276 deriv
277 (math-mul (funcall handler (nth 1 expr))
278 deriv)))))
279 (let ((handler (get (car expr) 'math-derivative-n)))
280 (and handler
281 (funcall handler expr)))))
282 (and (not (eq deriv-symb 'pre-expand))
283 (let ((exp (math-expand-formula expr)))
284 (and exp
285 (or (let ((deriv-symb 'pre-expand))
286 (catch 'math-deriv (math-derivative expr)))
287 (math-derivative exp)))))
288 (if (or (Math-objvecp expr)
289 (eq (car expr) 'var)
290 (not (symbolp (car expr))))
291 (if deriv-symb
292 (throw 'math-deriv nil)
293 (list (if deriv-total 'calcFunc-tderiv 'calcFunc-deriv)
294 expr
295 deriv-var))
296 (let ((accum 0)
297 (arg expr)
298 (n 1)
299 derv)
300 (while (setq arg (cdr arg))
301 (or (Math-zerop (setq derv (math-derivative (car arg))))
302 (let ((func (intern (concat (symbol-name (car expr))
303 "'"
304 (if (> n 1)
305 (int-to-string n)
306 ""))))
307 (prop (cond ((= (length expr) 2)
308 'math-derivative-1)
309 ((= (length expr) 3)
310 'math-derivative-2)
311 ((= (length expr) 4)
312 'math-derivative-3)
313 ((= (length expr) 5)
314 'math-derivative-4)
315 ((= (length expr) 6)
316 'math-derivative-5))))
317 (setq accum
318 (math-add
319 accum
320 (math-mul
321 derv
322 (let ((handler (get func prop)))
323 (or (and prop handler
324 (apply handler (cdr expr)))
325 (if (and deriv-symb
326 (not (get func
327 'calc-user-defn)))
328 (throw 'math-deriv nil)
329 (cons func (cdr expr))))))))))
330 (setq n (1+ n)))
331 accum))))))
332
333 (defun calcFunc-deriv (expr deriv-var &optional deriv-value deriv-symb)
334 (let* ((deriv-total nil)
335 (res (catch 'math-deriv (math-derivative expr))))
336 (or (eq (car-safe res) 'calcFunc-deriv)
337 (null res)
338 (setq res (math-normalize res)))
339 (and res
340 (if deriv-value
341 (math-expr-subst res deriv-var deriv-value)
342 res))))
343
344 (defun calcFunc-tderiv (expr deriv-var &optional deriv-value deriv-symb)
345 (math-setup-declarations)
346 (let* ((deriv-total t)
347 (res (catch 'math-deriv (math-derivative expr))))
348 (or (eq (car-safe res) 'calcFunc-tderiv)
349 (null res)
350 (setq res (math-normalize res)))
351 (and res
352 (if deriv-value
353 (math-expr-subst res deriv-var deriv-value)
354 res))))
355
356 (put 'calcFunc-inv\' 'math-derivative-1
357 (function (lambda (u) (math-neg (math-div 1 (math-sqr u))))))
358
359 (put 'calcFunc-sqrt\' 'math-derivative-1
360 (function (lambda (u) (math-div 1 (math-mul 2 (list 'calcFunc-sqrt u))))))
361
362 (put 'calcFunc-deg\' 'math-derivative-1
363 (function (lambda (u) (math-div-float '(float 18 1) (math-pi)))))
364
365 (put 'calcFunc-rad\' 'math-derivative-1
366 (function (lambda (u) (math-pi-over-180))))
367
368 (put 'calcFunc-ln\' 'math-derivative-1
369 (function (lambda (u) (math-div 1 u))))
370
371 (put 'calcFunc-log10\' 'math-derivative-1
372 (function (lambda (u)
373 (math-div (math-div 1 (math-normalize '(calcFunc-ln 10)))
374 u))))
375
376 (put 'calcFunc-lnp1\' 'math-derivative-1
377 (function (lambda (u) (math-div 1 (math-add u 1)))))
378
379 (put 'calcFunc-log\' 'math-derivative-2
380 (function (lambda (x b)
381 (and (not (Math-zerop b))
382 (let ((lnv (math-normalize
383 (list 'calcFunc-ln b))))
384 (math-div 1 (math-mul lnv x)))))))
385
386 (put 'calcFunc-log\'2 'math-derivative-2
387 (function (lambda (x b)
388 (let ((lnv (list 'calcFunc-ln b)))
389 (math-neg (math-div (list 'calcFunc-log x b)
390 (math-mul lnv b)))))))
391
392 (put 'calcFunc-exp\' 'math-derivative-1
393 (function (lambda (u) (math-normalize (list 'calcFunc-exp u)))))
394
395 (put 'calcFunc-expm1\' 'math-derivative-1
396 (function (lambda (u) (math-normalize (list 'calcFunc-expm1 u)))))
397
398 (put 'calcFunc-sin\' 'math-derivative-1
399 (function (lambda (u) (math-to-radians-2 (math-normalize
400 (list 'calcFunc-cos u))))))
401
402 (put 'calcFunc-cos\' 'math-derivative-1
403 (function (lambda (u) (math-neg (math-to-radians-2
404 (math-normalize
405 (list 'calcFunc-sin u)))))))
406
407 (put 'calcFunc-tan\' 'math-derivative-1
408 (function (lambda (u) (math-to-radians-2
409 (math-div 1 (math-sqr
410 (math-normalize
411 (list 'calcFunc-cos u))))))))
412
413 (put 'calcFunc-arcsin\' 'math-derivative-1
414 (function (lambda (u)
415 (math-from-radians-2
416 (math-div 1 (math-normalize
417 (list 'calcFunc-sqrt
418 (math-sub 1 (math-sqr u)))))))))
419
420 (put 'calcFunc-arccos\' 'math-derivative-1
421 (function (lambda (u)
422 (math-from-radians-2
423 (math-div -1 (math-normalize
424 (list 'calcFunc-sqrt
425 (math-sub 1 (math-sqr u)))))))))
426
427 (put 'calcFunc-arctan\' 'math-derivative-1
428 (function (lambda (u) (math-from-radians-2
429 (math-div 1 (math-add 1 (math-sqr u)))))))
430
431 (put 'calcFunc-sinh\' 'math-derivative-1
432 (function (lambda (u) (math-normalize (list 'calcFunc-cosh u)))))
433
434 (put 'calcFunc-cosh\' 'math-derivative-1
435 (function (lambda (u) (math-normalize (list 'calcFunc-sinh u)))))
436
437 (put 'calcFunc-tanh\' 'math-derivative-1
438 (function (lambda (u) (math-div 1 (math-sqr
439 (math-normalize
440 (list 'calcFunc-cosh u)))))))
441
442 (put 'calcFunc-arcsinh\' 'math-derivative-1
443 (function (lambda (u)
444 (math-div 1 (math-normalize
445 (list 'calcFunc-sqrt
446 (math-add (math-sqr u) 1)))))))
447
448 (put 'calcFunc-arccosh\' 'math-derivative-1
449 (function (lambda (u)
450 (math-div 1 (math-normalize
451 (list 'calcFunc-sqrt
452 (math-add (math-sqr u) -1)))))))
453
454 (put 'calcFunc-arctanh\' 'math-derivative-1
455 (function (lambda (u) (math-div 1 (math-sub 1 (math-sqr u))))))
456
457 (put 'calcFunc-bern\'2 'math-derivative-2
458 (function (lambda (n x)
459 (math-mul n (list 'calcFunc-bern (math-add n -1) x)))))
460
461 (put 'calcFunc-euler\'2 'math-derivative-2
462 (function (lambda (n x)
463 (math-mul n (list 'calcFunc-euler (math-add n -1) x)))))
464
465 (put 'calcFunc-gammag\'2 'math-derivative-2
466 (function (lambda (a x) (math-deriv-gamma a x 1))))
467
468 (put 'calcFunc-gammaG\'2 'math-derivative-2
469 (function (lambda (a x) (math-deriv-gamma a x -1))))
470
471 (put 'calcFunc-gammaP\'2 'math-derivative-2
472 (function (lambda (a x) (math-deriv-gamma a x
473 (math-div
474 1 (math-normalize
475 (list 'calcFunc-gamma
476 a)))))))
477
478 (put 'calcFunc-gammaQ\'2 'math-derivative-2
479 (function (lambda (a x) (math-deriv-gamma a x
480 (math-div
481 -1 (math-normalize
482 (list 'calcFunc-gamma
483 a)))))))
484
485 (defun math-deriv-gamma (a x scale)
486 (math-mul scale
487 (math-mul (math-pow x (math-add a -1))
488 (list 'calcFunc-exp (math-neg x)))))
489
490 (put 'calcFunc-betaB\' 'math-derivative-3
491 (function (lambda (x a b) (math-deriv-beta x a b 1))))
492
493 (put 'calcFunc-betaI\' 'math-derivative-3
494 (function (lambda (x a b) (math-deriv-beta x a b
495 (math-div
496 1 (list 'calcFunc-beta
497 a b))))))
498
499 (defun math-deriv-beta (x a b scale)
500 (math-mul (math-mul (math-pow x (math-add a -1))
501 (math-pow (math-sub 1 x) (math-add b -1)))
502 scale))
503
504 (put 'calcFunc-erf\' 'math-derivative-1
505 (function (lambda (x) (math-div 2
506 (math-mul (list 'calcFunc-exp
507 (math-sqr x))
508 (if calc-symbolic-mode
509 '(calcFunc-sqrt
510 (var pi var-pi))
511 (math-sqrt-pi)))))))
512
513 (put 'calcFunc-erfc\' 'math-derivative-1
514 (function (lambda (x) (math-div -2
515 (math-mul (list 'calcFunc-exp
516 (math-sqr x))
517 (if calc-symbolic-mode
518 '(calcFunc-sqrt
519 (var pi var-pi))
520 (math-sqrt-pi)))))))
521
522 (put 'calcFunc-besJ\'2 'math-derivative-2
523 (function (lambda (v z) (math-div (math-sub (list 'calcFunc-besJ
524 (math-add v -1)
525 z)
526 (list 'calcFunc-besJ
527 (math-add v 1)
528 z))
529 2))))
530
531 (put 'calcFunc-besY\'2 'math-derivative-2
532 (function (lambda (v z) (math-div (math-sub (list 'calcFunc-besY
533 (math-add v -1)
534 z)
535 (list 'calcFunc-besY
536 (math-add v 1)
537 z))
538 2))))
539
540 (put 'calcFunc-sum 'math-derivative-n
541 (function
542 (lambda (expr)
543 (if (math-expr-contains (cons 'vec (cdr (cdr expr))) deriv-var)
544 (throw 'math-deriv nil)
545 (cons 'calcFunc-sum
546 (cons (math-derivative (nth 1 expr))
547 (cdr (cdr expr))))))))
548
549 (put 'calcFunc-prod 'math-derivative-n
550 (function
551 (lambda (expr)
552 (if (math-expr-contains (cons 'vec (cdr (cdr expr))) deriv-var)
553 (throw 'math-deriv nil)
554 (math-mul expr
555 (cons 'calcFunc-sum
556 (cons (math-div (math-derivative (nth 1 expr))
557 (nth 1 expr))
558 (cdr (cdr expr)))))))))
559
560 (put 'calcFunc-integ 'math-derivative-n
561 (function
562 (lambda (expr)
563 (if (= (length expr) 3)
564 (if (equal (nth 2 expr) deriv-var)
565 (nth 1 expr)
566 (math-normalize
567 (list 'calcFunc-integ
568 (math-derivative (nth 1 expr))
569 (nth 2 expr))))
570 (if (= (length expr) 5)
571 (let ((lower (math-expr-subst (nth 1 expr) (nth 2 expr)
572 (nth 3 expr)))
573 (upper (math-expr-subst (nth 1 expr) (nth 2 expr)
574 (nth 4 expr))))
575 (math-add (math-sub (math-mul upper
576 (math-derivative (nth 4 expr)))
577 (math-mul lower
578 (math-derivative (nth 3 expr))))
579 (if (equal (nth 2 expr) deriv-var)
580 0
581 (math-normalize
582 (list 'calcFunc-integ
583 (math-derivative (nth 1 expr)) (nth 2 expr)
584 (nth 3 expr) (nth 4 expr)))))))))))
585
586 (put 'calcFunc-if 'math-derivative-n
587 (function
588 (lambda (expr)
589 (and (= (length expr) 4)
590 (list 'calcFunc-if (nth 1 expr)
591 (math-derivative (nth 2 expr))
592 (math-derivative (nth 3 expr)))))))
593
594 (put 'calcFunc-subscr 'math-derivative-n
595 (function
596 (lambda (expr)
597 (and (= (length expr) 3)
598 (list 'calcFunc-subscr (nth 1 expr)
599 (math-derivative (nth 2 expr)))))))
600
601
602 (defvar math-integ-var '(var X ---))
603 (defvar math-integ-var-2 '(var Y ---))
604 (defvar math-integ-vars (list 'f math-integ-var math-integ-var-2))
605 (defvar math-integ-var-list (list math-integ-var))
606 (defvar math-integ-var-list-list (list math-integ-var-list))
607
608 (defmacro math-tracing-integral (&rest parts)
609 (list 'and
610 'trace-buffer
611 (list 'save-excursion
612 '(set-buffer trace-buffer)
613 '(goto-char (point-max))
614 (list 'and
615 '(bolp)
616 '(insert (make-string (- math-integral-limit
617 math-integ-level) 32)
618 (format "%2d " math-integ-depth)
619 (make-string math-integ-level 32)))
620 ;;(list 'condition-case 'err
621 (cons 'insert parts)
622 ;; '(error (insert (prin1-to-string err))))
623 '(sit-for 0))))
624
625 ;;; The following wrapper caches results and avoids infinite recursion.
626 ;;; Each cache entry is: ( A B ) Integral of A is B;
627 ;;; ( A N ) Integral of A failed at level N;
628 ;;; ( A busy ) Currently working on integral of A;
629 ;;; ( A parts ) Currently working, integ-by-parts;
630 ;;; ( A parts2 ) Currently working, integ-by-parts;
631 ;;; ( A cancelled ) Ignore this cache entry;
632 ;;; ( A [B] ) Same result as for cur-record = B.
633 (defun math-integral (expr &optional simplify same-as-above)
634 (let* ((simp cur-record)
635 (cur-record (assoc expr math-integral-cache))
636 (math-integ-depth (1+ math-integ-depth))
637 (val 'cancelled))
638 (math-tracing-integral "Integrating "
639 (math-format-value expr 1000)
640 "...\n")
641 (and cur-record
642 (progn
643 (math-tracing-integral "Found "
644 (math-format-value (nth 1 cur-record) 1000))
645 (and (consp (nth 1 cur-record))
646 (math-replace-integral-parts cur-record))
647 (math-tracing-integral " => "
648 (math-format-value (nth 1 cur-record) 1000)
649 "\n")))
650 (or (and cur-record
651 (not (eq (nth 1 cur-record) 'cancelled))
652 (or (not (integerp (nth 1 cur-record)))
653 (>= (nth 1 cur-record) math-integ-level)))
654 (and (math-integral-contains-parts expr)
655 (progn
656 (setq val nil)
657 t))
658 (unwind-protect
659 (progn
660 (let (math-integ-msg)
661 (if (eq calc-display-working-message 'lots)
662 (progn
663 (calc-set-command-flag 'clear-message)
664 (setq math-integ-msg (format
665 "Working... Integrating %s"
666 (math-format-flat-expr expr 0)))
667 (message math-integ-msg)))
668 (if cur-record
669 (setcar (cdr cur-record)
670 (if same-as-above (vector simp) 'busy))
671 (setq cur-record
672 (list expr (if same-as-above (vector simp) 'busy))
673 math-integral-cache (cons cur-record
674 math-integral-cache)))
675 (if (eq simplify 'yes)
676 (progn
677 (math-tracing-integral "Simplifying...")
678 (setq simp (math-simplify expr))
679 (setq val (if (equal simp expr)
680 (progn
681 (math-tracing-integral " no change\n")
682 (math-do-integral expr))
683 (math-tracing-integral " simplified\n")
684 (math-integral simp 'no t))))
685 (or (setq val (math-do-integral expr))
686 (eq simplify 'no)
687 (let ((simp (math-simplify expr)))
688 (or (equal simp expr)
689 (progn
690 (math-tracing-integral "Trying again after "
691 "simplification...\n")
692 (setq val (math-integral simp 'no t))))))))
693 (if (eq calc-display-working-message 'lots)
694 (message math-integ-msg)))
695 (setcar (cdr cur-record) (or val
696 (if (or math-enable-subst
697 (not math-any-substs))
698 math-integ-level
699 'cancelled)))))
700 (setq val cur-record)
701 (while (vectorp (nth 1 val))
702 (setq val (aref (nth 1 val) 0)))
703 (setq val (if (memq (nth 1 val) '(parts parts2))
704 (progn
705 (setcar (cdr val) 'parts2)
706 (list 'var 'PARTS val))
707 (and (consp (nth 1 val))
708 (nth 1 val))))
709 (math-tracing-integral "Integral of "
710 (math-format-value expr 1000)
711 " is "
712 (math-format-value val 1000)
713 "\n")
714 val))
715 (defvar math-integral-cache nil)
716 (defvar math-integral-cache-state nil)
717
718 (defun math-integral-contains-parts (expr)
719 (if (Math-primp expr)
720 (and (eq (car-safe expr) 'var)
721 (eq (nth 1 expr) 'PARTS)
722 (listp (nth 2 expr)))
723 (while (and (setq expr (cdr expr))
724 (not (math-integral-contains-parts (car expr)))))
725 expr))
726
727 (defun math-replace-integral-parts (expr)
728 (or (Math-primp expr)
729 (while (setq expr (cdr expr))
730 (and (consp (car expr))
731 (if (eq (car (car expr)) 'var)
732 (and (eq (nth 1 (car expr)) 'PARTS)
733 (consp (nth 2 (car expr)))
734 (if (listp (nth 1 (nth 2 (car expr))))
735 (progn
736 (setcar expr (nth 1 (nth 2 (car expr))))
737 (math-replace-integral-parts (cons 'foo expr)))
738 (setcar (cdr cur-record) 'cancelled)))
739 (math-replace-integral-parts (car expr)))))))
740
741 (defun math-do-integral (expr)
742 (let (t1 t2)
743 (or (cond ((not (math-expr-contains expr math-integ-var))
744 (math-mul expr math-integ-var))
745 ((equal expr math-integ-var)
746 (math-div (math-sqr expr) 2))
747 ((eq (car expr) '+)
748 (and (setq t1 (math-integral (nth 1 expr)))
749 (setq t2 (math-integral (nth 2 expr)))
750 (math-add t1 t2)))
751 ((eq (car expr) '-)
752 (and (setq t1 (math-integral (nth 1 expr)))
753 (setq t2 (math-integral (nth 2 expr)))
754 (math-sub t1 t2)))
755 ((eq (car expr) 'neg)
756 (and (setq t1 (math-integral (nth 1 expr)))
757 (math-neg t1)))
758 ((eq (car expr) '*)
759 (cond ((not (math-expr-contains (nth 1 expr) math-integ-var))
760 (and (setq t1 (math-integral (nth 2 expr)))
761 (math-mul (nth 1 expr) t1)))
762 ((not (math-expr-contains (nth 2 expr) math-integ-var))
763 (and (setq t1 (math-integral (nth 1 expr)))
764 (math-mul t1 (nth 2 expr))))
765 ((memq (car-safe (nth 1 expr)) '(+ -))
766 (math-integral (list (car (nth 1 expr))
767 (math-mul (nth 1 (nth 1 expr))
768 (nth 2 expr))
769 (math-mul (nth 2 (nth 1 expr))
770 (nth 2 expr)))
771 'yes t))
772 ((memq (car-safe (nth 2 expr)) '(+ -))
773 (math-integral (list (car (nth 2 expr))
774 (math-mul (nth 1 (nth 2 expr))
775 (nth 1 expr))
776 (math-mul (nth 2 (nth 2 expr))
777 (nth 1 expr)))
778 'yes t))))
779 ((eq (car expr) '/)
780 (cond ((and (not (math-expr-contains (nth 1 expr)
781 math-integ-var))
782 (not (math-equal-int (nth 1 expr) 1)))
783 (and (setq t1 (math-integral (math-div 1 (nth 2 expr))))
784 (math-mul (nth 1 expr) t1)))
785 ((not (math-expr-contains (nth 2 expr) math-integ-var))
786 (and (setq t1 (math-integral (nth 1 expr)))
787 (math-div t1 (nth 2 expr))))
788 ((and (eq (car-safe (nth 1 expr)) '*)
789 (not (math-expr-contains (nth 1 (nth 1 expr))
790 math-integ-var)))
791 (and (setq t1 (math-integral
792 (math-div (nth 2 (nth 1 expr))
793 (nth 2 expr))))
794 (math-mul t1 (nth 1 (nth 1 expr)))))
795 ((and (eq (car-safe (nth 1 expr)) '*)
796 (not (math-expr-contains (nth 2 (nth 1 expr))
797 math-integ-var)))
798 (and (setq t1 (math-integral
799 (math-div (nth 1 (nth 1 expr))
800 (nth 2 expr))))
801 (math-mul t1 (nth 2 (nth 1 expr)))))
802 ((and (eq (car-safe (nth 2 expr)) '*)
803 (not (math-expr-contains (nth 1 (nth 2 expr))
804 math-integ-var)))
805 (and (setq t1 (math-integral
806 (math-div (nth 1 expr)
807 (nth 2 (nth 2 expr)))))
808 (math-div t1 (nth 1 (nth 2 expr)))))
809 ((and (eq (car-safe (nth 2 expr)) '*)
810 (not (math-expr-contains (nth 2 (nth 2 expr))
811 math-integ-var)))
812 (and (setq t1 (math-integral
813 (math-div (nth 1 expr)
814 (nth 1 (nth 2 expr)))))
815 (math-div t1 (nth 2 (nth 2 expr)))))
816 ((eq (car-safe (nth 2 expr)) 'calcFunc-exp)
817 (math-integral
818 (math-mul (nth 1 expr)
819 (list 'calcFunc-exp
820 (math-neg (nth 1 (nth 2 expr)))))))))
821 ((eq (car expr) '^)
822 (cond ((not (math-expr-contains (nth 1 expr) math-integ-var))
823 (or (and (setq t1 (math-is-polynomial (nth 2 expr)
824 math-integ-var 1))
825 (math-div expr
826 (math-mul (nth 1 t1)
827 (math-normalize
828 (list 'calcFunc-ln
829 (nth 1 expr))))))
830 (math-integral
831 (list 'calcFunc-exp
832 (math-mul (nth 2 expr)
833 (math-normalize
834 (list 'calcFunc-ln
835 (nth 1 expr)))))
836 'yes t)))
837 ((not (math-expr-contains (nth 2 expr) math-integ-var))
838 (if (and (integerp (nth 2 expr)) (< (nth 2 expr) 0))
839 (math-integral
840 (list '/ 1 (math-pow (nth 1 expr) (- (nth 2 expr))))
841 nil t)
842 (or (and (setq t1 (math-is-polynomial (nth 1 expr)
843 math-integ-var
844 1))
845 (setq t2 (math-add (nth 2 expr) 1))
846 (math-div (math-pow (nth 1 expr) t2)
847 (math-mul t2 (nth 1 t1))))
848 (and (Math-negp (nth 2 expr))
849 (math-integral
850 (math-div 1
851 (math-pow (nth 1 expr)
852 (math-neg
853 (nth 2 expr))))
854 nil t))
855 nil))))))
856
857 ;; Integral of a polynomial.
858 (and (setq t1 (math-is-polynomial expr math-integ-var 20))
859 (let ((accum 0)
860 (n 1))
861 (while t1
862 (if (setq accum (math-add accum
863 (math-div (math-mul (car t1)
864 (math-pow
865 math-integ-var
866 n))
867 n))
868 t1 (cdr t1))
869 (setq n (1+ n))))
870 accum))
871
872 ;; Try looking it up!
873 (cond ((= (length expr) 2)
874 (and (symbolp (car expr))
875 (setq t1 (get (car expr) 'math-integral))
876 (progn
877 (while (and t1
878 (not (setq t2 (funcall (car t1)
879 (nth 1 expr)))))
880 (setq t1 (cdr t1)))
881 (and t2 (math-normalize t2)))))
882 ((= (length expr) 3)
883 (and (symbolp (car expr))
884 (setq t1 (get (car expr) 'math-integral-2))
885 (progn
886 (while (and t1
887 (not (setq t2 (funcall (car t1)
888 (nth 1 expr)
889 (nth 2 expr)))))
890 (setq t1 (cdr t1)))
891 (and t2 (math-normalize t2))))))
892
893 ;; Integral of a rational function.
894 (and (math-ratpoly-p expr math-integ-var)
895 (setq t1 (calcFunc-apart expr math-integ-var))
896 (not (equal t1 expr))
897 (math-integral t1))
898
899 ;; Try user-defined integration rules.
900 (and has-rules
901 (let ((math-old-integ (symbol-function 'calcFunc-integ))
902 (input (list 'calcFunc-integtry expr math-integ-var))
903 res part)
904 (unwind-protect
905 (progn
906 (fset 'calcFunc-integ 'math-sub-integration)
907 (setq res (math-rewrite input
908 '(var IntegRules var-IntegRules)
909 1))
910 (fset 'calcFunc-integ math-old-integ)
911 (and (not (equal res input))
912 (if (setq part (math-expr-calls
913 res '(calcFunc-integsubst)))
914 (and (memq (length part) '(3 4 5))
915 (let ((parts (mapcar
916 (function
917 (lambda (x)
918 (math-expr-subst
919 x (nth 2 part)
920 math-integ-var)))
921 (cdr part))))
922 (math-integrate-by-substitution
923 expr (car parts) t
924 (or (nth 2 parts)
925 (list 'calcFunc-integfailed
926 math-integ-var))
927 (nth 3 parts))))
928 (if (not (math-expr-calls res
929 '(calcFunc-integtry
930 calcFunc-integfailed)))
931 res))))
932 (fset 'calcFunc-integ math-old-integ))))
933
934 ;; See if the function is a symbolic derivative.
935 (and (string-match "'" (symbol-name (car expr)))
936 (let ((name (symbol-name (car expr)))
937 (p expr) (n 0) (which nil) (bad nil))
938 (while (setq n (1+ n) p (cdr p))
939 (if (equal (car p) math-integ-var)
940 (if which (setq bad t) (setq which n))
941 (if (math-expr-contains (car p) math-integ-var)
942 (setq bad t))))
943 (and which (not bad)
944 (let ((prime (if (= which 1) "'" (format "'%d" which))))
945 (and (string-match (concat prime "\\('['0-9]*\\|$\\)")
946 name)
947 (cons (intern
948 (concat
949 (substring name 0 (match-beginning 0))
950 (substring name (+ (match-beginning 0)
951 (length prime)))))
952 (cdr expr)))))))
953
954 ;; Try transformation methods (parts, substitutions).
955 (and (> math-integ-level 0)
956 (math-do-integral-methods expr))
957
958 ;; Try expanding the function's definition.
959 (let ((res (math-expand-formula expr)))
960 (and res
961 (math-integral res))))))
962
963 (defun math-sub-integration (expr &rest rest)
964 (or (if (or (not rest)
965 (and (< math-integ-level math-integral-limit)
966 (eq (car rest) math-integ-var)))
967 (math-integral expr)
968 (let ((res (apply math-old-integ expr rest)))
969 (and (or (= math-integ-level math-integral-limit)
970 (not (math-expr-calls res 'calcFunc-integ)))
971 res)))
972 (list 'calcFunc-integfailed expr)))
973
974 (defun math-do-integral-methods (expr)
975 (let ((so-far math-integ-var-list-list)
976 rat-in)
977
978 ;; Integration by substitution, for various likely sub-expressions.
979 ;; (In first pass, we look only for sub-exprs that are linear in X.)
980 (or (if math-enable-subst
981 (math-integ-try-substitutions expr)
982 (math-integ-try-linear-substitutions expr))
983
984 ;; If function has sines and cosines, try tan(x/2) substitution.
985 (and (let ((p (setq rat-in (math-expr-rational-in expr))))
986 (while (and p
987 (memq (car (car p)) '(calcFunc-sin
988 calcFunc-cos
989 calcFunc-tan))
990 (equal (nth 1 (car p)) math-integ-var))
991 (setq p (cdr p)))
992 (null p))
993 (or (and (math-integ-parts-easy expr)
994 (math-integ-try-parts expr t))
995 (math-integrate-by-good-substitution
996 expr (list 'calcFunc-tan (math-div math-integ-var 2)))))
997
998 ;; If function has sinh and cosh, try tanh(x/2) substitution.
999 (and (let ((p rat-in))
1000 (while (and p
1001 (memq (car (car p)) '(calcFunc-sinh
1002 calcFunc-cosh
1003 calcFunc-tanh
1004 calcFunc-exp))
1005 (equal (nth 1 (car p)) math-integ-var))
1006 (setq p (cdr p)))
1007 (null p))
1008 (or (and (math-integ-parts-easy expr)
1009 (math-integ-try-parts expr t))
1010 (math-integrate-by-good-substitution
1011 expr (list 'calcFunc-tanh (math-div math-integ-var 2)))))
1012
1013 ;; If function has square roots, try sin, tan, or sec substitution.
1014 (and (let ((p rat-in))
1015 (setq t1 nil)
1016 (while (and p
1017 (or (equal (car p) math-integ-var)
1018 (and (eq (car (car p)) 'calcFunc-sqrt)
1019 (setq t1 (math-is-polynomial
1020 (nth 1 (setq t2 (car p)))
1021 math-integ-var 2)))))
1022 (setq p (cdr p)))
1023 (and (null p) t1))
1024 (if (cdr (cdr t1))
1025 (if (math-guess-if-neg (nth 2 t1))
1026 (let* ((c (math-sqrt (math-neg (nth 2 t1))))
1027 (d (math-div (nth 1 t1) (math-mul -2 c)))
1028 (a (math-sqrt (math-add (car t1) (math-sqr d)))))
1029 (math-integrate-by-good-substitution
1030 expr (list 'calcFunc-arcsin
1031 (math-div-thru
1032 (math-add (math-mul c math-integ-var) d)
1033 a))))
1034 (let* ((c (math-sqrt (nth 2 t1)))
1035 (d (math-div (nth 1 t1) (math-mul 2 c)))
1036 (aa (math-sub (car t1) (math-sqr d))))
1037 (if (and nil (not (and (eq d 0) (eq c 1))))
1038 (math-integrate-by-good-substitution
1039 expr (math-add (math-mul c math-integ-var) d))
1040 (if (math-guess-if-neg aa)
1041 (math-integrate-by-good-substitution
1042 expr (list 'calcFunc-arccosh
1043 (math-div-thru
1044 (math-add (math-mul c math-integ-var)
1045 d)
1046 (math-sqrt (math-neg aa)))))
1047 (math-integrate-by-good-substitution
1048 expr (list 'calcFunc-arcsinh
1049 (math-div-thru
1050 (math-add (math-mul c math-integ-var)
1051 d)
1052 (math-sqrt aa))))))))
1053 (math-integrate-by-good-substitution expr t2)) )
1054
1055 ;; Try integration by parts.
1056 (math-integ-try-parts expr)
1057
1058 ;; Give up.
1059 nil)))
1060
1061 (defun math-integ-parts-easy (expr)
1062 (cond ((Math-primp expr) t)
1063 ((memq (car expr) '(+ - *))
1064 (and (math-integ-parts-easy (nth 1 expr))
1065 (math-integ-parts-easy (nth 2 expr))))
1066 ((eq (car expr) '/)
1067 (and (math-integ-parts-easy (nth 1 expr))
1068 (math-atomic-factorp (nth 2 expr))))
1069 ((eq (car expr) '^)
1070 (and (natnump (nth 2 expr))
1071 (math-integ-parts-easy (nth 1 expr))))
1072 ((eq (car expr) 'neg)
1073 (math-integ-parts-easy (nth 1 expr)))
1074 (t t)))
1075
1076 (defun math-integ-try-parts (expr &optional math-good-parts)
1077 ;; Integration by parts:
1078 ;; integ(f(x) g(x),x) = f(x) h(x) - integ(h(x) f'(x),x)
1079 ;; where h(x) = integ(g(x),x).
1080 (or (let ((exp (calcFunc-expand expr)))
1081 (and (not (equal exp expr))
1082 (math-integral exp)))
1083 (and (eq (car expr) '*)
1084 (let ((first-bad (or (math-polynomial-p (nth 1 expr)
1085 math-integ-var)
1086 (equal (nth 2 expr) math-prev-parts-v))))
1087 (or (and first-bad ; so try this one first
1088 (math-integrate-by-parts (nth 1 expr) (nth 2 expr)))
1089 (math-integrate-by-parts (nth 2 expr) (nth 1 expr))
1090 (and (not first-bad)
1091 (math-integrate-by-parts (nth 1 expr) (nth 2 expr))))))
1092 (and (eq (car expr) '/)
1093 (math-expr-contains (nth 1 expr) math-integ-var)
1094 (let ((recip (math-div 1 (nth 2 expr))))
1095 (or (math-integrate-by-parts (nth 1 expr) recip)
1096 (math-integrate-by-parts recip (nth 1 expr)))))
1097 (and (eq (car expr) '^)
1098 (math-integrate-by-parts (math-pow (nth 1 expr)
1099 (math-sub (nth 2 expr) 1))
1100 (nth 1 expr)))))
1101
1102 (defun math-integrate-by-parts (u vprime)
1103 (let ((math-integ-level (if (or math-good-parts
1104 (math-polynomial-p u math-integ-var))
1105 math-integ-level
1106 (1- math-integ-level)))
1107 (math-doing-parts t)
1108 v temp)
1109 (and (>= math-integ-level 0)
1110 (unwind-protect
1111 (progn
1112 (setcar (cdr cur-record) 'parts)
1113 (math-tracing-integral "Integrating by parts, u = "
1114 (math-format-value u 1000)
1115 ", v' = "
1116 (math-format-value vprime 1000)
1117 "\n")
1118 (and (setq v (math-integral vprime))
1119 (setq temp (calcFunc-deriv u math-integ-var nil t))
1120 (setq temp (let ((math-prev-parts-v v))
1121 (math-integral (math-mul v temp) 'yes)))
1122 (setq temp (math-sub (math-mul u v) temp))
1123 (if (eq (nth 1 cur-record) 'parts)
1124 (calcFunc-expand temp)
1125 (setq v (list 'var 'PARTS cur-record)
1126 var-thing (list 'vec (math-sub v temp) v)
1127 temp (let (calc-next-why)
1128 (math-solve-for (math-sub v temp) 0 v nil)))
1129 (and temp (not (integerp temp))
1130 (math-simplify-extended temp)))))
1131 (setcar (cdr cur-record) 'busy)))))
1132
1133 ;;; This tries two different formulations, hoping the algebraic simplifier
1134 ;;; will be strong enough to handle at least one.
1135 (defun math-integrate-by-substitution (expr u &optional user uinv uinvprime)
1136 (and (> math-integ-level 0)
1137 (let ((math-integ-level (max (- math-integ-level 2) 0)))
1138 (math-integrate-by-good-substitution expr u user uinv uinvprime))))
1139
1140 (defun math-integrate-by-good-substitution (expr u &optional user
1141 uinv uinvprime)
1142 (let ((math-living-dangerously t)
1143 deriv temp)
1144 (and (setq uinv (if uinv
1145 (math-expr-subst uinv math-integ-var
1146 math-integ-var-2)
1147 (let (calc-next-why)
1148 (math-solve-for u
1149 math-integ-var-2
1150 math-integ-var nil))))
1151 (progn
1152 (math-tracing-integral "Integrating by substitution, u = "
1153 (math-format-value u 1000)
1154 "\n")
1155 (or (and (setq deriv (calcFunc-deriv u
1156 math-integ-var nil
1157 (not user)))
1158 (setq temp (math-integral (math-expr-subst
1159 (math-expr-subst
1160 (math-expr-subst
1161 (math-div expr deriv)
1162 u
1163 math-integ-var-2)
1164 math-integ-var
1165 uinv)
1166 math-integ-var-2
1167 math-integ-var)
1168 'yes)))
1169 (and (setq deriv (or uinvprime
1170 (calcFunc-deriv uinv
1171 math-integ-var-2
1172 math-integ-var
1173 (not user))))
1174 (setq temp (math-integral (math-mul
1175 (math-expr-subst
1176 (math-expr-subst
1177 (math-expr-subst
1178 expr
1179 u
1180 math-integ-var-2)
1181 math-integ-var
1182 uinv)
1183 math-integ-var-2
1184 math-integ-var)
1185 deriv)
1186 'yes)))))
1187 (math-simplify-extended
1188 (math-expr-subst temp math-integ-var u)))))
1189
1190 ;;; Look for substitutions of the form u = a x + b.
1191 (defun math-integ-try-linear-substitutions (sub-expr)
1192 (and (not (Math-primp sub-expr))
1193 (or (and (not (memq (car sub-expr) '(+ - * / neg)))
1194 (not (and (eq (car sub-expr) '^)
1195 (integerp (nth 2 sub-expr))))
1196 (math-expr-contains sub-expr math-integ-var)
1197 (let ((res nil))
1198 (while (and (setq sub-expr (cdr sub-expr))
1199 (or (not (math-linear-in (car sub-expr)
1200 math-integ-var))
1201 (assoc (car sub-expr) so-far)
1202 (progn
1203 (setq so-far (cons (list (car sub-expr))
1204 so-far))
1205 (not (setq res
1206 (math-integrate-by-substitution
1207 expr (car sub-expr))))))))
1208 res))
1209 (let ((res nil))
1210 (while (and (setq sub-expr (cdr sub-expr))
1211 (not (setq res (math-integ-try-linear-substitutions
1212 (car sub-expr))))))
1213 res))))
1214
1215 ;;; Recursively try different substitutions based on various sub-expressions.
1216 (defun math-integ-try-substitutions (sub-expr &optional allow-rat)
1217 (and (not (Math-primp sub-expr))
1218 (not (assoc sub-expr so-far))
1219 (math-expr-contains sub-expr math-integ-var)
1220 (or (and (if (and (not (memq (car sub-expr) '(+ - * / neg)))
1221 (not (and (eq (car sub-expr) '^)
1222 (integerp (nth 2 sub-expr)))))
1223 (setq allow-rat t)
1224 (prog1 allow-rat (setq allow-rat nil)))
1225 (not (eq sub-expr expr))
1226 (or (math-integrate-by-substitution expr sub-expr)
1227 (and (eq (car sub-expr) '^)
1228 (integerp (nth 2 sub-expr))
1229 (< (nth 2 sub-expr) 0)
1230 (math-integ-try-substitutions
1231 (math-pow (nth 1 sub-expr) (- (nth 2 sub-expr)))
1232 t))))
1233 (let ((res nil))
1234 (setq so-far (cons (list sub-expr) so-far))
1235 (while (and (setq sub-expr (cdr sub-expr))
1236 (not (setq res (math-integ-try-substitutions
1237 (car sub-expr) allow-rat)))))
1238 res))))
1239
1240 (defun math-expr-rational-in (expr)
1241 (let ((parts nil))
1242 (math-expr-rational-in-rec expr)
1243 (mapcar 'car parts)))
1244
1245 (defun math-expr-rational-in-rec (expr)
1246 (cond ((Math-primp expr)
1247 (and (equal expr math-integ-var)
1248 (not (assoc expr parts))
1249 (setq parts (cons (list expr) parts))))
1250 ((or (memq (car expr) '(+ - * / neg))
1251 (and (eq (car expr) '^) (integerp (nth 2 expr))))
1252 (math-expr-rational-in-rec (nth 1 expr))
1253 (and (nth 2 expr) (math-expr-rational-in-rec (nth 2 expr))))
1254 ((and (eq (car expr) '^)
1255 (eq (math-quarter-integer (nth 2 expr)) 2))
1256 (math-expr-rational-in-rec (list 'calcFunc-sqrt (nth 1 expr))))
1257 (t
1258 (and (not (assoc expr parts))
1259 (math-expr-contains expr math-integ-var)
1260 (setq parts (cons (list expr) parts))))))
1261
1262 (defun math-expr-calls (expr funcs &optional arg-contains)
1263 (if (consp expr)
1264 (if (or (memq (car expr) funcs)
1265 (and (eq (car expr) '^) (eq (car funcs) 'calcFunc-sqrt)
1266 (eq (math-quarter-integer (nth 2 expr)) 2)))
1267 (and (or (not arg-contains)
1268 (math-expr-contains expr arg-contains))
1269 expr)
1270 (and (not (Math-primp expr))
1271 (let ((res nil))
1272 (while (and (setq expr (cdr expr))
1273 (not (setq res (math-expr-calls
1274 (car expr) funcs arg-contains)))))
1275 res)))))
1276
1277 (defun math-fix-const-terms (expr except-vars)
1278 (cond ((not (math-expr-depends expr except-vars)) 0)
1279 ((Math-primp expr) expr)
1280 ((eq (car expr) '+)
1281 (math-add (math-fix-const-terms (nth 1 expr) except-vars)
1282 (math-fix-const-terms (nth 2 expr) except-vars)))
1283 ((eq (car expr) '-)
1284 (math-sub (math-fix-const-terms (nth 1 expr) except-vars)
1285 (math-fix-const-terms (nth 2 expr) except-vars)))
1286 (t expr)))
1287
1288 ;; Command for debugging the Calculator's symbolic integrator.
1289 (defun calc-dump-integral-cache (&optional arg)
1290 (interactive "P")
1291 (let ((buf (current-buffer)))
1292 (unwind-protect
1293 (let ((p math-integral-cache)
1294 cur-record)
1295 (display-buffer (get-buffer-create "*Integral Cache*"))
1296 (set-buffer (get-buffer "*Integral Cache*"))
1297 (erase-buffer)
1298 (while p
1299 (setq cur-record (car p))
1300 (or arg (math-replace-integral-parts cur-record))
1301 (insert (math-format-flat-expr (car cur-record) 0)
1302 " --> "
1303 (if (symbolp (nth 1 cur-record))
1304 (concat "(" (symbol-name (nth 1 cur-record)) ")")
1305 (math-format-flat-expr (nth 1 cur-record) 0))
1306 "\n")
1307 (setq p (cdr p)))
1308 (goto-char (point-min)))
1309 (set-buffer buf))))
1310
1311 (defun math-try-integral (expr)
1312 (let ((math-integ-level math-integral-limit)
1313 (math-integ-depth 0)
1314 (math-integ-msg "Working...done")
1315 (cur-record nil) ; a technicality
1316 (math-integrating t)
1317 (calc-prefer-frac t)
1318 (calc-symbolic-mode t)
1319 (has-rules (calc-has-rules 'var-IntegRules)))
1320 (or (math-integral expr 'yes)
1321 (and math-any-substs
1322 (setq math-enable-subst t)
1323 (math-integral expr 'yes))
1324 (and (> math-max-integral-limit math-integral-limit)
1325 (setq math-integral-limit math-max-integral-limit
1326 math-integ-level math-integral-limit)
1327 (math-integral expr 'yes)))))
1328
1329 (defun calcFunc-integ (expr var &optional low high)
1330 (cond
1331 ;; Do these even if the parts turn out not to be integrable.
1332 ((eq (car-safe expr) '+)
1333 (math-add (calcFunc-integ (nth 1 expr) var low high)
1334 (calcFunc-integ (nth 2 expr) var low high)))
1335 ((eq (car-safe expr) '-)
1336 (math-sub (calcFunc-integ (nth 1 expr) var low high)
1337 (calcFunc-integ (nth 2 expr) var low high)))
1338 ((eq (car-safe expr) 'neg)
1339 (math-neg (calcFunc-integ (nth 1 expr) var low high)))
1340 ((and (eq (car-safe expr) '*)
1341 (not (math-expr-contains (nth 1 expr) var)))
1342 (math-mul (nth 1 expr) (calcFunc-integ (nth 2 expr) var low high)))
1343 ((and (eq (car-safe expr) '*)
1344 (not (math-expr-contains (nth 2 expr) var)))
1345 (math-mul (calcFunc-integ (nth 1 expr) var low high) (nth 2 expr)))
1346 ((and (eq (car-safe expr) '/)
1347 (not (math-expr-contains (nth 1 expr) var))
1348 (not (math-equal-int (nth 1 expr) 1)))
1349 (math-mul (nth 1 expr)
1350 (calcFunc-integ (math-div 1 (nth 2 expr)) var low high)))
1351 ((and (eq (car-safe expr) '/)
1352 (not (math-expr-contains (nth 2 expr) var)))
1353 (math-div (calcFunc-integ (nth 1 expr) var low high) (nth 2 expr)))
1354 ((and (eq (car-safe expr) '/)
1355 (eq (car-safe (nth 1 expr)) '*)
1356 (not (math-expr-contains (nth 1 (nth 1 expr)) var)))
1357 (math-mul (nth 1 (nth 1 expr))
1358 (calcFunc-integ (math-div (nth 2 (nth 1 expr)) (nth 2 expr))
1359 var low high)))
1360 ((and (eq (car-safe expr) '/)
1361 (eq (car-safe (nth 1 expr)) '*)
1362 (not (math-expr-contains (nth 2 (nth 1 expr)) var)))
1363 (math-mul (nth 2 (nth 1 expr))
1364 (calcFunc-integ (math-div (nth 1 (nth 1 expr)) (nth 2 expr))
1365 var low high)))
1366 ((and (eq (car-safe expr) '/)
1367 (eq (car-safe (nth 2 expr)) '*)
1368 (not (math-expr-contains (nth 1 (nth 2 expr)) var)))
1369 (math-div (calcFunc-integ (math-div (nth 1 expr) (nth 2 (nth 2 expr)))
1370 var low high)
1371 (nth 1 (nth 2 expr))))
1372 ((and (eq (car-safe expr) '/)
1373 (eq (car-safe (nth 2 expr)) '*)
1374 (not (math-expr-contains (nth 2 (nth 2 expr)) var)))
1375 (math-div (calcFunc-integ (math-div (nth 1 expr) (nth 1 (nth 2 expr)))
1376 var low high)
1377 (nth 2 (nth 2 expr))))
1378 ((eq (car-safe expr) 'vec)
1379 (cons 'vec (mapcar (function (lambda (x) (calcFunc-integ x var low high)))
1380 (cdr expr))))
1381 (t
1382 (let ((state (list calc-angle-mode
1383 ;;calc-symbolic-mode
1384 ;;calc-prefer-frac
1385 calc-internal-prec
1386 (calc-var-value 'var-IntegRules)
1387 (calc-var-value 'var-IntegSimpRules))))
1388 (or (equal state math-integral-cache-state)
1389 (setq math-integral-cache-state state
1390 math-integral-cache nil)))
1391 (let* ((math-max-integral-limit (or (and (boundp 'var-IntegLimit)
1392 (natnump var-IntegLimit)
1393 var-IntegLimit)
1394 3))
1395 (math-integral-limit 1)
1396 (sexpr (math-expr-subst expr var math-integ-var))
1397 (trace-buffer (get-buffer "*Trace*"))
1398 (calc-language (if (eq calc-language 'big) nil calc-language))
1399 (math-any-substs t)
1400 (math-enable-subst nil)
1401 (math-prev-parts-v nil)
1402 (math-doing-parts nil)
1403 (math-good-parts nil)
1404 (res
1405 (if trace-buffer
1406 (let ((calcbuf (current-buffer))
1407 (calcwin (selected-window)))
1408 (unwind-protect
1409 (progn
1410 (if (get-buffer-window trace-buffer)
1411 (select-window (get-buffer-window trace-buffer)))
1412 (set-buffer trace-buffer)
1413 (goto-char (point-max))
1414 (or (assq 'scroll-stop (buffer-local-variables))
1415 (progn
1416 (make-local-variable 'scroll-step)
1417 (setq scroll-step 3)))
1418 (insert "\n\n\n")
1419 (set-buffer calcbuf)
1420 (math-try-integral sexpr))
1421 (select-window calcwin)
1422 (set-buffer calcbuf)))
1423 (math-try-integral sexpr))))
1424 (if res
1425 (progn
1426 (if (calc-has-rules 'var-IntegAfterRules)
1427 (setq res (math-rewrite res '(var IntegAfterRules
1428 var-IntegAfterRules))))
1429 (math-simplify
1430 (if (and low high)
1431 (math-sub (math-expr-subst res math-integ-var high)
1432 (math-expr-subst res math-integ-var low))
1433 (setq res (math-fix-const-terms res math-integ-vars))
1434 (if low
1435 (math-expr-subst res math-integ-var low)
1436 (math-expr-subst res math-integ-var var)))))
1437 (append (list 'calcFunc-integ expr var)
1438 (and low (list low))
1439 (and high (list high))))))))
1440
1441
1442 (math-defintegral calcFunc-inv
1443 (math-integral (math-div 1 u)))
1444
1445 (math-defintegral calcFunc-conj
1446 (let ((int (math-integral u)))
1447 (and int
1448 (list 'calcFunc-conj int))))
1449
1450 (math-defintegral calcFunc-deg
1451 (let ((int (math-integral u)))
1452 (and int
1453 (list 'calcFunc-deg int))))
1454
1455 (math-defintegral calcFunc-rad
1456 (let ((int (math-integral u)))
1457 (and int
1458 (list 'calcFunc-rad int))))
1459
1460 (math-defintegral calcFunc-re
1461 (let ((int (math-integral u)))
1462 (and int
1463 (list 'calcFunc-re int))))
1464
1465 (math-defintegral calcFunc-im
1466 (let ((int (math-integral u)))
1467 (and int
1468 (list 'calcFunc-im int))))
1469
1470 (math-defintegral calcFunc-sqrt
1471 (and (equal u math-integ-var)
1472 (math-mul '(frac 2 3)
1473 (list 'calcFunc-sqrt (math-pow u 3)))))
1474
1475 (math-defintegral calcFunc-exp
1476 (or (and (equal u math-integ-var)
1477 (list 'calcFunc-exp u))
1478 (let ((p (math-is-polynomial u math-integ-var 2)))
1479 (and (nth 2 p)
1480 (let ((sqa (math-sqrt (math-neg (nth 2 p)))))
1481 (math-div
1482 (math-mul
1483 (math-mul (math-div (list 'calcFunc-sqrt '(var pi var-pi))
1484 sqa)
1485 (math-normalize
1486 (list 'calcFunc-exp
1487 (math-div (math-sub (math-mul (car p)
1488 (nth 2 p))
1489 (math-div
1490 (math-sqr (nth 1 p))
1491 4))
1492 (nth 2 p)))))
1493 (list 'calcFunc-erf
1494 (math-sub (math-mul sqa math-integ-var)
1495 (math-div (nth 1 p) (math-mul 2 sqa)))))
1496 2))))))
1497
1498 (math-defintegral calcFunc-ln
1499 (or (and (equal u math-integ-var)
1500 (math-sub (math-mul u (list 'calcFunc-ln u)) u))
1501 (and (eq (car u) '*)
1502 (math-integral (math-add (list 'calcFunc-ln (nth 1 u))
1503 (list 'calcFunc-ln (nth 2 u)))))
1504 (and (eq (car u) '/)
1505 (math-integral (math-sub (list 'calcFunc-ln (nth 1 u))
1506 (list 'calcFunc-ln (nth 2 u)))))
1507 (and (eq (car u) '^)
1508 (math-integral (math-mul (nth 2 u)
1509 (list 'calcFunc-ln (nth 1 u)))))))
1510
1511 (math-defintegral calcFunc-log10
1512 (and (equal u math-integ-var)
1513 (math-sub (math-mul u (list 'calcFunc-ln u))
1514 (math-div u (list 'calcFunc-ln 10)))))
1515
1516 (math-defintegral-2 calcFunc-log
1517 (math-integral (math-div (list 'calcFunc-ln u)
1518 (list 'calcFunc-ln v))))
1519
1520 (math-defintegral calcFunc-sin
1521 (or (and (equal u math-integ-var)
1522 (math-neg (math-from-radians-2 (list 'calcFunc-cos u))))
1523 (and (nth 2 (math-is-polynomial u math-integ-var 2))
1524 (math-integral (math-to-exponentials (list 'calcFunc-sin u))))))
1525
1526 (math-defintegral calcFunc-cos
1527 (or (and (equal u math-integ-var)
1528 (math-from-radians-2 (list 'calcFunc-sin u)))
1529 (and (nth 2 (math-is-polynomial u math-integ-var 2))
1530 (math-integral (math-to-exponentials (list 'calcFunc-cos u))))))
1531
1532 (math-defintegral calcFunc-tan
1533 (and (equal u math-integ-var)
1534 (math-neg (math-from-radians-2
1535 (list 'calcFunc-ln (list 'calcFunc-cos u))))))
1536
1537 (math-defintegral calcFunc-arcsin
1538 (and (equal u math-integ-var)
1539 (math-add (math-mul u (list 'calcFunc-arcsin u))
1540 (math-from-radians-2
1541 (list 'calcFunc-sqrt (math-sub 1 (math-sqr u)))))))
1542
1543 (math-defintegral calcFunc-arccos
1544 (and (equal u math-integ-var)
1545 (math-sub (math-mul u (list 'calcFunc-arccos u))
1546 (math-from-radians-2
1547 (list 'calcFunc-sqrt (math-sub 1 (math-sqr u)))))))
1548
1549 (math-defintegral calcFunc-arctan
1550 (and (equal u math-integ-var)
1551 (math-sub (math-mul u (list 'calcFunc-arctan u))
1552 (math-from-radians-2
1553 (math-div (list 'calcFunc-ln (math-add 1 (math-sqr u)))
1554 2)))))
1555
1556 (math-defintegral calcFunc-sinh
1557 (and (equal u math-integ-var)
1558 (list 'calcFunc-cosh u)))
1559
1560 (math-defintegral calcFunc-cosh
1561 (and (equal u math-integ-var)
1562 (list 'calcFunc-sinh u)))
1563
1564 (math-defintegral calcFunc-tanh
1565 (and (equal u math-integ-var)
1566 (list 'calcFunc-ln (list 'calcFunc-cosh u))))
1567
1568 (math-defintegral calcFunc-arcsinh
1569 (and (equal u math-integ-var)
1570 (math-sub (math-mul u (list 'calcFunc-arcsinh u))
1571 (list 'calcFunc-sqrt (math-add (math-sqr u) 1)))))
1572
1573 (math-defintegral calcFunc-arccosh
1574 (and (equal u math-integ-var)
1575 (math-sub (math-mul u (list 'calcFunc-arccosh u))
1576 (list 'calcFunc-sqrt (math-sub 1 (math-sqr u))))))
1577
1578 (math-defintegral calcFunc-arctanh
1579 (and (equal u math-integ-var)
1580 (math-sub (math-mul u (list 'calcFunc-arctan u))
1581 (math-div (list 'calcFunc-ln
1582 (math-add 1 (math-sqr u)))
1583 2))))
1584
1585 ;;; (Ax + B) / (ax^2 + bx + c)^n forms.
1586 (math-defintegral-2 /
1587 (math-integral-rational-funcs u v))
1588
1589 (defun math-integral-rational-funcs (u v)
1590 (let ((pu (math-is-polynomial u math-integ-var 1))
1591 (vpow 1) pv)
1592 (and pu
1593 (catch 'int-rat
1594 (if (and (eq (car-safe v) '^) (natnump (nth 2 v)))
1595 (setq vpow (nth 2 v)
1596 v (nth 1 v)))
1597 (and (setq pv (math-is-polynomial v math-integ-var 2))
1598 (let ((int (math-mul-thru
1599 (car pu)
1600 (math-integral-q02 (car pv) (nth 1 pv)
1601 (nth 2 pv) v vpow))))
1602 (if (cdr pu)
1603 (setq int (math-add int
1604 (math-mul-thru
1605 (nth 1 pu)
1606 (math-integral-q12
1607 (car pv) (nth 1 pv)
1608 (nth 2 pv) v vpow)))))
1609 int))))))
1610
1611 (defun math-integral-q12 (a b c v vpow)
1612 (let (q)
1613 (cond ((not c)
1614 (cond ((= vpow 1)
1615 (math-sub (math-div math-integ-var b)
1616 (math-mul (math-div a (math-sqr b))
1617 (list 'calcFunc-ln v))))
1618 ((= vpow 2)
1619 (math-div (math-add (list 'calcFunc-ln v)
1620 (math-div a v))
1621 (math-sqr b)))
1622 (t
1623 (let ((nm1 (math-sub vpow 1))
1624 (nm2 (math-sub vpow 2)))
1625 (math-div (math-sub
1626 (math-div a (math-mul nm1 (math-pow v nm1)))
1627 (math-div 1 (math-mul nm2 (math-pow v nm2))))
1628 (math-sqr b))))))
1629 ((math-zerop
1630 (setq q (math-sub (math-mul 4 (math-mul a c)) (math-sqr b))))
1631 (let ((part (math-div b (math-mul 2 c))))
1632 (math-mul-thru (math-pow c vpow)
1633 (math-integral-q12 part 1 nil
1634 (math-add math-integ-var part)
1635 (* vpow 2)))))
1636 ((= vpow 1)
1637 (and (math-ratp q) (math-negp q)
1638 (let ((calc-symbolic-mode t))
1639 (math-ratp (math-sqrt (math-neg q))))
1640 (throw 'int-rat nil)) ; should have used calcFunc-apart first
1641 (math-sub (math-div (list 'calcFunc-ln v) (math-mul 2 c))
1642 (math-mul-thru (math-div b (math-mul 2 c))
1643 (math-integral-q02 a b c v 1))))
1644 (t
1645 (let ((n (1- vpow)))
1646 (math-sub (math-neg (math-div
1647 (math-add (math-mul b math-integ-var)
1648 (math-mul 2 a))
1649 (math-mul n (math-mul q (math-pow v n)))))
1650 (math-mul-thru (math-div (math-mul b (1- (* 2 n)))
1651 (math-mul n q))
1652 (math-integral-q02 a b c v n))))))))
1653
1654 (defun math-integral-q02 (a b c v vpow)
1655 (let (q rq part)
1656 (cond ((not c)
1657 (cond ((= vpow 1)
1658 (math-div (list 'calcFunc-ln v) b))
1659 (t
1660 (math-div (math-pow v (- 1 vpow))
1661 (math-mul (- 1 vpow) b)))))
1662 ((math-zerop
1663 (setq q (math-sub (math-mul 4 (math-mul a c)) (math-sqr b))))
1664 (let ((part (math-div b (math-mul 2 c))))
1665 (math-mul-thru (math-pow c vpow)
1666 (math-integral-q02 part 1 nil
1667 (math-add math-integ-var part)
1668 (* vpow 2)))))
1669 ((progn
1670 (setq part (math-add (math-mul 2 (math-mul c math-integ-var)) b))
1671 (> vpow 1))
1672 (let ((n (1- vpow)))
1673 (math-add (math-div part (math-mul n (math-mul q (math-pow v n))))
1674 (math-mul-thru (math-div (math-mul (- (* 4 n) 2) c)
1675 (math-mul n q))
1676 (math-integral-q02 a b c v n)))))
1677 ((math-guess-if-neg q)
1678 (setq rq (list 'calcFunc-sqrt (math-neg q)))
1679 ;;(math-div-thru (list 'calcFunc-ln
1680 ;; (math-div (math-sub part rq)
1681 ;; (math-add part rq)))
1682 ;; rq)
1683 (math-div (math-mul -2 (list 'calcFunc-arctanh
1684 (math-div part rq)))
1685 rq))
1686 (t
1687 (setq rq (list 'calcFunc-sqrt q))
1688 (math-div (math-mul 2 (math-to-radians-2
1689 (list 'calcFunc-arctan
1690 (math-div part rq))))
1691 rq)))))
1692
1693
1694 (math-defintegral calcFunc-erf
1695 (and (equal u math-integ-var)
1696 (math-add (math-mul u (list 'calcFunc-erf u))
1697 (math-div 1 (math-mul (list 'calcFunc-exp (math-sqr u))
1698 (list 'calcFunc-sqrt
1699 '(var pi var-pi)))))))
1700
1701 (math-defintegral calcFunc-erfc
1702 (and (equal u math-integ-var)
1703 (math-sub (math-mul u (list 'calcFunc-erfc u))
1704 (math-div 1 (math-mul (list 'calcFunc-exp (math-sqr u))
1705 (list 'calcFunc-sqrt
1706 '(var pi var-pi)))))))
1707
1708
1709
1710
1711 (defvar math-tabulate-initial nil)
1712 (defvar math-tabulate-function nil)
1713 (defun calcFunc-table (expr var &optional low high step)
1714 (or low (setq low '(neg (var inf var-inf)) high '(var inf var-inf)))
1715 (or high (setq high low low 1))
1716 (and (or (math-infinitep low) (math-infinitep high))
1717 (not step)
1718 (math-scan-for-limits expr))
1719 (and step (math-zerop step) (math-reject-arg step 'nonzerop))
1720 (let ((known (+ (if (Math-objectp low) 1 0)
1721 (if (Math-objectp high) 1 0)
1722 (if (or (null step) (Math-objectp step)) 1 0)))
1723 (count '(var inf var-inf))
1724 vec)
1725 (or (= known 2) ; handy optimization
1726 (equal high '(var inf var-inf))
1727 (progn
1728 (setq count (math-div (math-sub high low) (or step 1)))
1729 (or (Math-objectp count)
1730 (setq count (math-simplify count)))
1731 (if (Math-messy-integerp count)
1732 (setq count (math-trunc count)))))
1733 (if (Math-negp count)
1734 (setq count -1))
1735 (if (integerp count)
1736 (let ((var-DUMMY nil)
1737 (vec math-tabulate-initial)
1738 (math-working-step-2 (1+ count))
1739 (math-working-step 0))
1740 (setq expr (math-evaluate-expr
1741 (math-expr-subst expr var '(var DUMMY var-DUMMY))))
1742 (while (>= count 0)
1743 (setq math-working-step (1+ math-working-step)
1744 var-DUMMY low
1745 vec (cond ((eq math-tabulate-function 'calcFunc-sum)
1746 (math-add vec (math-evaluate-expr expr)))
1747 ((eq math-tabulate-function 'calcFunc-prod)
1748 (math-mul vec (math-evaluate-expr expr)))
1749 (t
1750 (cons (math-evaluate-expr expr) vec)))
1751 low (math-add low (or step 1))
1752 count (1- count)))
1753 (if math-tabulate-function
1754 vec
1755 (cons 'vec (nreverse vec))))
1756 (if (Math-integerp count)
1757 (calc-record-why 'fixnump high)
1758 (if (Math-num-integerp low)
1759 (if (Math-num-integerp high)
1760 (calc-record-why 'integerp step)
1761 (calc-record-why 'integerp high))
1762 (calc-record-why 'integerp low)))
1763 (append (list (or math-tabulate-function 'calcFunc-table)
1764 expr var)
1765 (and (not (and (equal low '(neg (var inf var-inf)))
1766 (equal high '(var inf var-inf))))
1767 (list low high))
1768 (and step (list step))))))
1769
1770 (defun math-scan-for-limits (x)
1771 (cond ((Math-primp x))
1772 ((and (eq (car x) 'calcFunc-subscr)
1773 (Math-vectorp (nth 1 x))
1774 (math-expr-contains (nth 2 x) var))
1775 (let* ((calc-next-why nil)
1776 (low-val (math-solve-for (nth 2 x) 1 var nil))
1777 (high-val (math-solve-for (nth 2 x) (1- (length (nth 1 x)))
1778 var nil))
1779 temp)
1780 (and low-val (math-realp low-val)
1781 high-val (math-realp high-val))
1782 (and (Math-lessp high-val low-val)
1783 (setq temp low-val low-val high-val high-val temp))
1784 (setq low (math-max low (math-ceiling low-val))
1785 high (math-min high (math-floor high-val)))))
1786 (t
1787 (while (setq x (cdr x))
1788 (math-scan-for-limits (car x))))))
1789
1790
1791 (defvar math-disable-sums nil)
1792 (defun calcFunc-sum (expr var &optional low high step)
1793 (if math-disable-sums (math-reject-arg))
1794 (let* ((res (let* ((calc-internal-prec (+ calc-internal-prec 2)))
1795 (math-sum-rec expr var low high step)))
1796 (math-disable-sums t))
1797 (math-normalize res)))
1798
1799 (defun math-sum-rec (expr var &optional low high step)
1800 (or low (setq low '(neg (var inf var-inf)) high '(var inf var-inf)))
1801 (and low (not high) (setq high low low 1))
1802 (let (t1 t2 val)
1803 (setq val
1804 (cond
1805 ((not (math-expr-contains expr var))
1806 (math-mul expr (math-add (math-div (math-sub high low) (or step 1))
1807 1)))
1808 ((and step (not (math-equal-int step 1)))
1809 (if (math-negp step)
1810 (math-sum-rec expr var high low (math-neg step))
1811 (let ((lo (math-simplify (math-div low step))))
1812 (if (math-known-num-integerp lo)
1813 (math-sum-rec (math-normalize
1814 (math-expr-subst expr var
1815 (math-mul step var)))
1816 var lo (math-simplify (math-div high step)))
1817 (math-sum-rec (math-normalize
1818 (math-expr-subst expr var
1819 (math-add (math-mul step var)
1820 low)))
1821 var 0
1822 (math-simplify (math-div (math-sub high low)
1823 step)))))))
1824 ((memq (setq t1 (math-compare low high)) '(0 1))
1825 (if (eq t1 0)
1826 (math-expr-subst expr var low)
1827 0))
1828 ((setq t1 (math-is-polynomial expr var 20))
1829 (let ((poly nil)
1830 (n 0))
1831 (while t1
1832 (setq poly (math-poly-mix poly 1
1833 (math-sum-integer-power n) (car t1))
1834 n (1+ n)
1835 t1 (cdr t1)))
1836 (setq n (math-build-polynomial-expr poly high))
1837 (if (memq low '(0 1))
1838 n
1839 (math-sub n (math-build-polynomial-expr poly
1840 (math-sub low 1))))))
1841 ((and (memq (car expr) '(+ -))
1842 (setq t1 (math-sum-rec (nth 1 expr) var low high)
1843 t2 (math-sum-rec (nth 2 expr) var low high))
1844 (not (and (math-expr-calls t1 '(calcFunc-sum))
1845 (math-expr-calls t2 '(calcFunc-sum)))))
1846 (list (car expr) t1 t2))
1847 ((and (eq (car expr) '*)
1848 (setq t1 (math-sum-const-factors expr var)))
1849 (math-mul (car t1) (math-sum-rec (cdr t1) var low high)))
1850 ((and (eq (car expr) '*) (memq (car-safe (nth 1 expr)) '(+ -)))
1851 (math-sum-rec (math-add-or-sub (math-mul (nth 1 (nth 1 expr))
1852 (nth 2 expr))
1853 (math-mul (nth 2 (nth 1 expr))
1854 (nth 2 expr))
1855 nil (eq (car (nth 1 expr)) '-))
1856 var low high))
1857 ((and (eq (car expr) '*) (memq (car-safe (nth 2 expr)) '(+ -)))
1858 (math-sum-rec (math-add-or-sub (math-mul (nth 1 expr)
1859 (nth 1 (nth 2 expr)))
1860 (math-mul (nth 1 expr)
1861 (nth 2 (nth 2 expr)))
1862 nil (eq (car (nth 2 expr)) '-))
1863 var low high))
1864 ((and (eq (car expr) '/)
1865 (not (math-primp (nth 1 expr)))
1866 (setq t1 (math-sum-const-factors (nth 1 expr) var)))
1867 (math-mul (car t1)
1868 (math-sum-rec (math-div (cdr t1) (nth 2 expr))
1869 var low high)))
1870 ((and (eq (car expr) '/)
1871 (setq t1 (math-sum-const-factors (nth 2 expr) var)))
1872 (math-div (math-sum-rec (math-div (nth 1 expr) (cdr t1))
1873 var low high)
1874 (car t1)))
1875 ((eq (car expr) 'neg)
1876 (math-neg (math-sum-rec (nth 1 expr) var low high)))
1877 ((and (eq (car expr) '^)
1878 (not (math-expr-contains (nth 1 expr) var))
1879 (setq t1 (math-is-polynomial (nth 2 expr) var 1)))
1880 (let ((x (math-pow (nth 1 expr) (nth 1 t1))))
1881 (math-div (math-mul (math-sub (math-pow x (math-add 1 high))
1882 (math-pow x low))
1883 (math-pow (nth 1 expr) (car t1)))
1884 (math-sub x 1))))
1885 ((and (setq t1 (math-to-exponentials expr))
1886 (setq t1 (math-sum-rec t1 var low high))
1887 (not (math-expr-calls t1 '(calcFunc-sum))))
1888 (math-to-exps t1))
1889 ((memq (car expr) '(calcFunc-ln calcFunc-log10))
1890 (list (car expr) (calcFunc-prod (nth 1 expr) var low high)))
1891 ((and (eq (car expr) 'calcFunc-log)
1892 (= (length expr) 3)
1893 (not (math-expr-contains (nth 2 expr) var)))
1894 (list 'calcFunc-log
1895 (calcFunc-prod (nth 1 expr) var low high)
1896 (nth 2 expr)))))
1897 (if (equal val '(var nan var-nan)) (setq val nil))
1898 (or val
1899 (let* ((math-tabulate-initial 0)
1900 (math-tabulate-function 'calcFunc-sum))
1901 (calcFunc-table expr var low high)))))
1902
1903 (defun calcFunc-asum (expr var low &optional high step no-mul-flag)
1904 (or high (setq high low low 1))
1905 (if (and step (not (math-equal-int step 1)))
1906 (if (math-negp step)
1907 (math-mul (math-pow -1 low)
1908 (calcFunc-asum expr var high low (math-neg step) t))
1909 (let ((lo (math-simplify (math-div low step))))
1910 (if (math-num-integerp lo)
1911 (calcFunc-asum (math-normalize
1912 (math-expr-subst expr var
1913 (math-mul step var)))
1914 var lo (math-simplify (math-div high step)))
1915 (calcFunc-asum (math-normalize
1916 (math-expr-subst expr var
1917 (math-add (math-mul step var)
1918 low)))
1919 var 0
1920 (math-simplify (math-div (math-sub high low)
1921 step))))))
1922 (math-mul (if no-mul-flag 1 (math-pow -1 low))
1923 (calcFunc-sum (math-mul (math-pow -1 var) expr) var low high))))
1924
1925 (defun math-sum-const-factors (expr var)
1926 (let ((const nil)
1927 (not-const nil)
1928 (p expr))
1929 (while (eq (car-safe p) '*)
1930 (if (math-expr-contains (nth 1 p) var)
1931 (setq not-const (cons (nth 1 p) not-const))
1932 (setq const (cons (nth 1 p) const)))
1933 (setq p (nth 2 p)))
1934 (if (math-expr-contains p var)
1935 (setq not-const (cons p not-const))
1936 (setq const (cons p const)))
1937 (and const
1938 (cons (let ((temp (car const)))
1939 (while (setq const (cdr const))
1940 (setq temp (list '* (car const) temp)))
1941 temp)
1942 (let ((temp (or (car not-const) 1)))
1943 (while (setq not-const (cdr not-const))
1944 (setq temp (list '* (car not-const) temp)))
1945 temp)))))
1946
1947 (defvar math-sum-int-pow-cache (list '(0 1)))
1948 ;; Following is from CRC Math Tables, 27th ed, pp. 52-53.
1949 (defun math-sum-integer-power (pow)
1950 (let ((calc-prefer-frac t)
1951 (n (length math-sum-int-pow-cache)))
1952 (while (<= n pow)
1953 (let* ((new (list 0 0))
1954 (lin new)
1955 (pp (cdr (nth (1- n) math-sum-int-pow-cache)))
1956 (p 2)
1957 (sum 0)
1958 q)
1959 (while pp
1960 (setq q (math-div (car pp) p)
1961 new (cons (math-mul q n) new)
1962 sum (math-add sum q)
1963 p (1+ p)
1964 pp (cdr pp)))
1965 (setcar lin (math-sub 1 (math-mul n sum)))
1966 (setq math-sum-int-pow-cache
1967 (nconc math-sum-int-pow-cache (list (nreverse new)))
1968 n (1+ n))))
1969 (nth pow math-sum-int-pow-cache)))
1970
1971 (defun math-to-exponentials (expr)
1972 (and (consp expr)
1973 (= (length expr) 2)
1974 (let ((x (nth 1 expr))
1975 (pi (if calc-symbolic-mode '(var pi var-pi) (math-pi)))
1976 (i (if calc-symbolic-mode '(var i var-i) '(cplx 0 1))))
1977 (cond ((eq (car expr) 'calcFunc-exp)
1978 (list '^ '(var e var-e) x))
1979 ((eq (car expr) 'calcFunc-sin)
1980 (or (eq calc-angle-mode 'rad)
1981 (setq x (list '/ (list '* x pi) 180)))
1982 (list '/ (list '-
1983 (list '^ '(var e var-e) (list '* x i))
1984 (list '^ '(var e var-e)
1985 (list 'neg (list '* x i))))
1986 (list '* 2 i)))
1987 ((eq (car expr) 'calcFunc-cos)
1988 (or (eq calc-angle-mode 'rad)
1989 (setq x (list '/ (list '* x pi) 180)))
1990 (list '/ (list '+
1991 (list '^ '(var e var-e)
1992 (list '* x i))
1993 (list '^ '(var e var-e)
1994 (list 'neg (list '* x i))))
1995 2))
1996 ((eq (car expr) 'calcFunc-sinh)
1997 (list '/ (list '-
1998 (list '^ '(var e var-e) x)
1999 (list '^ '(var e var-e) (list 'neg x)))
2000 2))
2001 ((eq (car expr) 'calcFunc-cosh)
2002 (list '/ (list '+
2003 (list '^ '(var e var-e) x)
2004 (list '^ '(var e var-e) (list 'neg x)))
2005 2))
2006 (t nil)))))
2007
2008 (defun math-to-exps (expr)
2009 (cond (calc-symbolic-mode expr)
2010 ((Math-primp expr)
2011 (if (equal expr '(var e var-e)) (math-e) expr))
2012 ((and (eq (car expr) '^)
2013 (equal (nth 1 expr) '(var e var-e)))
2014 (list 'calcFunc-exp (nth 2 expr)))
2015 (t
2016 (cons (car expr) (mapcar 'math-to-exps (cdr expr))))))
2017
2018
2019 (defvar math-disable-prods nil)
2020 (defun calcFunc-prod (expr var &optional low high step)
2021 (if math-disable-prods (math-reject-arg))
2022 (let* ((res (let* ((calc-internal-prec (+ calc-internal-prec 2)))
2023 (math-prod-rec expr var low high step)))
2024 (math-disable-prods t))
2025 (math-normalize res)))
2026
2027 (defun math-prod-rec (expr var &optional low high step)
2028 (or low (setq low '(neg (var inf var-inf)) high '(var inf var-inf)))
2029 (and low (not high) (setq high '(var inf var-inf)))
2030 (let (t1 t2 t3 val)
2031 (setq val
2032 (cond
2033 ((not (math-expr-contains expr var))
2034 (math-pow expr (math-add (math-div (math-sub high low) (or step 1))
2035 1)))
2036 ((and step (not (math-equal-int step 1)))
2037 (if (math-negp step)
2038 (math-prod-rec expr var high low (math-neg step))
2039 (let ((lo (math-simplify (math-div low step))))
2040 (if (math-known-num-integerp lo)
2041 (math-prod-rec (math-normalize
2042 (math-expr-subst expr var
2043 (math-mul step var)))
2044 var lo (math-simplify (math-div high step)))
2045 (math-prod-rec (math-normalize
2046 (math-expr-subst expr var
2047 (math-add (math-mul step
2048 var)
2049 low)))
2050 var 0
2051 (math-simplify (math-div (math-sub high low)
2052 step)))))))
2053 ((and (memq (car expr) '(* /))
2054 (setq t1 (math-prod-rec (nth 1 expr) var low high)
2055 t2 (math-prod-rec (nth 2 expr) var low high))
2056 (not (and (math-expr-calls t1 '(calcFunc-prod))
2057 (math-expr-calls t2 '(calcFunc-prod)))))
2058 (list (car expr) t1 t2))
2059 ((and (eq (car expr) '^)
2060 (not (math-expr-contains (nth 2 expr) var)))
2061 (math-pow (math-prod-rec (nth 1 expr) var low high)
2062 (nth 2 expr)))
2063 ((and (eq (car expr) '^)
2064 (not (math-expr-contains (nth 1 expr) var)))
2065 (math-pow (nth 1 expr)
2066 (calcFunc-sum (nth 2 expr) var low high)))
2067 ((eq (car expr) 'sqrt)
2068 (math-normalize (list 'calcFunc-sqrt
2069 (list 'calcFunc-prod (nth 1 expr)
2070 var low high))))
2071 ((eq (car expr) 'neg)
2072 (math-mul (math-pow -1 (math-add (math-sub high low) 1))
2073 (math-prod-rec (nth 1 expr) var low high)))
2074 ((eq (car expr) 'calcFunc-exp)
2075 (list 'calcFunc-exp (calcFunc-sum (nth 1 expr) var low high)))
2076 ((and (setq t1 (math-is-polynomial expr var 1))
2077 (setq t2
2078 (cond
2079 ((or (and (math-equal-int (nth 1 t1) 1)
2080 (setq low (math-simplify
2081 (math-add low (car t1)))
2082 high (math-simplify
2083 (math-add high (car t1)))))
2084 (and (math-equal-int (nth 1 t1) -1)
2085 (setq t2 low
2086 low (math-simplify
2087 (math-sub (car t1) high))
2088 high (math-simplify
2089 (math-sub (car t1) t2)))))
2090 (if (or (math-zerop low) (math-zerop high))
2091 0
2092 (if (and (or (math-negp low) (math-negp high))
2093 (or (math-num-integerp low)
2094 (math-num-integerp high)))
2095 (if (math-posp high)
2096 0
2097 (math-mul (math-pow -1
2098 (math-add
2099 (math-add low high) 1))
2100 (list '/
2101 (list 'calcFunc-fact
2102 (math-neg low))
2103 (list 'calcFunc-fact
2104 (math-sub -1 high)))))
2105 (list '/
2106 (list 'calcFunc-fact high)
2107 (list 'calcFunc-fact (math-sub low 1))))))
2108 ((and (or (and (math-equal-int (nth 1 t1) 2)
2109 (setq t2 (math-simplify
2110 (math-add (math-mul low 2)
2111 (car t1)))
2112 t3 (math-simplify
2113 (math-add (math-mul high 2)
2114 (car t1)))))
2115 (and (math-equal-int (nth 1 t1) -2)
2116 (setq t2 (math-simplify
2117 (math-sub (car t1)
2118 (math-mul high 2)))
2119 t3 (math-simplify
2120 (math-sub (car t1)
2121 (math-mul low
2122 2))))))
2123 (or (math-integerp t2)
2124 (and (math-messy-integerp t2)
2125 (setq t2 (math-trunc t2)))
2126 (math-integerp t3)
2127 (and (math-messy-integerp t3)
2128 (setq t3 (math-trunc t3)))))
2129 (if (or (math-zerop t2) (math-zerop t3))
2130 0
2131 (if (or (math-evenp t2) (math-evenp t3))
2132 (if (or (math-negp t2) (math-negp t3))
2133 (if (math-posp high)
2134 0
2135 (list '/
2136 (list 'calcFunc-dfact
2137 (math-neg t2))
2138 (list 'calcFunc-dfact
2139 (math-sub -2 t3))))
2140 (list '/
2141 (list 'calcFunc-dfact t3)
2142 (list 'calcFunc-dfact
2143 (math-sub t2 2))))
2144 (if (math-negp t3)
2145 (list '*
2146 (list '^ -1
2147 (list '/ (list '- (list '- t2 t3)
2148 2)
2149 2))
2150 (list '/
2151 (list 'calcFunc-dfact
2152 (math-neg t2))
2153 (list 'calcFunc-dfact
2154 (math-sub -2 t3))))
2155 (if (math-posp t2)
2156 (list '/
2157 (list 'calcFunc-dfact t3)
2158 (list 'calcFunc-dfact
2159 (math-sub t2 2)))
2160 nil))))))))
2161 t2)))
2162 (if (equal val '(var nan var-nan)) (setq val nil))
2163 (or val
2164 (let* ((math-tabulate-initial 1)
2165 (math-tabulate-function 'calcFunc-prod))
2166 (calcFunc-table expr var low high)))))
2167
2168
2169
2170
2171 (defvar math-solve-ranges nil)
2172 ;;; Attempt to reduce lhs = rhs to solve-var = rhs', where solve-var appears
2173 ;;; in lhs but not in rhs or rhs'; return rhs'.
2174 ;;; Uses global values: solve-*.
2175 (defun math-try-solve-for (lhs rhs &optional sign no-poly)
2176 (let (t1 t2 t3)
2177 (cond ((equal lhs solve-var)
2178 (setq math-solve-sign sign)
2179 (if (eq solve-full 'all)
2180 (let ((vec (list 'vec (math-evaluate-expr rhs)))
2181 newvec var p)
2182 (while math-solve-ranges
2183 (setq p (car math-solve-ranges)
2184 var (car p)
2185 newvec (list 'vec))
2186 (while (setq p (cdr p))
2187 (setq newvec (nconc newvec
2188 (cdr (math-expr-subst
2189 vec var (car p))))))
2190 (setq vec newvec
2191 math-solve-ranges (cdr math-solve-ranges)))
2192 (math-normalize vec))
2193 rhs))
2194 ((Math-primp lhs)
2195 nil)
2196 ((and (eq (car lhs) '-)
2197 (eq (car-safe (nth 1 lhs)) (car-safe (nth 2 lhs)))
2198 (Math-zerop rhs)
2199 (= (length (nth 1 lhs)) 2)
2200 (= (length (nth 2 lhs)) 2)
2201 (setq t1 (get (car (nth 1 lhs)) 'math-inverse))
2202 (setq t2 (funcall t1 '(var SOLVEDUM SOLVEDUM)))
2203 (eq (math-expr-contains-count t2 '(var SOLVEDUM SOLVEDUM)) 1)
2204 (setq t3 (math-solve-above-dummy t2))
2205 (setq t1 (math-try-solve-for (math-sub (nth 1 (nth 1 lhs))
2206 (math-expr-subst
2207 t2 t3
2208 (nth 1 (nth 2 lhs))))
2209 0)))
2210 t1)
2211 ((eq (car lhs) 'neg)
2212 (math-try-solve-for (nth 1 lhs) (math-neg rhs)
2213 (and sign (- sign))))
2214 ((and (not (eq solve-full 't)) (math-try-solve-prod)))
2215 ((and (not no-poly)
2216 (setq t2 (math-decompose-poly lhs solve-var 15 rhs)))
2217 (setq t1 (cdr (nth 1 t2))
2218 t1 (let ((math-solve-ranges math-solve-ranges))
2219 (cond ((= (length t1) 5)
2220 (apply 'math-solve-quartic (car t2) t1))
2221 ((= (length t1) 4)
2222 (apply 'math-solve-cubic (car t2) t1))
2223 ((= (length t1) 3)
2224 (apply 'math-solve-quadratic (car t2) t1))
2225 ((= (length t1) 2)
2226 (apply 'math-solve-linear (car t2) sign t1))
2227 (solve-full
2228 (math-poly-all-roots (car t2) t1))
2229 (calc-symbolic-mode nil)
2230 (t
2231 (math-try-solve-for
2232 (car t2)
2233 (math-poly-any-root (reverse t1) 0 t)
2234 nil t)))))
2235 (if t1
2236 (if (eq (nth 2 t2) 1)
2237 t1
2238 (math-solve-prod t1 (math-try-solve-for (nth 2 t2) 0 nil t)))
2239 (calc-record-why "*Unable to find a symbolic solution")
2240 nil))
2241 ((and (math-solve-find-root-term lhs nil)
2242 (eq (math-expr-contains-count lhs t1) 1)) ; just in case
2243 (math-try-solve-for (math-simplify
2244 (math-sub (if (or t3 (math-evenp t2))
2245 (math-pow t1 t2)
2246 (math-neg (math-pow t1 t2)))
2247 (math-expand-power
2248 (math-sub (math-normalize
2249 (math-expr-subst
2250 lhs t1 0))
2251 rhs)
2252 t2 solve-var)))
2253 0))
2254 ((eq (car lhs) '+)
2255 (cond ((not (math-expr-contains (nth 1 lhs) solve-var))
2256 (math-try-solve-for (nth 2 lhs)
2257 (math-sub rhs (nth 1 lhs))
2258 sign))
2259 ((not (math-expr-contains (nth 2 lhs) solve-var))
2260 (math-try-solve-for (nth 1 lhs)
2261 (math-sub rhs (nth 2 lhs))
2262 sign))))
2263 ((eq (car lhs) 'calcFunc-eq)
2264 (math-try-solve-for (math-sub (nth 1 lhs) (nth 2 lhs))
2265 rhs sign no-poly))
2266 ((eq (car lhs) '-)
2267 (cond ((or (and (eq (car-safe (nth 1 lhs)) 'calcFunc-sin)
2268 (eq (car-safe (nth 2 lhs)) 'calcFunc-cos))
2269 (and (eq (car-safe (nth 1 lhs)) 'calcFunc-cos)
2270 (eq (car-safe (nth 2 lhs)) 'calcFunc-sin)))
2271 (math-try-solve-for (math-sub (nth 1 lhs)
2272 (list (car (nth 1 lhs))
2273 (math-sub
2274 (math-quarter-circle t)
2275 (nth 1 (nth 2 lhs)))))
2276 rhs))
2277 ((not (math-expr-contains (nth 1 lhs) solve-var))
2278 (math-try-solve-for (nth 2 lhs)
2279 (math-sub (nth 1 lhs) rhs)
2280 (and sign (- sign))))
2281 ((not (math-expr-contains (nth 2 lhs) solve-var))
2282 (math-try-solve-for (nth 1 lhs)
2283 (math-add rhs (nth 2 lhs))
2284 sign))))
2285 ((and (eq solve-full 't) (math-try-solve-prod)))
2286 ((and (eq (car lhs) '%)
2287 (not (math-expr-contains (nth 2 lhs) solve-var)))
2288 (math-try-solve-for (nth 1 lhs) (math-add rhs
2289 (math-solve-get-int
2290 (nth 2 lhs)))))
2291 ((eq (car lhs) 'calcFunc-log)
2292 (cond ((not (math-expr-contains (nth 2 lhs) solve-var))
2293 (math-try-solve-for (nth 1 lhs) (math-pow (nth 2 lhs) rhs)))
2294 ((not (math-expr-contains (nth 1 lhs) solve-var))
2295 (math-try-solve-for (nth 2 lhs) (math-pow
2296 (nth 1 lhs)
2297 (math-div 1 rhs))))))
2298 ((and (= (length lhs) 2)
2299 (symbolp (car lhs))
2300 (setq t1 (get (car lhs) 'math-inverse))
2301 (setq t2 (funcall t1 rhs)))
2302 (setq t1 (get (car lhs) 'math-inverse-sign))
2303 (math-try-solve-for (nth 1 lhs) (math-normalize t2)
2304 (and sign t1
2305 (if (integerp t1)
2306 (* t1 sign)
2307 (funcall t1 lhs sign)))))
2308 ((and (symbolp (car lhs))
2309 (setq t1 (get (car lhs) 'math-inverse-n))
2310 (setq t2 (funcall t1 lhs rhs)))
2311 t2)
2312 ((setq t1 (math-expand-formula lhs))
2313 (math-try-solve-for t1 rhs sign))
2314 (t
2315 (calc-record-why "*No inverse known" lhs)
2316 nil))))
2317
2318
2319 (defun math-try-solve-prod ()
2320 (cond ((eq (car lhs) '*)
2321 (cond ((not (math-expr-contains (nth 1 lhs) solve-var))
2322 (math-try-solve-for (nth 2 lhs)
2323 (math-div rhs (nth 1 lhs))
2324 (math-solve-sign sign (nth 1 lhs))))
2325 ((not (math-expr-contains (nth 2 lhs) solve-var))
2326 (math-try-solve-for (nth 1 lhs)
2327 (math-div rhs (nth 2 lhs))
2328 (math-solve-sign sign (nth 2 lhs))))
2329 ((Math-zerop rhs)
2330 (math-solve-prod (let ((math-solve-ranges math-solve-ranges))
2331 (math-try-solve-for (nth 2 lhs) 0))
2332 (math-try-solve-for (nth 1 lhs) 0)))))
2333 ((eq (car lhs) '/)
2334 (cond ((not (math-expr-contains (nth 1 lhs) solve-var))
2335 (math-try-solve-for (nth 2 lhs)
2336 (math-div (nth 1 lhs) rhs)
2337 (math-solve-sign sign (nth 1 lhs))))
2338 ((not (math-expr-contains (nth 2 lhs) solve-var))
2339 (math-try-solve-for (nth 1 lhs)
2340 (math-mul rhs (nth 2 lhs))
2341 (math-solve-sign sign (nth 2 lhs))))
2342 ((setq t1 (math-try-solve-for (math-sub (nth 1 lhs)
2343 (math-mul (nth 2 lhs)
2344 rhs))
2345 0))
2346 t1)))
2347 ((eq (car lhs) '^)
2348 (cond ((not (math-expr-contains (nth 1 lhs) solve-var))
2349 (math-try-solve-for
2350 (nth 2 lhs)
2351 (math-add (math-normalize
2352 (list 'calcFunc-log rhs (nth 1 lhs)))
2353 (math-div
2354 (math-mul 2
2355 (math-mul '(var pi var-pi)
2356 (math-solve-get-int
2357 '(var i var-i))))
2358 (math-normalize
2359 (list 'calcFunc-ln (nth 1 lhs)))))))
2360 ((not (math-expr-contains (nth 2 lhs) solve-var))
2361 (cond ((and (integerp (nth 2 lhs))
2362 (>= (nth 2 lhs) 2)
2363 (setq t1 (math-integer-log2 (nth 2 lhs))))
2364 (setq t2 rhs)
2365 (if (and (eq solve-full t)
2366 (math-known-realp (nth 1 lhs)))
2367 (progn
2368 (while (>= (setq t1 (1- t1)) 0)
2369 (setq t2 (list 'calcFunc-sqrt t2)))
2370 (setq t2 (math-solve-get-sign t2)))
2371 (while (>= (setq t1 (1- t1)) 0)
2372 (setq t2 (math-solve-get-sign
2373 (math-normalize
2374 (list 'calcFunc-sqrt t2))))))
2375 (math-try-solve-for
2376 (nth 1 lhs)
2377 (math-normalize t2)))
2378 ((math-looks-negp (nth 2 lhs))
2379 (math-try-solve-for
2380 (list '^ (nth 1 lhs) (math-neg (nth 2 lhs)))
2381 (math-div 1 rhs)))
2382 ((and (eq solve-full t)
2383 (Math-integerp (nth 2 lhs))
2384 (math-known-realp (nth 1 lhs)))
2385 (setq t1 (math-normalize
2386 (list 'calcFunc-nroot rhs (nth 2 lhs))))
2387 (if (math-evenp (nth 2 lhs))
2388 (setq t1 (math-solve-get-sign t1)))
2389 (math-try-solve-for
2390 (nth 1 lhs) t1
2391 (and sign
2392 (math-oddp (nth 2 lhs))
2393 (math-solve-sign sign (nth 2 lhs)))))
2394 (t (math-try-solve-for
2395 (nth 1 lhs)
2396 (math-mul
2397 (math-normalize
2398 (list 'calcFunc-exp
2399 (if (Math-realp (nth 2 lhs))
2400 (math-div (math-mul
2401 '(var pi var-pi)
2402 (math-solve-get-int
2403 '(var i var-i)
2404 (and (integerp (nth 2 lhs))
2405 (math-abs
2406 (nth 2 lhs)))))
2407 (math-div (nth 2 lhs) 2))
2408 (math-div (math-mul
2409 2
2410 (math-mul
2411 '(var pi var-pi)
2412 (math-solve-get-int
2413 '(var i var-i)
2414 (and (integerp (nth 2 lhs))
2415 (math-abs
2416 (nth 2 lhs))))))
2417 (nth 2 lhs)))))
2418 (math-normalize
2419 (list 'calcFunc-nroot
2420 rhs
2421 (nth 2 lhs))))
2422 (and sign
2423 (math-oddp (nth 2 lhs))
2424 (math-solve-sign sign (nth 2 lhs)))))))))
2425 (t nil)))
2426
2427 (defun math-solve-prod (lsoln rsoln)
2428 (cond ((null lsoln)
2429 rsoln)
2430 ((null rsoln)
2431 lsoln)
2432 ((eq solve-full 'all)
2433 (cons 'vec (append (cdr lsoln) (cdr rsoln))))
2434 (solve-full
2435 (list 'calcFunc-if
2436 (list 'calcFunc-gt (math-solve-get-sign 1) 0)
2437 lsoln
2438 rsoln))
2439 (t lsoln)))
2440
2441 ;;; This deals with negative, fractional, and symbolic powers of "x".
2442 (defun math-solve-poly-funny-powers (sub-rhs) ; uses "t1", "t2"
2443 (setq t1 lhs)
2444 (let ((pp math-poly-neg-powers)
2445 fac)
2446 (while pp
2447 (setq fac (math-pow (car pp) (or math-poly-mult-powers 1))
2448 t1 (math-mul t1 fac)
2449 rhs (math-mul rhs fac)
2450 pp (cdr pp))))
2451 (if sub-rhs (setq t1 (math-sub t1 rhs)))
2452 (let ((math-poly-neg-powers nil))
2453 (setq t2 (math-mul (or math-poly-mult-powers 1)
2454 (let ((calc-prefer-frac t))
2455 (math-div 1 math-poly-frac-powers)))
2456 t1 (math-is-polynomial (math-simplify (calcFunc-expand t1)) b 50))))
2457
2458 ;;; This converts "a x^8 + b x^5 + c x^2" to "(a (x^3)^2 + b (x^3) + c) * x^2".
2459 (defun math-solve-crunch-poly (max-degree) ; uses "t1", "t3"
2460 (let ((count 0))
2461 (while (and t1 (Math-zerop (car t1)))
2462 (setq t1 (cdr t1)
2463 count (1+ count)))
2464 (and t1
2465 (let* ((degree (1- (length t1)))
2466 (scale degree))
2467 (while (and (> scale 1) (= (car t3) 1))
2468 (and (= (% degree scale) 0)
2469 (let ((p t1)
2470 (n 0)
2471 (new-t1 nil)
2472 (okay t))
2473 (while (and p okay)
2474 (if (= (% n scale) 0)
2475 (setq new-t1 (nconc new-t1 (list (car p))))
2476 (or (Math-zerop (car p))
2477 (setq okay nil)))
2478 (setq p (cdr p)
2479 n (1+ n)))
2480 (if okay
2481 (setq t3 (cons scale (cdr t3))
2482 t1 new-t1))))
2483 (setq scale (1- scale)))
2484 (setq t3 (list (math-mul (car t3) t2) (math-mul count t2)))
2485 (<= (1- (length t1)) max-degree)))))
2486
2487 (defun calcFunc-poly (expr var &optional degree)
2488 (if degree
2489 (or (natnump degree) (math-reject-arg degree 'fixnatnump))
2490 (setq degree 50))
2491 (let ((p (math-is-polynomial expr var degree 'gen)))
2492 (if p
2493 (if (equal p '(0))
2494 (list 'vec)
2495 (cons 'vec p))
2496 (math-reject-arg expr "Expected a polynomial"))))
2497
2498 (defun calcFunc-gpoly (expr var &optional degree)
2499 (if degree
2500 (or (natnump degree) (math-reject-arg degree 'fixnatnump))
2501 (setq degree 50))
2502 (let* ((math-poly-base-variable var)
2503 (d (math-decompose-poly expr var degree nil)))
2504 (if d
2505 (cons 'vec d)
2506 (math-reject-arg expr "Expected a polynomial"))))
2507
2508 (defun math-decompose-poly (lhs solve-var degree sub-rhs)
2509 (let ((rhs (or sub-rhs 1))
2510 t1 t2 t3)
2511 (setq t2 (math-polynomial-base
2512 lhs
2513 (function
2514 (lambda (b)
2515 (let ((math-poly-neg-powers '(1))
2516 (math-poly-mult-powers nil)
2517 (math-poly-frac-powers 1)
2518 (math-poly-exp-base t))
2519 (and (not (equal b lhs))
2520 (or (not (memq (car-safe b) '(+ -))) sub-rhs)
2521 (setq t3 '(1 0) t2 1
2522 t1 (math-is-polynomial lhs b 50))
2523 (if (and (equal math-poly-neg-powers '(1))
2524 (memq math-poly-mult-powers '(nil 1))
2525 (eq math-poly-frac-powers 1)
2526 sub-rhs)
2527 (setq t1 (cons (math-sub (car t1) rhs)
2528 (cdr t1)))
2529 (math-solve-poly-funny-powers sub-rhs))
2530 (math-solve-crunch-poly degree)
2531 (or (math-expr-contains b solve-var)
2532 (math-expr-contains (car t3) solve-var))))))))
2533 (if t2
2534 (list (math-pow t2 (car t3))
2535 (cons 'vec t1)
2536 (if sub-rhs
2537 (math-pow t2 (nth 1 t3))
2538 (math-div (math-pow t2 (nth 1 t3)) rhs))))))
2539
2540 (defun math-solve-linear (var sign b a)
2541 (math-try-solve-for var
2542 (math-div (math-neg b) a)
2543 (math-solve-sign sign a)
2544 t))
2545
2546 (defun math-solve-quadratic (var c b a)
2547 (math-try-solve-for
2548 var
2549 (if (math-looks-evenp b)
2550 (let ((halfb (math-div b 2)))
2551 (math-div
2552 (math-add
2553 (math-neg halfb)
2554 (math-solve-get-sign
2555 (math-normalize
2556 (list 'calcFunc-sqrt
2557 (math-add (math-sqr halfb)
2558 (math-mul (math-neg c) a))))))
2559 a))
2560 (math-div
2561 (math-add
2562 (math-neg b)
2563 (math-solve-get-sign
2564 (math-normalize
2565 (list 'calcFunc-sqrt
2566 (math-add (math-sqr b)
2567 (math-mul 4 (math-mul (math-neg c) a)))))))
2568 (math-mul 2 a)))
2569 nil t))
2570
2571 (defun math-solve-cubic (var d c b a)
2572 (let* ((p (math-div b a))
2573 (q (math-div c a))
2574 (r (math-div d a))
2575 (psqr (math-sqr p))
2576 (aa (math-sub q (math-div psqr 3)))
2577 (bb (math-add r
2578 (math-div (math-sub (math-mul 2 (math-mul psqr p))
2579 (math-mul 9 (math-mul p q)))
2580 27)))
2581 m)
2582 (if (Math-zerop aa)
2583 (math-try-solve-for (math-pow (math-add var (math-div p 3)) 3)
2584 (math-neg bb) nil t)
2585 (if (Math-zerop bb)
2586 (math-try-solve-for
2587 (math-mul (math-add var (math-div p 3))
2588 (math-add (math-sqr (math-add var (math-div p 3)))
2589 aa))
2590 0 nil t)
2591 (setq m (math-mul 2 (list 'calcFunc-sqrt (math-div aa -3))))
2592 (math-try-solve-for
2593 var
2594 (math-sub
2595 (math-normalize
2596 (math-mul
2597 m
2598 (list 'calcFunc-cos
2599 (math-div
2600 (math-sub (list 'calcFunc-arccos
2601 (math-div (math-mul 3 bb)
2602 (math-mul aa m)))
2603 (math-mul 2
2604 (math-mul
2605 (math-add 1 (math-solve-get-int
2606 1 3))
2607 (math-half-circle
2608 calc-symbolic-mode))))
2609 3))))
2610 (math-div p 3))
2611 nil t)))))
2612
2613 (defun math-solve-quartic (var d c b a aa)
2614 (setq a (math-div a aa))
2615 (setq b (math-div b aa))
2616 (setq c (math-div c aa))
2617 (setq d (math-div d aa))
2618 (math-try-solve-for
2619 var
2620 (let* ((asqr (math-sqr a))
2621 (asqr4 (math-div asqr 4))
2622 (y (let ((solve-full nil)
2623 calc-next-why)
2624 (math-solve-cubic solve-var
2625 (math-sub (math-sub
2626 (math-mul 4 (math-mul b d))
2627 (math-mul asqr d))
2628 (math-sqr c))
2629 (math-sub (math-mul a c)
2630 (math-mul 4 d))
2631 (math-neg b)
2632 1)))
2633 (rsqr (math-add (math-sub asqr4 b) y))
2634 (r (list 'calcFunc-sqrt rsqr))
2635 (sign1 (math-solve-get-sign 1))
2636 (de (list 'calcFunc-sqrt
2637 (math-add
2638 (math-sub (math-mul 3 asqr4)
2639 (math-mul 2 b))
2640 (if (Math-zerop rsqr)
2641 (math-mul
2642 2
2643 (math-mul sign1
2644 (list 'calcFunc-sqrt
2645 (math-sub (math-sqr y)
2646 (math-mul 4 d)))))
2647 (math-sub
2648 (math-mul sign1
2649 (math-div
2650 (math-sub (math-sub
2651 (math-mul 4 (math-mul a b))
2652 (math-mul 8 c))
2653 (math-mul asqr a))
2654 (math-mul 4 r)))
2655 rsqr))))))
2656 (math-normalize
2657 (math-sub (math-add (math-mul sign1 (math-div r 2))
2658 (math-solve-get-sign (math-div de 2)))
2659 (math-div a 4))))
2660 nil t))
2661
2662 (defvar math-symbolic-solve nil)
2663 (defvar math-int-coefs nil)
2664 (defun math-poly-all-roots (var p &optional math-factoring)
2665 (catch 'ouch
2666 (let* ((math-symbolic-solve calc-symbolic-mode)
2667 (roots nil)
2668 (deg (1- (length p)))
2669 (orig-p (reverse p))
2670 (math-int-coefs nil)
2671 (math-int-scale nil)
2672 (math-double-roots nil)
2673 (math-int-factors nil)
2674 (math-int-threshold nil)
2675 (pp p))
2676 ;; If rational coefficients, look for exact rational factors.
2677 (while (and pp (Math-ratp (car pp)))
2678 (setq pp (cdr pp)))
2679 (if pp
2680 (if (or math-factoring math-symbolic-solve)
2681 (throw 'ouch nil))
2682 (let ((lead (car orig-p))
2683 (calc-prefer-frac t)
2684 (scale (apply 'math-lcm-denoms p)))
2685 (setq math-int-scale (math-abs (math-mul scale lead))
2686 math-int-threshold (math-div '(float 5 -2) math-int-scale)
2687 math-int-coefs (cdr (math-div (cons 'vec orig-p) lead)))))
2688 (if (> deg 4)
2689 (let ((calc-prefer-frac nil)
2690 (calc-symbolic-mode nil)
2691 (pp p)
2692 (def-p (copy-sequence orig-p)))
2693 (while pp
2694 (if (Math-numberp (car pp))
2695 (setq pp (cdr pp))
2696 (throw 'ouch nil)))
2697 (while (> deg (if math-symbolic-solve 2 4))
2698 (let* ((x (math-poly-any-root def-p '(float 0 0) nil))
2699 b c pp)
2700 (if (and (eq (car-safe x) 'cplx)
2701 (math-nearly-zerop (nth 2 x) (nth 1 x)))
2702 (setq x (calcFunc-re x)))
2703 (or math-factoring
2704 (setq roots (cons x roots)))
2705 (or (math-numberp x)
2706 (setq x (math-evaluate-expr x)))
2707 (setq pp def-p
2708 b (car def-p))
2709 (while (setq pp (cdr pp))
2710 (setq c (car pp))
2711 (setcar pp b)
2712 (setq b (math-add (math-mul x b) c)))
2713 (setq def-p (cdr def-p)
2714 deg (1- deg))))
2715 (setq p (reverse def-p))))
2716 (if (> deg 1)
2717 (let ((solve-var '(var DUMMY var-DUMMY))
2718 (math-solve-sign nil)
2719 (math-solve-ranges nil)
2720 (solve-full 'all))
2721 (if (= (length p) (length math-int-coefs))
2722 (setq p (reverse math-int-coefs)))
2723 (setq roots (append (cdr (apply (cond ((= deg 2)
2724 'math-solve-quadratic)
2725 ((= deg 3)
2726 'math-solve-cubic)
2727 (t
2728 'math-solve-quartic))
2729 solve-var p))
2730 roots)))
2731 (if (> deg 0)
2732 (setq roots (cons (math-div (math-neg (car p)) (nth 1 p))
2733 roots))))
2734 (if math-factoring
2735 (progn
2736 (while roots
2737 (math-poly-integer-root (car roots))
2738 (setq roots (cdr roots)))
2739 (list math-int-factors (nreverse math-int-coefs) math-int-scale))
2740 (let ((vec nil) res)
2741 (while roots
2742 (let ((root (car roots))
2743 (solve-full (and solve-full 'all)))
2744 (if (math-floatp root)
2745 (setq root (math-poly-any-root orig-p root t)))
2746 (setq vec (append vec
2747 (cdr (or (math-try-solve-for var root nil t)
2748 (throw 'ouch nil))))))
2749 (setq roots (cdr roots)))
2750 (setq vec (cons 'vec (nreverse vec)))
2751 (if math-symbolic-solve
2752 (setq vec (math-normalize vec)))
2753 (if (eq solve-full t)
2754 (list 'calcFunc-subscr
2755 vec
2756 (math-solve-get-int 1 (1- (length orig-p)) 1))
2757 vec))))))
2758
2759 (defun math-lcm-denoms (&rest fracs)
2760 (let ((den 1))
2761 (while fracs
2762 (if (eq (car-safe (car fracs)) 'frac)
2763 (setq den (calcFunc-lcm den (nth 2 (car fracs)))))
2764 (setq fracs (cdr fracs)))
2765 den))
2766
2767 (defun math-poly-any-root (p x polish) ; p is a reverse poly coeff list
2768 (let* ((newt (if (math-zerop x)
2769 (math-poly-newton-root
2770 p '(cplx (float 123 -6) (float 1 -4)) 4)
2771 (math-poly-newton-root p x 4)))
2772 (res (if (math-zerop (cdr newt))
2773 (car newt)
2774 (if (and (math-lessp (cdr newt) '(float 1 -3)) (not polish))
2775 (setq newt (math-poly-newton-root p (car newt) 30)))
2776 (if (math-zerop (cdr newt))
2777 (car newt)
2778 (math-poly-laguerre-root p x polish)))))
2779 (and math-symbolic-solve (math-floatp res)
2780 (throw 'ouch nil))
2781 res))
2782
2783 (defun math-poly-newton-root (p x iters)
2784 (let* ((calc-prefer-frac nil)
2785 (calc-symbolic-mode nil)
2786 (try-integer math-int-coefs)
2787 (dx x) b d)
2788 (while (and (> (setq iters (1- iters)) 0)
2789 (let ((pp p))
2790 (math-working "newton" x)
2791 (setq b (car p)
2792 d 0)
2793 (while (setq pp (cdr pp))
2794 (setq d (math-add (math-mul x d) b)
2795 b (math-add (math-mul x b) (car pp))))
2796 (not (math-zerop d)))
2797 (progn
2798 (setq dx (math-div b d)
2799 x (math-sub x dx))
2800 (if try-integer
2801 (let ((adx (math-abs-approx dx)))
2802 (and (math-lessp adx math-int-threshold)
2803 (let ((iroot (math-poly-integer-root x)))
2804 (if iroot
2805 (setq x iroot dx 0)
2806 (setq try-integer nil))))))
2807 (or (not (or (eq dx 0)
2808 (math-nearly-zerop dx (math-abs-approx x))))
2809 (progn (setq dx 0) nil)))))
2810 (cons x (if (math-zerop x)
2811 1 (math-div (math-abs-approx dx) (math-abs-approx x))))))
2812
2813 (defun math-poly-integer-root (x)
2814 (and (math-lessp (calcFunc-xpon (math-abs-approx x)) calc-internal-prec)
2815 math-int-coefs
2816 (let* ((calc-prefer-frac t)
2817 (xre (calcFunc-re x))
2818 (xim (calcFunc-im x))
2819 (xresq (math-sqr xre))
2820 (ximsq (math-sqr xim)))
2821 (if (math-lessp ximsq (calcFunc-scf xresq -1))
2822 ;; Look for linear factor
2823 (let* ((rnd (math-div (math-round (math-mul xre math-int-scale))
2824 math-int-scale))
2825 (icp math-int-coefs)
2826 (rem (car icp))
2827 (newcoef nil))
2828 (while (setq icp (cdr icp))
2829 (setq newcoef (cons rem newcoef)
2830 rem (math-add (car icp)
2831 (math-mul rem rnd))))
2832 (and (math-zerop rem)
2833 (progn
2834 (setq math-int-coefs (nreverse newcoef)
2835 math-int-factors (cons (list (math-neg rnd))
2836 math-int-factors))
2837 rnd)))
2838 ;; Look for irreducible quadratic factor
2839 (let* ((rnd1 (math-div (math-round
2840 (math-mul xre (math-mul -2 math-int-scale)))
2841 math-int-scale))
2842 (sqscale (math-sqr math-int-scale))
2843 (rnd0 (math-div (math-round (math-mul (math-add xresq ximsq)
2844 sqscale))
2845 sqscale))
2846 (rem1 (car math-int-coefs))
2847 (icp (cdr math-int-coefs))
2848 (rem0 (car icp))
2849 (newcoef nil)
2850 (found (assoc (list rnd0 rnd1 (math-posp xim))
2851 math-double-roots))
2852 this)
2853 (if found
2854 (setq math-double-roots (delq found math-double-roots)
2855 rem0 0 rem1 0)
2856 (while (setq icp (cdr icp))
2857 (setq this rem1
2858 newcoef (cons rem1 newcoef)
2859 rem1 (math-sub rem0 (math-mul this rnd1))
2860 rem0 (math-sub (car icp) (math-mul this rnd0)))))
2861 (and (math-zerop rem0)
2862 (math-zerop rem1)
2863 (let ((aa (math-div rnd1 -2)))
2864 (or found (setq math-int-coefs (reverse newcoef)
2865 math-double-roots (cons (list
2866 (list
2867 rnd0 rnd1
2868 (math-negp xim)))
2869 math-double-roots)
2870 math-int-factors (cons (cons rnd0 rnd1)
2871 math-int-factors)))
2872 (math-add aa
2873 (let ((calc-symbolic-mode math-symbolic-solve))
2874 (math-mul (math-sqrt (math-sub (math-sqr aa)
2875 rnd0))
2876 (if (math-negp xim) -1 1)))))))))))
2877
2878 ;;; The following routine is from Numerical Recipes, section 9.5.
2879 (defun math-poly-laguerre-root (p x polish)
2880 (let* ((calc-prefer-frac nil)
2881 (calc-symbolic-mode nil)
2882 (iters 0)
2883 (m (1- (length p)))
2884 (try-newt (not polish))
2885 (tried-newt nil)
2886 b d f x1 dx dxold)
2887 (while
2888 (and (or (< (setq iters (1+ iters)) 50)
2889 (math-reject-arg x "*Laguerre's method failed to converge"))
2890 (let ((err (math-abs-approx (car p)))
2891 (abx (math-abs-approx x))
2892 (pp p))
2893 (setq b (car p)
2894 d 0 f 0)
2895 (while (setq pp (cdr pp))
2896 (setq f (math-add (math-mul x f) d)
2897 d (math-add (math-mul x d) b)
2898 b (math-add (math-mul x b) (car pp))
2899 err (math-add (math-abs-approx b) (math-mul abx err))))
2900 (math-lessp (calcFunc-scf err (- -2 calc-internal-prec))
2901 (math-abs-approx b)))
2902 (or (not (math-zerop d))
2903 (not (math-zerop f))
2904 (progn
2905 (setq x (math-pow (math-neg b) (list 'frac 1 m)))
2906 nil))
2907 (let* ((g (math-div d b))
2908 (g2 (math-sqr g))
2909 (h (math-sub g2 (math-mul 2 (math-div f b))))
2910 (sq (math-sqrt
2911 (math-mul (1- m) (math-sub (math-mul m h) g2))))
2912 (gp (math-add g sq))
2913 (gm (math-sub g sq)))
2914 (if (math-lessp (calcFunc-abssqr gp) (calcFunc-abssqr gm))
2915 (setq gp gm))
2916 (setq dx (math-div m gp)
2917 x1 (math-sub x dx))
2918 (if (and try-newt
2919 (math-lessp (math-abs-approx dx)
2920 (calcFunc-scf (math-abs-approx x) -3)))
2921 (let ((newt (math-poly-newton-root p x1 7)))
2922 (setq tried-newt t
2923 try-newt nil)
2924 (if (math-zerop (cdr newt))
2925 (setq x (car newt) x1 x)
2926 (if (math-lessp (cdr newt) '(float 1 -6))
2927 (let ((newt2 (math-poly-newton-root
2928 p (car newt) 20)))
2929 (if (math-zerop (cdr newt2))
2930 (setq x (car newt2) x1 x)
2931 (setq x (car newt))))))))
2932 (not (or (eq x x1)
2933 (math-nearly-equal x x1))))
2934 (let ((cdx (math-abs-approx dx)))
2935 (setq x x1
2936 tried-newt nil)
2937 (prog1
2938 (or (<= iters 6)
2939 (math-lessp cdx dxold)
2940 (progn
2941 (if polish
2942 (let ((digs (calcFunc-xpon
2943 (math-div (math-abs-approx x) cdx))))
2944 (calc-record-why
2945 "*Could not attain full precision")
2946 (if (natnump digs)
2947 (let ((calc-internal-prec (max 3 digs)))
2948 (setq x (math-normalize x))))))
2949 nil))
2950 (setq dxold cdx)))
2951 (or polish
2952 (math-lessp (calcFunc-scf (math-abs-approx x)
2953 (- calc-internal-prec))
2954 dxold))))
2955 (or (and (math-floatp x)
2956 (math-poly-integer-root x))
2957 x)))
2958
2959 (defun math-solve-above-dummy (x)
2960 (and (not (Math-primp x))
2961 (if (and (equal (nth 1 x) '(var SOLVEDUM SOLVEDUM))
2962 (= (length x) 2))
2963 x
2964 (let ((res nil))
2965 (while (and (setq x (cdr x))
2966 (not (setq res (math-solve-above-dummy (car x))))))
2967 res))))
2968
2969 (defun math-solve-find-root-term (x neg) ; sets "t2", "t3"
2970 (if (math-solve-find-root-in-prod x)
2971 (setq t3 neg
2972 t1 x)
2973 (and (memq (car-safe x) '(+ -))
2974 (or (math-solve-find-root-term (nth 1 x) neg)
2975 (math-solve-find-root-term (nth 2 x)
2976 (if (eq (car x) '-) (not neg) neg))))))
2977
2978 (defun math-solve-find-root-in-prod (x)
2979 (and (consp x)
2980 (math-expr-contains x solve-var)
2981 (or (and (eq (car x) 'calcFunc-sqrt)
2982 (setq t2 2))
2983 (and (eq (car x) '^)
2984 (or (and (memq (math-quarter-integer (nth 2 x)) '(1 2 3))
2985 (setq t2 2))
2986 (and (eq (car-safe (nth 2 x)) 'frac)
2987 (eq (nth 2 (nth 2 x)) 3)
2988 (setq t2 3))))
2989 (and (memq (car x) '(* /))
2990 (or (and (not (math-expr-contains (nth 1 x) solve-var))
2991 (math-solve-find-root-in-prod (nth 2 x)))
2992 (and (not (math-expr-contains (nth 2 x) solve-var))
2993 (math-solve-find-root-in-prod (nth 1 x))))))))
2994
2995
2996 (defun math-solve-system (exprs solve-vars solve-full)
2997 (setq exprs (mapcar 'list (if (Math-vectorp exprs)
2998 (cdr exprs)
2999 (list exprs)))
3000 solve-vars (if (Math-vectorp solve-vars)
3001 (cdr solve-vars)
3002 (list solve-vars)))
3003 (or (let ((math-solve-simplifying nil))
3004 (math-solve-system-rec exprs solve-vars nil))
3005 (let ((math-solve-simplifying t))
3006 (math-solve-system-rec exprs solve-vars nil))))
3007
3008 ;;; The following backtracking solver works by choosing a variable
3009 ;;; and equation, and trying to solve the equation for the variable.
3010 ;;; If it succeeds it calls itself recursively with that variable and
3011 ;;; equation removed from their respective lists, and with the solution
3012 ;;; added to solns as well as being substituted into all existing
3013 ;;; equations. The algorithm terminates when any solution path
3014 ;;; manages to remove all the variables from var-list.
3015
3016 ;;; To support calcFunc-roots, entries in eqn-list and solns are
3017 ;;; actually lists of equations.
3018
3019 (defun math-solve-system-rec (eqn-list var-list solns)
3020 (if var-list
3021 (let ((v var-list)
3022 (res nil))
3023
3024 ;; Try each variable in turn.
3025 (while
3026 (and
3027 v
3028 (let* ((vv (car v))
3029 (e eqn-list)
3030 (elim (eq (car-safe vv) 'calcFunc-elim)))
3031 (if elim
3032 (setq vv (nth 1 vv)))
3033
3034 ;; Try each equation in turn.
3035 (while
3036 (and
3037 e
3038 (let ((e2 (car e))
3039 (eprev nil)
3040 res2)
3041 (setq res nil)
3042
3043 ;; Try to solve for vv the list of equations e2.
3044 (while (and e2
3045 (setq res2 (or (and (eq (car e2) eprev)
3046 res2)
3047 (math-solve-for (car e2) 0 vv
3048 solve-full))))
3049 (setq eprev (car e2)
3050 res (cons (if (eq solve-full 'all)
3051 (cdr res2)
3052 (list res2))
3053 res)
3054 e2 (cdr e2)))
3055 (if e2
3056 (setq res nil)
3057
3058 ;; Found a solution. Now try other variables.
3059 (setq res (nreverse res)
3060 res (math-solve-system-rec
3061 (mapcar
3062 'math-solve-system-subst
3063 (delq (car e)
3064 (copy-sequence eqn-list)))
3065 (delq (car v) (copy-sequence var-list))
3066 (let ((math-solve-simplifying nil)
3067 (s (mapcar
3068 (function
3069 (lambda (x)
3070 (cons
3071 (car x)
3072 (math-solve-system-subst
3073 (cdr x)))))
3074 solns)))
3075 (if elim
3076 s
3077 (cons (cons vv (apply 'append res))
3078 s)))))
3079 (not res))))
3080 (setq e (cdr e)))
3081 (not res)))
3082 (setq v (cdr v)))
3083 res)
3084
3085 ;; Eliminated all variables, so now put solution into the proper format.
3086 (setq solns (sort solns
3087 (function
3088 (lambda (x y)
3089 (not (memq (car x) (memq (car y) solve-vars)))))))
3090 (if (eq solve-full 'all)
3091 (math-transpose
3092 (math-normalize
3093 (cons 'vec
3094 (if solns
3095 (mapcar (function (lambda (x) (cons 'vec (cdr x)))) solns)
3096 (mapcar (function (lambda (x) (cons 'vec x))) eqn-list)))))
3097 (math-normalize
3098 (cons 'vec
3099 (if solns
3100 (mapcar (function (lambda (x) (cons 'calcFunc-eq x))) solns)
3101 (mapcar 'car eqn-list)))))))
3102
3103 (defun math-solve-system-subst (x) ; uses "res" and "v"
3104 (let ((accum nil)
3105 (res2 res))
3106 (while x
3107 (setq accum (nconc accum
3108 (mapcar (function
3109 (lambda (r)
3110 (if math-solve-simplifying
3111 (math-simplify
3112 (math-expr-subst (car x) vv r))
3113 (math-expr-subst (car x) vv r))))
3114 (car res2)))
3115 x (cdr x)
3116 res2 (cdr res2)))
3117 accum))
3118
3119
3120 (defun math-get-from-counter (name)
3121 (let ((ctr (assq name calc-command-flags)))
3122 (if ctr
3123 (setcdr ctr (1+ (cdr ctr)))
3124 (setq ctr (cons name 1)
3125 calc-command-flags (cons ctr calc-command-flags)))
3126 (cdr ctr)))
3127
3128 (defun math-solve-get-sign (val)
3129 (setq val (math-simplify val))
3130 (if (and (eq (car-safe val) '*)
3131 (Math-numberp (nth 1 val)))
3132 (list '* (nth 1 val) (math-solve-get-sign (nth 2 val)))
3133 (and (eq (car-safe val) 'calcFunc-sqrt)
3134 (eq (car-safe (nth 1 val)) '^)
3135 (setq val (math-normalize (list '^
3136 (nth 1 (nth 1 val))
3137 (math-div (nth 2 (nth 1 val)) 2)))))
3138 (if solve-full
3139 (if (and (calc-var-value 'var-GenCount)
3140 (Math-natnump var-GenCount)
3141 (not (eq solve-full 'all)))
3142 (prog1
3143 (math-mul (list 'calcFunc-as var-GenCount) val)
3144 (setq var-GenCount (math-add var-GenCount 1))
3145 (calc-refresh-evaltos 'var-GenCount))
3146 (let* ((var (concat "s" (int-to-string (math-get-from-counter 'solve-sign))))
3147 (var2 (list 'var (intern var) (intern (concat "var-" var)))))
3148 (if (eq solve-full 'all)
3149 (setq math-solve-ranges (cons (list var2 1 -1)
3150 math-solve-ranges)))
3151 (math-mul var2 val)))
3152 (calc-record-why "*Choosing positive solution")
3153 val)))
3154
3155 (defun math-solve-get-int (val &optional range first)
3156 (if solve-full
3157 (if (and (calc-var-value 'var-GenCount)
3158 (Math-natnump var-GenCount)
3159 (not (eq solve-full 'all)))
3160 (prog1
3161 (math-mul val (list 'calcFunc-an var-GenCount))
3162 (setq var-GenCount (math-add var-GenCount 1))
3163 (calc-refresh-evaltos 'var-GenCount))
3164 (let* ((var (concat "n" (int-to-string
3165 (math-get-from-counter 'solve-int))))
3166 (var2 (list 'var (intern var) (intern (concat "var-" var)))))
3167 (if (and range (eq solve-full 'all))
3168 (setq math-solve-ranges (cons (cons var2
3169 (cdr (calcFunc-index
3170 range (or first 0))))
3171 math-solve-ranges)))
3172 (math-mul val var2)))
3173 (calc-record-why "*Choosing 0 for arbitrary integer in solution")
3174 0))
3175
3176 (defun math-solve-sign (sign expr)
3177 (and sign
3178 (let ((s1 (math-possible-signs expr)))
3179 (cond ((memq s1 '(4 6))
3180 sign)
3181 ((memq s1 '(1 3))
3182 (- sign))))))
3183
3184 (defun math-looks-evenp (expr)
3185 (if (Math-integerp expr)
3186 (math-evenp expr)
3187 (if (memq (car expr) '(* /))
3188 (math-looks-evenp (nth 1 expr)))))
3189
3190 (defun math-solve-for (lhs rhs solve-var solve-full &optional sign)
3191 (if (math-expr-contains rhs solve-var)
3192 (math-solve-for (math-sub lhs rhs) 0 solve-var solve-full)
3193 (and (math-expr-contains lhs solve-var)
3194 (math-with-extra-prec 1
3195 (let* ((math-poly-base-variable solve-var)
3196 (res (math-try-solve-for lhs rhs sign)))
3197 (if (and (eq solve-full 'all)
3198 (math-known-realp solve-var))
3199 (let ((old-len (length res))
3200 new-len)
3201 (setq res (delq nil
3202 (mapcar (function
3203 (lambda (x)
3204 (and (not (memq (car-safe x)
3205 '(cplx polar)))
3206 x)))
3207 res))
3208 new-len (length res))
3209 (if (< new-len old-len)
3210 (calc-record-why (if (= new-len 1)
3211 "*All solutions were complex"
3212 (format
3213 "*Omitted %d complex solutions"
3214 (- old-len new-len)))))))
3215 res)))))
3216
3217 (defun math-solve-eqn (expr var full)
3218 (if (memq (car-safe expr) '(calcFunc-neq calcFunc-lt calcFunc-gt
3219 calcFunc-leq calcFunc-geq))
3220 (let ((res (math-solve-for (cons '- (cdr expr))
3221 0 var full
3222 (if (eq (car expr) 'calcFunc-neq) nil 1))))
3223 (and res
3224 (if (eq math-solve-sign 1)
3225 (list (car expr) var res)
3226 (if (eq math-solve-sign -1)
3227 (list (car expr) res var)
3228 (or (eq (car expr) 'calcFunc-neq)
3229 (calc-record-why
3230 "*Can't determine direction of inequality"))
3231 (and (memq (car expr) '(calcFunc-neq calcFunc-lt calcFunc-gt))
3232 (list 'calcFunc-neq var res))))))
3233 (let ((res (math-solve-for expr 0 var full)))
3234 (and res
3235 (list 'calcFunc-eq var res)))))
3236
3237 (defun math-reject-solution (expr var func)
3238 (if (math-expr-contains expr var)
3239 (or (equal (car calc-next-why) '(* "Unable to find a symbolic solution"))
3240 (calc-record-why "*Unable to find a solution")))
3241 (list func expr var))
3242
3243 (defun calcFunc-solve (expr var)
3244 (or (if (or (Math-vectorp expr) (Math-vectorp var))
3245 (math-solve-system expr var nil)
3246 (math-solve-eqn expr var nil))
3247 (math-reject-solution expr var 'calcFunc-solve)))
3248
3249 (defun calcFunc-fsolve (expr var)
3250 (or (if (or (Math-vectorp expr) (Math-vectorp var))
3251 (math-solve-system expr var t)
3252 (math-solve-eqn expr var t))
3253 (math-reject-solution expr var 'calcFunc-fsolve)))
3254
3255 (defun calcFunc-roots (expr var)
3256 (let ((math-solve-ranges nil))
3257 (or (if (or (Math-vectorp expr) (Math-vectorp var))
3258 (math-solve-system expr var 'all)
3259 (math-solve-for expr 0 var 'all))
3260 (math-reject-solution expr var 'calcFunc-roots))))
3261
3262 (defun calcFunc-finv (expr var)
3263 (let ((res (math-solve-for expr math-integ-var var nil)))
3264 (if res
3265 (math-normalize (math-expr-subst res math-integ-var var))
3266 (math-reject-solution expr var 'calcFunc-finv))))
3267
3268 (defun calcFunc-ffinv (expr var)
3269 (let ((res (math-solve-for expr math-integ-var var t)))
3270 (if res
3271 (math-normalize (math-expr-subst res math-integ-var var))
3272 (math-reject-solution expr var 'calcFunc-finv))))
3273
3274
3275 (put 'calcFunc-inv 'math-inverse
3276 (function (lambda (x) (math-div 1 x))))
3277 (put 'calcFunc-inv 'math-inverse-sign -1)
3278
3279 (put 'calcFunc-sqrt 'math-inverse
3280 (function (lambda (x) (math-sqr x))))
3281
3282 (put 'calcFunc-conj 'math-inverse
3283 (function (lambda (x) (list 'calcFunc-conj x))))
3284
3285 (put 'calcFunc-abs 'math-inverse
3286 (function (lambda (x) (math-solve-get-sign x))))
3287
3288 (put 'calcFunc-deg 'math-inverse
3289 (function (lambda (x) (list 'calcFunc-rad x))))
3290 (put 'calcFunc-deg 'math-inverse-sign 1)
3291
3292 (put 'calcFunc-rad 'math-inverse
3293 (function (lambda (x) (list 'calcFunc-deg x))))
3294 (put 'calcFunc-rad 'math-inverse-sign 1)
3295
3296 (put 'calcFunc-ln 'math-inverse
3297 (function (lambda (x) (list 'calcFunc-exp x))))
3298 (put 'calcFunc-ln 'math-inverse-sign 1)
3299
3300 (put 'calcFunc-log10 'math-inverse
3301 (function (lambda (x) (list 'calcFunc-exp10 x))))
3302 (put 'calcFunc-log10 'math-inverse-sign 1)
3303
3304 (put 'calcFunc-lnp1 'math-inverse
3305 (function (lambda (x) (list 'calcFunc-expm1 x))))
3306 (put 'calcFunc-lnp1 'math-inverse-sign 1)
3307
3308 (put 'calcFunc-exp 'math-inverse
3309 (function (lambda (x) (math-add (math-normalize (list 'calcFunc-ln x))
3310 (math-mul 2
3311 (math-mul '(var pi var-pi)
3312 (math-solve-get-int
3313 '(var i var-i))))))))
3314 (put 'calcFunc-exp 'math-inverse-sign 1)
3315
3316 (put 'calcFunc-expm1 'math-inverse
3317 (function (lambda (x) (math-add (math-normalize (list 'calcFunc-lnp1 x))
3318 (math-mul 2
3319 (math-mul '(var pi var-pi)
3320 (math-solve-get-int
3321 '(var i var-i))))))))
3322 (put 'calcFunc-expm1 'math-inverse-sign 1)
3323
3324 (put 'calcFunc-sin 'math-inverse
3325 (function (lambda (x) (let ((n (math-solve-get-int 1)))
3326 (math-add (math-mul (math-normalize
3327 (list 'calcFunc-arcsin x))
3328 (math-pow -1 n))
3329 (math-mul (math-half-circle t)
3330 n))))))
3331
3332 (put 'calcFunc-cos 'math-inverse
3333 (function (lambda (x) (math-add (math-solve-get-sign
3334 (math-normalize
3335 (list 'calcFunc-arccos x)))
3336 (math-solve-get-int
3337 (math-full-circle t))))))
3338
3339 (put 'calcFunc-tan 'math-inverse
3340 (function (lambda (x) (math-add (math-normalize (list 'calcFunc-arctan x))
3341 (math-solve-get-int
3342 (math-half-circle t))))))
3343
3344 (put 'calcFunc-arcsin 'math-inverse
3345 (function (lambda (x) (math-normalize (list 'calcFunc-sin x)))))
3346
3347 (put 'calcFunc-arccos 'math-inverse
3348 (function (lambda (x) (math-normalize (list 'calcFunc-cos x)))))
3349
3350 (put 'calcFunc-arctan 'math-inverse
3351 (function (lambda (x) (math-normalize (list 'calcFunc-tan x)))))
3352
3353 (put 'calcFunc-sinh 'math-inverse
3354 (function (lambda (x) (let ((n (math-solve-get-int 1)))
3355 (math-add (math-mul (math-normalize
3356 (list 'calcFunc-arcsinh x))
3357 (math-pow -1 n))
3358 (math-mul (math-half-circle t)
3359 (math-mul
3360 '(var i var-i)
3361 n)))))))
3362 (put 'calcFunc-sinh 'math-inverse-sign 1)
3363
3364 (put 'calcFunc-cosh 'math-inverse
3365 (function (lambda (x) (math-add (math-solve-get-sign
3366 (math-normalize
3367 (list 'calcFunc-arccosh x)))
3368 (math-mul (math-full-circle t)
3369 (math-solve-get-int
3370 '(var i var-i)))))))
3371
3372 (put 'calcFunc-tanh 'math-inverse
3373 (function (lambda (x) (math-add (math-normalize
3374 (list 'calcFunc-arctanh x))
3375 (math-mul (math-half-circle t)
3376 (math-solve-get-int
3377 '(var i var-i)))))))
3378 (put 'calcFunc-tanh 'math-inverse-sign 1)
3379
3380 (put 'calcFunc-arcsinh 'math-inverse
3381 (function (lambda (x) (math-normalize (list 'calcFunc-sinh x)))))
3382 (put 'calcFunc-arcsinh 'math-inverse-sign 1)
3383
3384 (put 'calcFunc-arccosh 'math-inverse
3385 (function (lambda (x) (math-normalize (list 'calcFunc-cosh x)))))
3386
3387 (put 'calcFunc-arctanh 'math-inverse
3388 (function (lambda (x) (math-normalize (list 'calcFunc-tanh x)))))
3389 (put 'calcFunc-arctanh 'math-inverse-sign 1)
3390
3391
3392
3393 (defun calcFunc-taylor (expr var num)
3394 (let ((x0 0) (v var))
3395 (if (memq (car-safe var) '(+ - calcFunc-eq))
3396 (setq x0 (if (eq (car var) '+) (math-neg (nth 2 var)) (nth 2 var))
3397 v (nth 1 var)))
3398 (or (and (eq (car-safe v) 'var)
3399 (math-expr-contains expr v)
3400 (natnump num)
3401 (let ((accum (math-expr-subst expr v x0))
3402 (var2 (if (eq (car var) 'calcFunc-eq)
3403 (cons '- (cdr var))
3404 var))
3405 (n 0)
3406 (nfac 1)
3407 (fprime expr))
3408 (while (and (<= (setq n (1+ n)) num)
3409 (setq fprime (calcFunc-deriv fprime v nil t)))
3410 (setq fprime (math-simplify fprime)
3411 nfac (math-mul nfac n)
3412 accum (math-add accum
3413 (math-div (math-mul (math-pow var2 n)
3414 (math-expr-subst
3415 fprime v x0))
3416 nfac))))
3417 (and fprime
3418 (math-normalize accum))))
3419 (list 'calcFunc-taylor expr var num))))
3420
3421 ;;; arch-tag: f2932ec8-dd63-418b-a542-11a644b9d4c4
3422 ;;; calcalg2.el ends here