emacs/lisp/calc/calc-alg.el

1943 lines
66 KiB
EmacsLisp

;;; calc-alg.el --- algebraic functions for Calc -*- lexical-binding:t -*-
;; Copyright (C) 1990-1993, 2001-2024 Free Software Foundation, Inc.
;; Author: David Gillespie <daveg@synaptics.com>
;; This file is part of GNU Emacs.
;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>.
;;; Commentary:
;;; Code:
;; This file is autoloaded from calc-ext.el.
(require 'calc-ext)
(require 'calc-macs)
;;; Algebra commands.
(defvar math-simplify-only)
(defun calc-alg-evaluate (arg)
(interactive "p")
(calc-slow-wrapper
(calc-with-default-simplification
(let ((math-simplify-only nil))
(calc-modify-simplify-mode arg)
(calc-enter-result 1 "dsmp" (calc-top 1))))))
(defvar calc-simplify-mode)
(defun calc-modify-simplify-mode (arg)
(if (= (math-abs arg) 2)
(setq calc-simplify-mode 'alg)
(if (>= (math-abs arg) 3)
(setq calc-simplify-mode 'ext)))
(if (< arg 0)
(setq calc-simplify-mode (list calc-simplify-mode))))
(defun calc-simplify ()
(interactive)
(calc-slow-wrapper
(let ((top (calc-top-n 1)))
(if (calc-is-inverse)
(setq top
(let ((calc-simplify-mode nil))
(math-normalize (math-trig-rewrite top)))))
(if (calc-is-hyperbolic)
(setq top
(let ((calc-simplify-mode nil))
(math-normalize (math-hyperbolic-trig-rewrite top)))))
(calc-with-default-simplification
(calc-enter-result 1 "simp" (math-simplify top))))))
(defun calc-simplify-extended ()
(interactive)
(calc-slow-wrapper
(calc-with-default-simplification
(calc-enter-result 1 "esmp" (math-simplify-extended (calc-top-n 1))))))
(defvar math-expand-formulas)
(defun calc-expand-formula (arg)
(interactive "p")
(calc-slow-wrapper
(calc-with-default-simplification
(let ((math-simplify-only nil))
(calc-modify-simplify-mode arg)
(calc-enter-result 1 "expf"
(if (> arg 0)
(let ((math-expand-formulas t))
(calc-top-n 1))
(let ((top (calc-top-n 1)))
(or (math-expand-formula top)
top))))))))
(defun calc-factor (arg)
(interactive "P")
(calc-slow-wrapper
(calc-unary-op "fctr" (if (calc-is-hyperbolic)
'calcFunc-factors 'calcFunc-factor)
arg)))
(defun calc-expand (n)
(interactive "P")
(calc-slow-wrapper
(calc-enter-result 1 "expa"
(append (list 'calcFunc-expand
(calc-top-n 1))
(and n (list (prefix-numeric-value n)))))))
;;; Write out powers (a*b*...)^n as a*b*...*a*b*...
(defun calcFunc-powerexpand (expr)
(math-normalize (math-map-tree 'math-powerexpand expr)))
(defun math-powerexpand (expr)
(if (eq (car-safe expr) '^)
(let ((n (nth 2 expr)))
(cond ((and (integerp n)
(> n 0))
(let ((i 1)
(a (nth 1 expr))
(prod (nth 1 expr)))
(while (< i n)
(setq prod (math-mul prod a))
(setq i (1+ i)))
prod))
((and (integerp n)
(< n 0))
(let ((i -1)
(a (math-pow (nth 1 expr) -1))
(prod (math-pow (nth 1 expr) -1)))
(while (> i n)
(setq prod (math-mul a prod))
(setq i (1- i)))
prod))
(t
expr)))
expr))
(defun calc-powerexpand ()
(interactive)
(calc-slow-wrapper
(calc-enter-result 1 "pexp"
(calcFunc-powerexpand (calc-top-n 1)))))
(defun calc-collect (&optional var)
(interactive "sCollect terms involving: ")
(calc-slow-wrapper
(if (or (equal var "") (equal var "$") (null var))
(calc-enter-result 2 "clct" (cons 'calcFunc-collect
(calc-top-list-n 2)))
(let ((var (math-read-expr var)))
(if (eq (car-safe var) 'error)
(error "Bad format in expression: %s" (nth 1 var)))
(calc-enter-result 1 "clct" (list 'calcFunc-collect
(calc-top-n 1)
var))))))
(defun calc-apart (arg)
(interactive "P")
(calc-slow-wrapper
(calc-unary-op "aprt" 'calcFunc-apart arg)))
(defun calc-normalize-rat (arg)
(interactive "P")
(calc-slow-wrapper
(calc-unary-op "nrat" 'calcFunc-nrat arg)))
(defun calc-poly-gcd (arg)
(interactive "P")
(calc-slow-wrapper
(calc-binary-op "pgcd" 'calcFunc-pgcd arg)))
(defvar calc-poly-div-remainder)
(defun calc-poly-div (arg)
(interactive "P")
(calc-slow-wrapper
(let ((calc-poly-div-remainder nil))
(calc-binary-op "pdiv" 'calcFunc-pdiv arg)
(if (and calc-poly-div-remainder (null arg))
(progn
(calc-clear-command-flag 'clear-message)
(calc-record calc-poly-div-remainder "prem")
(if (not (Math-zerop calc-poly-div-remainder))
(message "(Remainder was %s)"
(math-format-flat-expr calc-poly-div-remainder 0))
(message "(No remainder)")))))))
(defun calc-poly-rem (arg)
(interactive "P")
(calc-slow-wrapper
(calc-binary-op "prem" 'calcFunc-prem arg)))
(defun calc-poly-div-rem (arg)
(interactive "P")
(calc-slow-wrapper
(if (calc-is-hyperbolic)
(calc-binary-op "pdvr" 'calcFunc-pdivide arg)
(calc-binary-op "pdvr" 'calcFunc-pdivrem arg))))
(defun calc-substitute (&optional oldname newname)
(interactive "sSubstitute old: ")
(calc-slow-wrapper
(let (old new (num 1) expr)
(if (or (equal oldname "") (equal oldname "$") (null oldname))
(setq new (calc-top-n 1)
old (calc-top-n 2)
expr (calc-top-n 3)
num 3)
(or newname
(progn (calc-unread-command ?\C-a)
(setq newname (read-string (concat "Substitute old: "
oldname
", new: ")
oldname))))
(if (or (equal newname "") (equal newname "$") (null newname))
(setq new (calc-top-n 1)
expr (calc-top-n 2)
num 2)
(setq new (if (stringp newname) (math-read-expr newname) newname))
(if (eq (car-safe new) 'error)
(error "Bad format in expression: %s" (nth 1 new)))
(setq expr (calc-top-n 1)))
(setq old (if (stringp oldname) (math-read-expr oldname) oldname))
(if (eq (car-safe old) 'error)
(error "Bad format in expression: %s" (nth 1 old)))
(or (math-expr-contains expr old)
(error "No occurrences found")))
(calc-enter-result num "sbst" (math-expr-subst expr old new)))))
(defun calc-has-rules (name)
(setq name (calc-var-value name))
(and (consp name)
(memq (car name) '(vec calcFunc-assign calcFunc-condition))
name))
;; math-eval-rules-cache and math-eval-rules-cache-other are
;; declared in calc.el, but are used here by math-recompile-eval-rules.
(defvar math-eval-rules-cache)
(defvar math-eval-rules-cache-other)
(defun math-recompile-eval-rules ()
(setq math-eval-rules-cache (and (calc-has-rules 'var-EvalRules)
(math-compile-rewrites
'(var EvalRules var-EvalRules)))
math-eval-rules-cache-other (assq nil math-eval-rules-cache)
math-eval-rules-cache-tag (calc-var-value 'var-EvalRules)))
;;; Try to expand a formula according to its definition.
(defun math-expand-formula (expr)
(and (consp expr)
(symbolp (car expr))
(or (get (car expr) 'calc-user-defn)
(get (car expr) 'math-expandable))
(let ((res (let ((math-expand-formulas t))
(apply (car expr) (cdr expr)))))
(and (not (eq (car-safe res) (car expr)))
res))))
;;; True if A comes before B in a canonical ordering of expressions. [P X X]
(defun math-beforep (a b) ; [Public]
(cond ((and (Math-realp a) (Math-realp b))
(let ((comp (math-compare a b)))
(or (eq comp -1)
(and (eq comp 0)
(not (equal a b))
(> (length (memq (car-safe a)
'(nil frac float)))
(length (memq (car-safe b)
'(nil frac float))))))))
((equal b '(neg (var inf var-inf))) nil)
((equal a '(neg (var inf var-inf))) t)
((equal a '(var inf var-inf)) nil)
((equal b '(var inf var-inf)) t)
((Math-realp a)
(if (and (eq (car-safe b) 'intv) (math-intv-constp b))
(if (or (math-beforep a (nth 2 b)) (Math-equal a (nth 2 b)))
t
nil)
t))
((Math-realp b)
(if (and (eq (car-safe a) 'intv) (math-intv-constp a))
(if (math-beforep (nth 2 a) b)
t
nil)
nil))
((and (eq (car a) 'intv) (eq (car b) 'intv)
(math-intv-constp a) (math-intv-constp b))
(let ((comp (math-compare (nth 2 a) (nth 2 b))))
(cond ((eq comp -1) t)
((eq comp 1) nil)
((and (memq (nth 1 a) '(2 3)) (memq (nth 1 b) '(0 1))) t)
((and (memq (nth 1 a) '(0 1)) (memq (nth 1 b) '(2 3))) nil)
((eq (setq comp (math-compare (nth 3 a) (nth 3 b))) -1) t)
((eq comp 1) nil)
((and (memq (nth 1 a) '(0 2)) (memq (nth 1 b) '(1 3))) t)
(t nil))))
((not (eq (not (Math-objectp a)) (not (Math-objectp b))))
(Math-objectp a))
((eq (car a) 'var)
(if (eq (car b) 'var)
(string-lessp (nth 1 a) (nth 1 b))
(not (Math-numberp b))))
((eq (car b) 'var) (Math-numberp a))
((eq (car a) (car b))
(while (and (setq a (cdr a) b (cdr b)) a
(equal (car a) (car b))))
(and b
(or (null a)
(math-beforep (car a) (car b)))))
(t (string-lessp (car a) (car b)))))
(defvar math-living-dangerously)
(defsubst math-simplify-extended (a)
(let ((math-living-dangerously t))
(math-simplify a)))
(defalias 'calcFunc-esimplify #'math-simplify-extended)
;;; Rewrite the trig functions in a form easier to simplify.
(defun math-trig-rewrite (fn)
"Rewrite trigonometric functions in terms of sines and cosines."
(cond
((not (consp fn))
fn)
((eq (car-safe fn) 'calcFunc-sec)
(list '/ 1 (cons 'calcFunc-cos (math-trig-rewrite (cdr fn)))))
((eq (car-safe fn) 'calcFunc-csc)
(list '/ 1 (cons 'calcFunc-sin (math-trig-rewrite (cdr fn)))))
((eq (car-safe fn) 'calcFunc-tan)
(let ((newfn (math-trig-rewrite (cdr fn))))
(list '/ (cons 'calcFunc-sin newfn)
(cons 'calcFunc-cos newfn))))
((eq (car-safe fn) 'calcFunc-cot)
(let ((newfn (math-trig-rewrite (cdr fn))))
(list '/ (cons 'calcFunc-cos newfn)
(cons 'calcFunc-sin newfn))))
(t
(mapcar #'math-trig-rewrite fn))))
(defun math-hyperbolic-trig-rewrite (fn)
"Rewrite hyperbolic functions in terms of sinhs and coshs."
(cond
((not (consp fn))
fn)
((eq (car-safe fn) 'calcFunc-sech)
(list '/ 1 (cons 'calcFunc-cosh (math-hyperbolic-trig-rewrite (cdr fn)))))
((eq (car-safe fn) 'calcFunc-csch)
(list '/ 1 (cons 'calcFunc-sinh (math-hyperbolic-trig-rewrite (cdr fn)))))
((eq (car-safe fn) 'calcFunc-tanh)
(let ((newfn (math-hyperbolic-trig-rewrite (cdr fn))))
(list '/ (cons 'calcFunc-sinh newfn)
(cons 'calcFunc-cosh newfn))))
((eq (car-safe fn) 'calcFunc-coth)
(let ((newfn (math-hyperbolic-trig-rewrite (cdr fn))))
(list '/ (cons 'calcFunc-cosh newfn)
(cons 'calcFunc-sinh newfn))))
(t
(mapcar #'math-hyperbolic-trig-rewrite fn))))
;; math-top-only is local to math-simplify, but is used by
;; math-simplify-step, which is called by math-simplify.
(defvar math-top-only)
(defun calc-input-angle-units (input)
(cond ((math-expr-contains input '(var deg var-deg)) 'deg)
((math-expr-contains input '(var rad var-rad)) 'rad)
((math-expr-contains input '(var hms var-hms)) 'hms)
(t nil)))
;; math-normalize-error is declared in calc.el.
(defvar math-normalize-error)
(defvar math-simplifying)
(defvar calc-angle-mode)
(defun math-simplify (top-expr)
(let ((math-simplifying t)
(calc-angle-mode (if (calc-input-angle-units top-expr)
'rad
calc-angle-mode))
(math-top-only (consp calc-simplify-mode))
(simp-rules (append (and (calc-has-rules 'var-AlgSimpRules)
'((var AlgSimpRules var-AlgSimpRules)))
(and math-living-dangerously
(calc-has-rules 'var-ExtSimpRules)
'((var ExtSimpRules var-ExtSimpRules)))
(and math-simplifying-units
(calc-has-rules 'var-UnitSimpRules)
'((var UnitSimpRules var-UnitSimpRules)))
(and math-integrating
(calc-has-rules 'var-IntegSimpRules)
'((var IntegSimpRules var-IntegSimpRules)))))
res)
(if math-top-only
(let ((r simp-rules))
(setq res (math-simplify-step (math-normalize top-expr))
calc-simplify-mode '(nil)
top-expr (math-normalize res))
(while r
(setq top-expr (math-rewrite top-expr (car r)
'(neg (var inf var-inf)))
r (cdr r))))
(calc-with-default-simplification
(while (let ((r simp-rules))
(setq res (math-normalize top-expr))
(if (not math-normalize-error)
(progn
(while r
(setq res (math-rewrite res (car r))
r (cdr r)))
(not (equal top-expr (setq res (math-simplify-step res)))))))
(setq top-expr res)))))
top-expr)
(defalias 'calcFunc-simplify #'math-simplify)
;; The following has a "bug" in that if any recursive simplifications
;; occur only the first handler will be tried; this doesn't really
;; matter, since math-simplify-step is iterated to a fixed point anyway.
(defun math-simplify-step (a)
(if (Math-primp a)
a
(let ((aa (if (or math-top-only
(memq (car a) '(calcFunc-quote calcFunc-condition
calcFunc-evalto)))
a
(cons (car a) (mapcar #'math-simplify-step (cdr a))))))
(and (symbolp (car aa))
(let ((handler (get (car aa) 'math-simplify)))
(and handler
(while (and handler
(equal (setq aa (or (funcall (car handler) aa)
aa))
a))
(setq handler (cdr handler))))))
aa)))
(defmacro math-defsimplify (funcs &rest code)
"Define the simplification code for functions FUNCS.
Code can refer to the expression to simplify via lexical variable `expr'
and should return the simplified expression to use (or nil)."
(declare (indent 1) (debug (sexp body)))
(cons 'progn
(mapcar (lambda (func)
`(put ',func 'math-simplify
(nconc
(get ',func 'math-simplify)
(list
(lambda (expr) ,@code)))))
(if (symbolp funcs) (list funcs) funcs))))
(math-defsimplify (+ -)
(cond ((and (memq (car-safe (nth 1 expr)) '(+ -))
(Math-numberp (nth 2 (nth 1 expr)))
(not (Math-numberp (nth 2 expr))))
(let ((x (nth 2 expr))
(op (car expr)))
(setcar (cdr (cdr expr)) (nth 2 (nth 1 expr)))
(setcar expr (car (nth 1 expr)))
(setcar (cdr (cdr (nth 1 expr))) x)
(setcar (nth 1 expr) op)))
((and (eq (car expr) '+)
(Math-numberp (nth 1 expr))
(not (Math-numberp (nth 2 expr))))
(let ((x (nth 2 expr)))
(setcar (cdr (cdr expr)) (nth 1 expr))
(setcar (cdr expr) x))))
(let ((aa expr)
aaa temp)
(while (memq (car-safe (setq aaa (nth 1 aa))) '(+ -))
(if (setq temp (math-combine-sum (nth 2 aaa) (nth 2 expr)
(eq (car aaa) '-)
(eq (car expr) '-) t))
(progn
(setcar (cdr (cdr expr)) temp)
(setcar expr '+)
(setcar (cdr (cdr aaa)) 0)))
(setq aa (nth 1 aa)))
(if (setq temp (math-combine-sum aaa (nth 2 expr)
nil (eq (car expr) '-) t))
(progn
(setcar (cdr (cdr expr)) temp)
(setcar expr '+)
(setcar (cdr aa) 0)))
expr))
(math-defsimplify *
(if (eq (car-safe (nth 2 expr)) '*)
(and (math-beforep (nth 1 (nth 2 expr)) (nth 1 expr))
(or (math-known-scalarp (nth 1 expr) t)
(math-known-scalarp (nth 1 (nth 2 expr)) t))
(let ((x (nth 1 expr)))
(setcar (cdr expr) (nth 1 (nth 2 expr)))
(setcar (cdr (nth 2 expr)) x)))
(and (math-beforep (nth 2 expr) (nth 1 expr))
(or (math-known-scalarp (nth 1 expr) t)
(math-known-scalarp (nth 2 expr) t))
(let ((x (nth 2 expr)))
(setcar (cdr (cdr expr)) (nth 1 expr))
(setcar (cdr expr) x))))
(let ((aa expr)
aaa temp
(safe t) (scalar (math-known-scalarp (nth 1 expr))))
(if (and (Math-ratp (nth 1 expr))
(setq temp (math-common-constant-factor (nth 2 expr))))
(progn
(setcar (cdr (cdr expr))
(math-cancel-common-factor (nth 2 expr) temp))
(setcar (cdr expr) (math-mul (nth 1 expr) temp))))
(while (and (eq (car-safe (setq aaa (nth 2 aa))) '*)
safe)
(if (setq temp (math-combine-prod (nth 1 expr)
(nth 1 aaa) nil nil t))
(progn
(setcar (cdr expr) temp)
(setcar (cdr aaa) 1)))
(setq safe (or scalar (math-known-scalarp (nth 1 aaa) t))
aa (nth 2 aa)))
(if (and (setq temp (math-combine-prod aaa (nth 1 expr) nil nil t))
safe)
(progn
(setcar (cdr expr) temp)
(setcar (cdr (cdr aa)) 1)))
(if (and (eq (car-safe (nth 1 expr)) 'frac)
(memq (nth 1 (nth 1 expr)) '(1 -1)))
(math-div (math-mul (nth 2 expr)
(nth 1 (nth 1 expr)))
(nth 2 (nth 1 expr)))
expr)))
(math-defsimplify /
(math-simplify-divide expr))
(defvar math--simplify-divide-expr)
(defun math-simplify-divide (expr)
(let ((np (cdr expr))
(nover nil)
(nn (and (or (eq (car expr) '/)
(not (Math-realp (nth 2 expr))))
(math-common-constant-factor (nth 2 expr))))
n op)
(if nn
(progn
(setq n (and (or (eq (car expr) '/)
(not (Math-realp (nth 1 expr))))
(math-common-constant-factor (nth 1 expr))))
(if (and (eq (car-safe nn) 'frac) (eq (nth 1 nn) 1) (not n))
(unless (and (eq (car-safe expr) 'calcFunc-eq)
(eq (car-safe (nth 1 expr)) 'var)
(not (math-expr-contains (nth 2 expr)
(nth 1 expr))))
(setcar (cdr expr)
(math-mul (nth 2 nn) (nth 1 expr)))
(setcar (cdr (cdr expr))
(math-cancel-common-factor (nth 2 expr) nn))
(if (and (math-negp nn)
(setq op (assq (car expr) calc-tweak-eqn-table)))
(setcar expr (nth 1 op))))
(if (and n (not (eq (setq n (math-frac-gcd n nn)) 1)))
(progn
(setcar (cdr expr)
(math-cancel-common-factor (nth 1 expr) n))
(setcar (cdr (cdr expr))
(math-cancel-common-factor (nth 2 expr) n))
(if (and (math-negp n)
(setq op (assq (car expr)
calc-tweak-eqn-table)))
(setcar expr (nth 1 op))))))))
(let ((math--simplify-divide-expr expr)) ;For use in math-simplify-divisor
(if (and (eq (car-safe (car np)) '/)
(math-known-scalarp (nth 2 expr) t))
(progn
(setq np (cdr (nth 1 expr)))
(while (eq (car-safe (setq n (car np))) '*)
(and (math-known-scalarp (nth 2 n) t)
(math-simplify-divisor (cdr n) (cdr (cdr expr)) nil t))
(setq np (cdr (cdr n))))
(math-simplify-divisor np (cdr (cdr expr)) nil t)
(setq nover t
np (cdr (cdr (nth 1 expr))))))
(while (eq (car-safe (setq n (car np))) '*)
(and (math-known-scalarp (nth 2 n) t)
(math-simplify-divisor (cdr n) (cdr (cdr expr)) nover t))
(setq np (cdr (cdr n))))
(math-simplify-divisor np (cdr (cdr expr)) nover t)
expr)))
;; The variables math-simplify-divisor-nover and math-simplify-divisor-dover
;; are local variables for math-simplify-divisor, but are used by
;; math-simplify-one-divisor.
(defvar math-simplify-divisor-nover)
(defvar math-simplify-divisor-dover)
(defun math-simplify-divisor (np dp nover dover)
(cond ((eq (car-safe (car dp)) '/)
(math-simplify-divisor np (cdr (car dp))
nover dover)
(and (math-known-scalarp (nth 1 (car dp)) t)
(math-simplify-divisor np (cdr (cdr (car dp)))
nover (not dover))))
((or (or (eq (car math--simplify-divide-expr) '/)
(let ((signs (math-possible-signs (car np))))
(or (memq signs '(1 4))
(and (memq (car math--simplify-divide-expr)
'(calcFunc-eq calcFunc-neq))
(eq signs 5))
math-living-dangerously)))
(math-numberp (car np)))
(let (d
(safe t)
(math-simplify-divisor-nover nover)
(math-simplify-divisor-dover dover)
(scalar (math-known-scalarp (car np))))
(while (and (eq (car-safe (setq d (car dp))) '*)
safe)
(math-simplify-one-divisor np (cdr d))
(setq safe (or scalar (math-known-scalarp (nth 1 d) t))
dp (cdr (cdr d))))
(if safe
(math-simplify-one-divisor np dp))))))
(defun math-simplify-one-divisor (np dp)
(let ((temp (math-combine-prod (car np) (car dp) math-simplify-divisor-nover
math-simplify-divisor-dover t))
op)
(if temp
(progn
(and (not (memq (car math--simplify-divide-expr)
'(/ calcFunc-eq calcFunc-neq)))
(math-known-negp (car dp))
(setq op (assq (car math--simplify-divide-expr)
calc-tweak-eqn-table))
(setcar math--simplify-divide-expr (nth 1 op)))
(setcar np (if math-simplify-divisor-nover (math-div 1 temp) temp))
(setcar dp 1))
(and math-simplify-divisor-dover (not math-simplify-divisor-nover)
(eq (car math--simplify-divide-expr) '/)
(eq (car-safe (car dp)) 'calcFunc-sqrt)
(Math-integerp (nth 1 (car dp)))
(progn
(setcar np (math-mul (car np)
(list 'calcFunc-sqrt (nth 1 (car dp)))))
(setcar dp (nth 1 (car dp))))))))
(defun math-common-constant-factor (expr)
(if (Math-realp expr)
(if (Math-ratp expr)
(and (not (memq expr '(0 1 -1)))
(math-abs expr))
(if (math-ratp (setq expr (math-to-simple-fraction expr)))
(math-common-constant-factor expr)))
(if (memq (car expr) '(+ - cplx sdev))
(let ((f1 (math-common-constant-factor (nth 1 expr)))
(f2 (math-common-constant-factor (nth 2 expr))))
(and f1 f2
(not (eq (setq f1 (math-frac-gcd f1 f2)) 1))
f1))
(if (memq (car expr) '(* polar))
(math-common-constant-factor (nth 1 expr))
(if (eq (car expr) '/)
(or (math-common-constant-factor (nth 1 expr))
(and (Math-integerp (nth 2 expr))
(list 'frac 1 (math-abs (nth 2 expr))))))))))
(defun math-cancel-common-factor (expr val)
(if (memq (car-safe expr) '(+ - cplx sdev))
(progn
(setcar (cdr expr) (math-cancel-common-factor (nth 1 expr) val))
(setcar (cdr (cdr expr)) (math-cancel-common-factor (nth 2 expr) val))
expr)
(if (eq (car-safe expr) '*)
(math-mul (math-cancel-common-factor (nth 1 expr) val) (nth 2 expr))
(math-div expr val))))
(defun math-frac-gcd (a b)
(if (Math-zerop a)
b
(if (Math-zerop b)
a
(if (and (Math-integerp a)
(Math-integerp b))
(math-gcd a b)
(and (Math-integerp a) (setq a (list 'frac a 1)))
(and (Math-integerp b) (setq b (list 'frac b 1)))
(math-make-frac (math-gcd (nth 1 a) (nth 1 b))
(math-gcd (nth 2 a) (nth 2 b)))))))
(defvar calc-prefer-frac)
(math-defsimplify %
(and (Math-realp (nth 2 expr))
(Math-posp (nth 2 expr))
(let ((lin (math-is-linear (nth 1 expr)))
t1)
(or (and lin
(or (math-negp (car lin))
(not (Math-lessp (car lin) (nth 2 expr))))
(list '%
(list '+
(math-mul (nth 1 lin) (nth 2 lin))
(math-mod (car lin) (nth 2 expr)))
(nth 2 expr)))
(and lin
(not (math-equal-int (nth 1 lin) 1))
(math-num-integerp (nth 1 lin))
(math-num-integerp (nth 2 expr))
(setq t1 (calcFunc-gcd (nth 1 lin) (nth 2 expr)))
(not (math-equal-int t1 1))
(list '*
t1
(list '%
(list '+
(math-mul (math-div (nth 1 lin) t1)
(nth 2 lin))
(let ((calc-prefer-frac t))
(math-div (car lin) t1)))
(math-div (nth 2 expr) t1))))
(and (math-equal-int (nth 2 expr) 1)
(math-known-integerp (if lin
(math-mul (nth 1 lin) (nth 2 lin))
(nth 1 expr)))
(if lin (math-mod (car lin) 1) 0))))))
(math-defsimplify (calcFunc-eq calcFunc-neq calcFunc-lt
calcFunc-gt calcFunc-leq calcFunc-geq)
(if (= (length expr) 3)
(math-simplify-ineq expr)))
(defun math-simplify-ineq (expr)
(let ((np (cdr expr))
n)
(while (memq (car-safe (setq n (car np))) '(+ -))
(math-simplify-add-term (cdr (cdr n)) (cdr (cdr expr))
(eq (car n) '-) nil)
(setq np (cdr n)))
(math-simplify-add-term np (cdr (cdr expr)) nil
(eq np (cdr expr)))
(math-simplify-divide expr)
(let ((signs (math-possible-signs (cons '- (cdr expr)))))
(or (cond ((eq (car expr) 'calcFunc-eq)
(or (and (eq signs 2) 1)
(and (memq signs '(1 4 5)) 0)))
((eq (car expr) 'calcFunc-neq)
(or (and (eq signs 2) 0)
(and (memq signs '(1 4 5)) 1)))
((eq (car expr) 'calcFunc-lt)
(or (and (eq signs 1) 1)
(and (memq signs '(2 4 6)) 0)))
((eq (car expr) 'calcFunc-gt)
(or (and (eq signs 4) 1)
(and (memq signs '(1 2 3)) 0)))
((eq (car expr) 'calcFunc-leq)
(or (and (eq signs 4) 0)
(and (memq signs '(1 2 3)) 1)))
((eq (car expr) 'calcFunc-geq)
(or (and (eq signs 1) 0)
(and (memq signs '(2 4 6)) 1))))
expr))))
(defun math-simplify-add-term (np dp minus lplain)
(or (math-vectorp (car np))
(let ((rplain t)
n d temp)
(while (memq (car-safe (setq n (car np) d (car dp))) '(+ -))
(setq rplain nil)
(if (setq temp (math-combine-sum n (nth 2 d)
minus (eq (car d) '+) t))
(if (or lplain (eq (math-looks-negp temp) minus))
(progn
(setcar np (setq n (if minus (math-neg temp) temp)))
(setcar (cdr (cdr d)) 0))
(progn
(setcar np 0)
(setcar (cdr (cdr d)) (setq n (if (eq (car d) '+)
(math-neg temp)
temp))))))
(setq dp (cdr d)))
(if (setq temp (math-combine-sum n d minus t t))
(if (or lplain
(and (not rplain)
(eq (math-looks-negp temp) minus)))
(progn
(setcar np (setq n (if minus (math-neg temp) temp)))
(setcar dp 0))
(progn
(setcar np 0)
(setcar dp (setq n (math-neg temp)))))))))
(math-defsimplify calcFunc-sin
(or (and (eq (car-safe (nth 1 expr)) 'calcFunc-arcsin)
(nth 1 (nth 1 expr)))
(and (math-looks-negp (nth 1 expr))
(math-neg (list 'calcFunc-sin (math-neg (nth 1 expr)))))
(and (eq calc-angle-mode 'rad)
(let ((n (math-linear-in (nth 1 expr) '(var pi var-pi))))
(and n
(math-known-sin (car n) (nth 1 n) 120 0))))
(and (eq calc-angle-mode 'deg)
(let ((n (math-integer-plus (nth 1 expr))))
(and n
(math-known-sin (car n) (nth 1 n) '(frac 2 3) 0))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-arccos)
(list 'calcFunc-sqrt (math-sub 1 (math-sqr
(nth 1 (nth 1 expr))))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-arctan)
(math-div (nth 1 (nth 1 expr))
(list 'calcFunc-sqrt
(math-add 1 (math-sqr
(nth 1 (nth 1 expr)))))))
(let ((m (math-should-expand-trig (nth 1 expr))))
(and m (integerp (car m))
(let ((n (car m)) (a (nth 1 m)))
(list '+
(list '* (list 'calcFunc-sin (list '* (1- n) a))
(list 'calcFunc-cos a))
(list '* (list 'calcFunc-cos (list '* (1- n) a))
(list 'calcFunc-sin a))))))))
(math-defsimplify calcFunc-cos
(or (and (eq (car-safe (nth 1 expr)) 'calcFunc-arccos)
(nth 1 (nth 1 expr)))
(and (math-looks-negp (nth 1 expr))
(list 'calcFunc-cos (math-neg (nth 1 expr))))
(and (eq calc-angle-mode 'rad)
(let ((n (math-linear-in (nth 1 expr) '(var pi var-pi))))
(and n
(math-known-sin (car n) (nth 1 n) 120 300))))
(and (eq calc-angle-mode 'deg)
(let ((n (math-integer-plus (nth 1 expr))))
(and n
(math-known-sin (car n) (nth 1 n) '(frac 2 3) 300))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-arcsin)
(list 'calcFunc-sqrt
(math-sub 1 (math-sqr (nth 1 (nth 1 expr))))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-arctan)
(math-div 1
(list 'calcFunc-sqrt
(math-add 1
(math-sqr (nth 1 (nth 1 expr)))))))
(let ((m (math-should-expand-trig (nth 1 expr))))
(and m (integerp (car m))
(let ((n (car m)) (a (nth 1 m)))
(list '-
(list '* (list 'calcFunc-cos (list '* (1- n) a))
(list 'calcFunc-cos a))
(list '* (list 'calcFunc-sin (list '* (1- n) a))
(list 'calcFunc-sin a))))))))
(math-defsimplify calcFunc-sec
(or (and (math-looks-negp (nth 1 expr))
(list 'calcFunc-sec (math-neg (nth 1 expr))))
(and (eq calc-angle-mode 'rad)
(let ((n (math-linear-in (nth 1 expr) '(var pi var-pi))))
(and n
(let ((s (math-known-sin (car n) (nth 1 n) 120 300)))
(and s (math-div 1 s))))))
(and (eq calc-angle-mode 'deg)
(let ((n (math-integer-plus (nth 1 expr))))
(and n
(let ((s (math-known-sin (car n) (nth 1 n) '(frac 2 3) 300)))
(and s (math-div 1 s))))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-arcsin)
(math-div
1
(list 'calcFunc-sqrt
(math-sub 1 (math-sqr (nth 1 (nth 1 expr)))))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-arccos)
(math-div
1
(nth 1 (nth 1 expr))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-arctan)
(list 'calcFunc-sqrt
(math-add 1
(math-sqr (nth 1 (nth 1 expr))))))))
(math-defsimplify calcFunc-csc
(or (and (math-looks-negp (nth 1 expr))
(math-neg (list 'calcFunc-csc (math-neg (nth 1 expr)))))
(and (eq calc-angle-mode 'rad)
(let ((n (math-linear-in (nth 1 expr) '(var pi var-pi))))
(and n
(let ((s (math-known-sin (car n) (nth 1 n) 120 0)))
(and s (math-div 1 s))))))
(and (eq calc-angle-mode 'deg)
(let ((n (math-integer-plus (nth 1 expr))))
(and n
(let ((s (math-known-sin (car n) (nth 1 n) '(frac 2 3) 0)))
(and s (math-div 1 s))))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-arcsin)
(math-div 1 (nth 1 (nth 1 expr))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-arccos)
(math-div
1
(list 'calcFunc-sqrt (math-sub 1 (math-sqr
(nth 1 (nth 1 expr)))))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-arctan)
(math-div (list 'calcFunc-sqrt
(math-add 1 (math-sqr
(nth 1 (nth 1 expr)))))
(nth 1 (nth 1 expr))))))
(defun math-should-expand-trig (x &optional hyperbolic)
(let ((m (math-is-multiple x)))
(and math-living-dangerously
m (or (and (integerp (car m)) (> (car m) 1))
(equal (car m) '(frac 1 2)))
(or math-integrating
(memq (car-safe (nth 1 m))
(if hyperbolic
'(calcFunc-arcsinh calcFunc-arccosh calcFunc-arctanh)
'(calcFunc-arcsin calcFunc-arccos calcFunc-arctan)))
(and (eq (car-safe (nth 1 m)) 'calcFunc-ln)
(eq hyperbolic 'exp)))
m)))
(defun math-known-sin (plus n mul off)
(setq n (math-mul n mul))
(and (math-num-integerp n)
(setq n (math-mod (math-add (math-trunc n) off) 240))
(if (>= n 120)
(and (setq n (math-known-sin plus (- n 120) 1 0))
(math-neg n))
(if (> n 60)
(setq n (- 120 n)))
(if (math-zerop plus)
(and (or calc-symbolic-mode
(memq n '(0 20 60)))
(cdr (assq n
'( (0 . 0)
(10 . (/ (calcFunc-sqrt
(- 2 (calcFunc-sqrt 3))) 2))
(12 . (/ (- (calcFunc-sqrt 5) 1) 4))
(15 . (/ (calcFunc-sqrt
(- 2 (calcFunc-sqrt 2))) 2))
(20 . (/ 1 2))
(24 . (* (^ (/ 1 2) (/ 3 2))
(calcFunc-sqrt
(- 5 (calcFunc-sqrt 5)))))
(30 . (/ (calcFunc-sqrt 2) 2))
(36 . (/ (+ (calcFunc-sqrt 5) 1) 4))
(40 . (/ (calcFunc-sqrt 3) 2))
(45 . (/ (calcFunc-sqrt
(+ 2 (calcFunc-sqrt 2))) 2))
(48 . (* (^ (/ 1 2) (/ 3 2))
(calcFunc-sqrt
(+ 5 (calcFunc-sqrt 5)))))
(50 . (/ (calcFunc-sqrt
(+ 2 (calcFunc-sqrt 3))) 2))
(60 . 1)))))
(cond ((eq n 0) (math-normalize (list 'calcFunc-sin plus)))
((eq n 60) (math-normalize (list 'calcFunc-cos plus)))
(t nil))))))
(math-defsimplify calcFunc-tan
(or (and (eq (car-safe (nth 1 expr)) 'calcFunc-arctan)
(nth 1 (nth 1 expr)))
(and (math-looks-negp (nth 1 expr))
(math-neg (list 'calcFunc-tan (math-neg (nth 1 expr)))))
(and (eq calc-angle-mode 'rad)
(let ((n (math-linear-in (nth 1 expr) '(var pi var-pi))))
(and n
(math-known-tan (car n) (nth 1 n) 120))))
(and (eq calc-angle-mode 'deg)
(let ((n (math-integer-plus (nth 1 expr))))
(and n
(math-known-tan (car n) (nth 1 n) '(frac 2 3)))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-arcsin)
(math-div (nth 1 (nth 1 expr))
(list 'calcFunc-sqrt
(math-sub 1 (math-sqr (nth 1 (nth 1 expr)))))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-arccos)
(math-div (list 'calcFunc-sqrt
(math-sub 1 (math-sqr (nth 1 (nth 1 expr)))))
(nth 1 (nth 1 expr))))
(let ((m (math-should-expand-trig (nth 1 expr))))
(and m
(if (equal (car m) '(frac 1 2))
(math-div (math-sub 1 (list 'calcFunc-cos (nth 1 m)))
(list 'calcFunc-sin (nth 1 m)))
(math-div (list 'calcFunc-sin (nth 1 expr))
(list 'calcFunc-cos (nth 1 expr))))))))
(math-defsimplify calcFunc-cot
(or (and (math-looks-negp (nth 1 expr))
(math-neg (list 'calcFunc-cot (math-neg (nth 1 expr)))))
(and (eq calc-angle-mode 'rad)
(let ((n (math-linear-in (nth 1 expr) '(var pi var-pi))))
(and n
(let ((tn (math-known-tan (car n) (nth 1 n) 120)))
(and tn (math-div 1 tn))))))
(and (eq calc-angle-mode 'deg)
(let ((n (math-integer-plus (nth 1 expr))))
(and n
(let ((tn (math-known-tan (car n) (nth 1 n) '(frac 2 3))))
(and tn (math-div 1 tn))))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-arcsin)
(math-div (list 'calcFunc-sqrt
(math-sub 1 (math-sqr (nth 1 (nth 1 expr)))))
(nth 1 (nth 1 expr))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-arccos)
(math-div (nth 1 (nth 1 expr))
(list 'calcFunc-sqrt
(math-sub 1 (math-sqr (nth 1 (nth 1 expr)))))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-arctan)
(math-div 1 (nth 1 (nth 1 expr))))))
(defun math-known-tan (plus n mul)
(setq n (math-mul n mul))
(and (math-num-integerp n)
(setq n (math-mod (math-trunc n) 120))
(if (> n 60)
(and (setq n (math-known-tan plus (- 120 n) 1))
(math-neg n))
(if (math-zerop plus)
(and (or calc-symbolic-mode
(memq n '(0 30 60)))
(cdr (assq n '( (0 . 0)
(10 . (- 2 (calcFunc-sqrt 3)))
(12 . (calcFunc-sqrt
(- 1 (* (/ 2 5) (calcFunc-sqrt 5)))))
(15 . (- (calcFunc-sqrt 2) 1))
(20 . (/ (calcFunc-sqrt 3) 3))
(24 . (calcFunc-sqrt
(- 5 (* 2 (calcFunc-sqrt 5)))))
(30 . 1)
(36 . (calcFunc-sqrt
(+ 1 (* (/ 2 5) (calcFunc-sqrt 5)))))
(40 . (calcFunc-sqrt 3))
(45 . (+ (calcFunc-sqrt 2) 1))
(48 . (calcFunc-sqrt
(+ 5 (* 2 (calcFunc-sqrt 5)))))
(50 . (+ 2 (calcFunc-sqrt 3)))
(60 . (var uinf var-uinf))))))
(cond ((eq n 0) (math-normalize (list 'calcFunc-tan plus)))
((eq n 60) (math-normalize (list '/ -1
(list 'calcFunc-tan plus))))
(t nil))))))
(math-defsimplify calcFunc-sinh
(or (and (eq (car-safe (nth 1 expr)) 'calcFunc-arcsinh)
(nth 1 (nth 1 expr)))
(and (math-looks-negp (nth 1 expr))
(math-neg (list 'calcFunc-sinh (math-neg (nth 1 expr)))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-arccosh)
math-living-dangerously
(list 'calcFunc-sqrt
(math-sub (math-sqr (nth 1 (nth 1 expr))) 1)))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-arctanh)
math-living-dangerously
(math-div (nth 1 (nth 1 expr))
(list 'calcFunc-sqrt
(math-sub 1 (math-sqr (nth 1 (nth 1 expr)))))))
(let ((m (math-should-expand-trig (nth 1 expr) t)))
(and m (integerp (car m))
(let ((n (car m)) (a (nth 1 m)))
(if (> n 1)
(list '+
(list '* (list 'calcFunc-sinh (list '* (1- n) a))
(list 'calcFunc-cosh a))
(list '* (list 'calcFunc-cosh (list '* (1- n) a))
(list 'calcFunc-sinh a)))))))))
(math-defsimplify calcFunc-cosh
(or (and (eq (car-safe (nth 1 expr)) 'calcFunc-arccosh)
(nth 1 (nth 1 expr)))
(and (math-looks-negp (nth 1 expr))
(list 'calcFunc-cosh (math-neg (nth 1 expr))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-arcsinh)
math-living-dangerously
(list 'calcFunc-sqrt
(math-add (math-sqr (nth 1 (nth 1 expr))) 1)))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-arctanh)
math-living-dangerously
(math-div 1
(list 'calcFunc-sqrt
(math-sub 1 (math-sqr (nth 1 (nth 1 expr)))))))
(let ((m (math-should-expand-trig (nth 1 expr) t)))
(and m (integerp (car m))
(let ((n (car m)) (a (nth 1 m)))
(if (> n 1)
(list '+
(list '* (list 'calcFunc-cosh (list '* (1- n) a))
(list 'calcFunc-cosh a))
(list '* (list 'calcFunc-sinh (list '* (1- n) a))
(list 'calcFunc-sinh a)))))))))
(math-defsimplify calcFunc-tanh
(or (and (eq (car-safe (nth 1 expr)) 'calcFunc-arctanh)
(nth 1 (nth 1 expr)))
(and (math-looks-negp (nth 1 expr))
(math-neg (list 'calcFunc-tanh (math-neg (nth 1 expr)))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-arcsinh)
math-living-dangerously
(math-div (nth 1 (nth 1 expr))
(list 'calcFunc-sqrt
(math-add (math-sqr (nth 1 (nth 1 expr))) 1))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-arccosh)
math-living-dangerously
(math-div (list 'calcFunc-sqrt
(math-sub (math-sqr (nth 1 (nth 1 expr))) 1))
(nth 1 (nth 1 expr))))
(let ((m (math-should-expand-trig (nth 1 expr) t)))
(and m
(if (equal (car m) '(frac 1 2))
(math-div (math-sub (list 'calcFunc-cosh (nth 1 m)) 1)
(list 'calcFunc-sinh (nth 1 m)))
(math-div (list 'calcFunc-sinh (nth 1 expr))
(list 'calcFunc-cosh (nth 1 expr))))))))
(math-defsimplify calcFunc-sech
(or (and (math-looks-negp (nth 1 expr))
(list 'calcFunc-sech (math-neg (nth 1 expr))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-arcsinh)
math-living-dangerously
(math-div
1
(list 'calcFunc-sqrt
(math-add (math-sqr (nth 1 (nth 1 expr))) 1))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-arccosh)
math-living-dangerously
(math-div 1 (nth 1 (nth 1 expr))) 1)
(and (eq (car-safe (nth 1 expr)) 'calcFunc-arctanh)
math-living-dangerously
(list 'calcFunc-sqrt
(math-sub 1 (math-sqr (nth 1 (nth 1 expr))))))))
(math-defsimplify calcFunc-csch
(or (and (math-looks-negp (nth 1 expr))
(math-neg (list 'calcFunc-csch (math-neg (nth 1 expr)))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-arcsinh)
math-living-dangerously
(math-div 1 (nth 1 (nth 1 expr))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-arccosh)
math-living-dangerously
(math-div
1
(list 'calcFunc-sqrt
(math-sub (math-sqr (nth 1 (nth 1 expr))) 1))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-arctanh)
math-living-dangerously
(math-div (list 'calcFunc-sqrt
(math-sub 1 (math-sqr (nth 1 (nth 1 expr)))))
(nth 1 (nth 1 expr))))))
(math-defsimplify calcFunc-coth
(or (and (math-looks-negp (nth 1 expr))
(math-neg (list 'calcFunc-coth (math-neg (nth 1 expr)))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-arcsinh)
math-living-dangerously
(math-div (list 'calcFunc-sqrt
(math-add (math-sqr (nth 1 (nth 1 expr))) 1))
(nth 1 (nth 1 expr))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-arccosh)
math-living-dangerously
(math-div (nth 1 (nth 1 expr))
(list 'calcFunc-sqrt
(math-sub (math-sqr (nth 1 (nth 1 expr))) 1))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-arctanh)
math-living-dangerously
(math-div 1 (nth 1 (nth 1 expr))))))
(math-defsimplify calcFunc-arcsin
(or (and (math-looks-negp (nth 1 expr))
(math-neg (list 'calcFunc-arcsin (math-neg (nth 1 expr)))))
(and (eq (nth 1 expr) 1)
(math-quarter-circle t))
(and (equal (nth 1 expr) '(frac 1 2))
(math-div (math-half-circle t) 6))
(and math-living-dangerously
(eq (car-safe (nth 1 expr)) 'calcFunc-sin)
(nth 1 (nth 1 expr)))
(and math-living-dangerously
(eq (car-safe (nth 1 expr)) 'calcFunc-cos)
(math-sub (math-quarter-circle t)
(nth 1 (nth 1 expr))))))
(math-defsimplify calcFunc-arccos
(or (and (eq (nth 1 expr) 0)
(math-quarter-circle t))
(and (eq (nth 1 expr) -1)
(math-half-circle t))
(and (equal (nth 1 expr) '(frac 1 2))
(math-div (math-half-circle t) 3))
(and (equal (nth 1 expr) '(frac -1 2))
(math-div (math-mul (math-half-circle t) 2) 3))
(and math-living-dangerously
(eq (car-safe (nth 1 expr)) 'calcFunc-cos)
(nth 1 (nth 1 expr)))
(and math-living-dangerously
(eq (car-safe (nth 1 expr)) 'calcFunc-sin)
(math-sub (math-quarter-circle t)
(nth 1 (nth 1 expr))))))
(math-defsimplify calcFunc-arctan
(or (and (math-looks-negp (nth 1 expr))
(math-neg (list 'calcFunc-arctan (math-neg (nth 1 expr)))))
(and (eq (nth 1 expr) 1)
(math-div (math-half-circle t) 4))
(and math-living-dangerously
(eq (car-safe (nth 1 expr)) 'calcFunc-tan)
(nth 1 (nth 1 expr)))))
(math-defsimplify calcFunc-arcsinh
(or (and (math-looks-negp (nth 1 expr))
(math-neg (list 'calcFunc-arcsinh (math-neg (nth 1 expr)))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-sinh)
(or math-living-dangerously
(math-known-realp (nth 1 (nth 1 expr))))
(nth 1 (nth 1 expr)))))
(math-defsimplify calcFunc-arccosh
(and (eq (car-safe (nth 1 expr)) 'calcFunc-cosh)
(or math-living-dangerously
(math-known-realp (nth 1 (nth 1 expr))))
(nth 1 (nth 1 expr))))
(math-defsimplify calcFunc-arctanh
(or (and (math-looks-negp (nth 1 expr))
(math-neg (list 'calcFunc-arctanh (math-neg (nth 1 expr)))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-tanh)
(or math-living-dangerously
(math-known-realp (nth 1 (nth 1 expr))))
(nth 1 (nth 1 expr)))))
(math-defsimplify calcFunc-sqrt
(math-simplify-sqrt expr))
(defun math-simplify-sqrt (expr)
(or (and (eq (car-safe (nth 1 expr)) 'frac)
(math-div (list 'calcFunc-sqrt
(math-mul (nth 1 (nth 1 expr))
(nth 2 (nth 1 expr))))
(nth 2 (nth 1 expr))))
(let ((fac (if (math-objectp (nth 1 expr))
(math-squared-factor (nth 1 expr))
(math-common-constant-factor (nth 1 expr)))))
(and fac (not (eq fac 1))
(math-mul (math-normalize (list 'calcFunc-sqrt fac))
(math-normalize
(list 'calcFunc-sqrt
(math-cancel-common-factor
(nth 1 expr) fac))))))
(and math-living-dangerously
(or (and (eq (car-safe (nth 1 expr)) '-)
(math-equal-int (nth 1 (nth 1 expr)) 1)
(eq (car-safe (nth 2 (nth 1 expr))) '^)
(math-equal-int (nth 2 (nth 2 (nth 1 expr))) 2)
(or (and (eq (car-safe (nth 1 (nth 2 (nth 1 expr))))
'calcFunc-sin)
(list 'calcFunc-cos
(nth 1 (nth 1 (nth 2 (nth 1 expr))))))
(and (eq (car-safe (nth 1 (nth 2 (nth 1 expr))))
'calcFunc-cos)
(list 'calcFunc-sin
(nth 1 (nth 1 (nth 2
(nth 1 expr))))))))
(and (eq (car-safe (nth 1 expr)) '-)
(math-equal-int (nth 2 (nth 1 expr)) 1)
(eq (car-safe (nth 1 (nth 1 expr))) '^)
(math-equal-int (nth 2 (nth 1 (nth 1 expr))) 2)
(and (eq (car-safe (nth 1 (nth 1 (nth 1 expr))))
'calcFunc-cosh)
(list 'calcFunc-sinh
(nth 1 (nth 1 (nth 1 (nth 1 expr)))))))
(and (eq (car-safe (nth 1 expr)) '+)
(let ((a (nth 1 (nth 1 expr)))
(b (nth 2 (nth 1 expr))))
(and (or (and (math-equal-int a 1)
(setq a b b (nth 1 (nth 1 expr))))
(math-equal-int b 1))
(eq (car-safe a) '^)
(math-equal-int (nth 2 a) 2)
(or (and (eq (car-safe (nth 1 a)) 'calcFunc-sinh)
(list 'calcFunc-cosh (nth 1 (nth 1 a))))
(and (eq (car-safe (nth 1 a)) 'calcFunc-csch)
(list 'calcFunc-coth (nth 1 (nth 1 a))))
(and (eq (car-safe (nth 1 a)) 'calcFunc-tan)
(list '/ 1 (list 'calcFunc-cos
(nth 1 (nth 1 a)))))
(and (eq (car-safe (nth 1 a)) 'calcFunc-cot)
(list '/ 1 (list 'calcFunc-sin
(nth 1 (nth 1 a)))))))))
(and (eq (car-safe (nth 1 expr)) '^)
(list '^
(nth 1 (nth 1 expr))
(math-div (nth 2 (nth 1 expr)) 2)))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-sqrt)
(list '^ (nth 1 (nth 1 expr)) (math-div 1 4)))
(and (memq (car-safe (nth 1 expr)) '(* /))
(list (car (nth 1 expr))
(list 'calcFunc-sqrt (nth 1 (nth 1 expr)))
(list 'calcFunc-sqrt (nth 2 (nth 1 expr)))))
(and (memq (car-safe (nth 1 expr)) '(+ -))
(not (math-any-floats (nth 1 expr)))
(let ((f (calcFunc-factors (calcFunc-expand
(nth 1 expr)))))
(and (math-vectorp f)
(or (> (length f) 2)
(> (nth 2 (nth 1 f)) 1))
(let ((out 1) (rest 1) (sums 1) fac pow)
(while (setq f (cdr f))
(setq fac (nth 1 (car f))
pow (nth 2 (car f)))
(if (> pow 1)
(setq out (math-mul out (math-pow
fac (/ pow 2)))
pow (% pow 2)))
(if (> pow 0)
(if (memq (car-safe fac) '(+ -))
(setq sums (math-mul-thru sums fac))
(setq rest (math-mul rest fac)))))
(and (not (and (eq out 1) (memq rest '(1 -1))))
(math-mul
out
(list 'calcFunc-sqrt
(math-mul sums rest))))))))))))
;;; Rather than factoring x into primes, just check for the first ten primes.
(defun math-squared-factor (x)
(if (Math-integerp x)
(let ((prsqr '(4 9 25 49 121 169 289 361 529 841))
(fac 1)
res)
(while prsqr
(if (eq (cdr (setq res (math-idivmod x (car prsqr)))) 0)
(setq x (car res)
fac (math-mul fac (car prsqr)))
(setq prsqr (cdr prsqr))))
fac)))
(math-defsimplify calcFunc-exp
(math-simplify-exp (nth 1 expr)))
(defun math-simplify-exp (x)
(or (and (eq (car-safe x) 'calcFunc-ln)
(nth 1 x))
(and math-living-dangerously
(or (and (eq (car-safe x) 'calcFunc-arcsinh)
(math-add (nth 1 x)
(list 'calcFunc-sqrt
(math-add (math-sqr (nth 1 x)) 1))))
(and (eq (car-safe x) 'calcFunc-arccosh)
(math-add (nth 1 x)
(list 'calcFunc-sqrt
(math-sub (math-sqr (nth 1 x)) 1))))
(and (eq (car-safe x) 'calcFunc-arctanh)
(math-div (list 'calcFunc-sqrt (math-add 1 (nth 1 x)))
(list 'calcFunc-sqrt (math-sub 1 (nth 1 x)))))
(let ((m (math-should-expand-trig x 'exp)))
(and m (integerp (car m))
(list '^ (list 'calcFunc-exp (nth 1 m)) (car m))))))
(and calc-symbolic-mode
(math-known-imagp x)
(let* ((ip (calcFunc-im x))
(n (math-linear-in ip '(var pi var-pi)))
s c)
(and n
(setq s (math-known-sin (car n) (nth 1 n) 120 0))
(setq c (math-known-sin (car n) (nth 1 n) 120 300))
(list '+ c (list '* s '(var i var-i))))))))
(math-defsimplify calcFunc-ln
(or (and (eq (car-safe (nth 1 expr)) 'calcFunc-exp)
(or math-living-dangerously
(math-known-realp (nth 1 (nth 1 expr))))
(nth 1 (nth 1 expr)))
(and (eq (car-safe (nth 1 expr)) '^)
(equal (nth 1 (nth 1 expr)) '(var e var-e))
(or math-living-dangerously
(math-known-realp (nth 2 (nth 1 expr))))
(nth 2 (nth 1 expr)))
(and calc-symbolic-mode
(math-known-negp (nth 1 expr))
(math-add (list 'calcFunc-ln (math-neg (nth 1 expr)))
'(* (var pi var-pi) (var i var-i))))
(and calc-symbolic-mode
(math-known-imagp (nth 1 expr))
(let* ((ip (calcFunc-im (nth 1 expr)))
(ips (math-possible-signs ip)))
(or (and (memq ips '(4 6))
(math-add (list 'calcFunc-ln ip)
'(/ (* (var pi var-pi) (var i var-i)) 2)))
(and (memq ips '(1 3))
(math-sub (list 'calcFunc-ln (math-neg ip))
'(/ (* (var pi var-pi) (var i var-i)) 2))))))))
(math-defsimplify ^
(or (and math-living-dangerously
(or (and (eq (car-safe (nth 1 expr)) '^)
(list '^
(nth 1 (nth 1 expr))
(math-mul (nth 2 expr)
(nth 2 (nth 1 expr)))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-sqrt)
(list '^
(nth 1 (nth 1 expr))
(math-div (nth 2 expr) 2)))
(and (memq (car-safe (nth 1 expr)) '(* /))
(list (car (nth 1 expr))
(list '^ (nth 1 (nth 1 expr))
(nth 2 expr))
(list '^ (nth 2 (nth 1 expr))
(nth 2 expr))))))
(and (math-equal-int (nth 1 expr) 10)
(eq (car-safe (nth 2 expr)) 'calcFunc-log10)
(nth 1 (nth 2 expr)))
(and (equal (nth 1 expr) '(var e var-e))
(math-simplify-exp (nth 2 expr)))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-exp)
(not math-integrating)
(list 'calcFunc-exp (math-mul (nth 1 (nth 1 expr))
(nth 2 expr))))
(and (equal (nth 1 expr) '(var i var-i))
(math-imaginary-i)
(math-num-integerp (nth 2 expr))
(let ((x (math-mod (math-trunc (nth 2 expr)) 4)))
(cond ((eq x 0) 1)
((eq x 1) (nth 1 expr))
((eq x 2) -1)
((eq x 3) (math-neg (nth 1 expr))))))
(and math-integrating
(integerp (nth 2 expr))
(>= (nth 2 expr) 2)
(or (and (eq (car-safe (nth 1 expr)) 'calcFunc-cos)
(math-mul (math-pow (nth 1 expr)
(- (nth 2 expr) 2))
(math-sub 1
(math-sqr
(list 'calcFunc-sin
(nth 1 (nth 1 expr)))))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-cosh)
(math-mul (math-pow (nth 1 expr)
(- (nth 2 expr) 2))
(math-add 1
(math-sqr
(list 'calcFunc-sinh
(nth 1 (nth 1 expr)))))))))
(and (eq (car-safe (nth 2 expr)) 'frac)
(Math-ratp (nth 1 expr))
(Math-posp (nth 1 expr))
(if (equal (nth 2 expr) '(frac 1 2))
(list 'calcFunc-sqrt (nth 1 expr))
(let ((flr (math-floor (nth 2 expr))))
(and (not (Math-zerop flr))
(list '* (list '^ (nth 1 expr) flr)
(list '^ (nth 1 expr)
(math-sub (nth 2 expr) flr)))))))
(and (eq (math-quarter-integer (nth 2 expr)) 2)
(let ((temp (math-simplify-sqrt expr)))
(and temp
(list '^ temp (math-mul (nth 2 expr) 2)))))))
(math-defsimplify calcFunc-log10
(and (eq (car-safe (nth 1 expr)) '^)
(math-equal-int (nth 1 (nth 1 expr)) 10)
(or math-living-dangerously
(math-known-realp (nth 2 (nth 1 expr))))
(nth 2 (nth 1 expr))))
(math-defsimplify calcFunc-erf
(or (and (math-looks-negp (nth 1 expr))
(math-neg (list 'calcFunc-erf (math-neg (nth 1 expr)))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-conj)
(list 'calcFunc-conj
(list 'calcFunc-erf (nth 1 (nth 1 expr)))))))
(math-defsimplify calcFunc-erfc
(or (and (math-looks-negp (nth 1 expr))
(math-sub 2 (list 'calcFunc-erfc (math-neg (nth 1 expr)))))
(and (eq (car-safe (nth 1 expr)) 'calcFunc-conj)
(list 'calcFunc-conj
(list 'calcFunc-erfc (nth 1 (nth 1 expr)))))))
(defun math-linear-in (expr term &optional always)
(if (math-expr-contains expr term)
(let* ((calc-prefer-frac t)
(p (math-is-polynomial expr term 1)))
(and (cdr p)
p))
(and always (list expr 0))))
(defun math-multiple-of (expr term)
(let ((p (math-linear-in expr term)))
(and p
(math-zerop (car p))
(nth 1 p))))
; not perfect, but it'll do
(defun math-integer-plus (expr)
(cond ((Math-integerp expr)
(list 0 expr))
((and (memq (car expr) '(+ -))
(Math-integerp (nth 1 expr)))
(list (if (eq (car expr) '+) (nth 2 expr) (math-neg (nth 2 expr)))
(nth 1 expr)))
((and (memq (car expr) '(+ -))
(Math-integerp (nth 2 expr)))
(list (nth 1 expr)
(if (eq (car expr) '+) (nth 2 expr) (math-neg (nth 2 expr)))))
(t nil)))
(defun math-is-linear (expr &optional always)
(let ((offset nil)
(coef nil))
(if (eq (car-safe expr) '+)
(if (Math-objectp (nth 1 expr))
(setq offset (nth 1 expr)
expr (nth 2 expr))
(if (Math-objectp (nth 2 expr))
(setq offset (nth 2 expr)
expr (nth 1 expr))))
(if (eq (car-safe expr) '-)
(if (Math-objectp (nth 1 expr))
(setq offset (nth 1 expr)
expr (math-neg (nth 2 expr)))
(if (Math-objectp (nth 2 expr))
(setq offset (math-neg (nth 2 expr))
expr (nth 1 expr))))))
(setq coef (math-is-multiple expr always))
(if offset
(list offset (or (car coef) 1) (or (nth 1 coef) expr))
(if coef
(cons 0 coef)))))
(defun math-is-multiple (expr &optional always)
(or (if (eq (car-safe expr) '*)
(if (Math-objectp (nth 1 expr))
(list (nth 1 expr) (nth 2 expr)))
(if (eq (car-safe expr) '/)
(if (and (Math-objectp (nth 1 expr))
(not (math-equal-int (nth 1 expr) 1)))
(list (nth 1 expr) (math-div 1 (nth 2 expr)))
(if (Math-objectp (nth 2 expr))
(list (math-div 1 (nth 2 expr)) (nth 1 expr))
(let ((res (math-is-multiple (nth 1 expr))))
(if res
(list (car res)
(math-div (nth 2 (nth 1 expr)) (nth 2 expr)))
(setq res (math-is-multiple (nth 2 expr)))
(if res
(list (math-div 1 (car res))
(math-div (nth 1 expr)
(nth 2 (nth 2 expr)))))))))
(if (eq (car-safe expr) 'neg)
(list -1 (nth 1 expr)))))
(if (Math-objvecp expr)
(and (eq always 1)
(list expr 1))
(and always
(list 1 expr)))))
(defun calcFunc-lin (expr &optional var)
(if var
(let ((res (math-linear-in expr var t)))
(or res (math-reject-arg expr "Linear term expected"))
(list 'vec (car res) (nth 1 res) var))
(let ((res (math-is-linear expr t)))
(or res (math-reject-arg expr "Linear term expected"))
(cons 'vec res))))
(defun calcFunc-linnt (expr &optional var)
(if var
(let ((res (math-linear-in expr var)))
(or res (math-reject-arg expr "Linear term expected"))
(list 'vec (car res) (nth 1 res) var))
(let ((res (math-is-linear expr)))
(or res (math-reject-arg expr "Linear term expected"))
(cons 'vec res))))
(defun calcFunc-islin (expr &optional var)
(if (and (Math-objvecp expr) (not var))
0
(calcFunc-lin expr var)
1))
(defun calcFunc-islinnt (expr &optional var)
(if (Math-objvecp expr)
0
(calcFunc-linnt expr var)
1))
;;; Simple operations on expressions.
;;; Return number of occurrences of thing in expr, or nil if none.
(defun math-expr-contains-count (expr thing)
(cond ((equal expr thing) 1)
((Math-primp expr) nil)
(t
(let ((num 0))
(while (setq expr (cdr expr))
(setq num (+ num (or (math-expr-contains-count
(car expr) thing) 0))))
(and (> num 0)
num)))))
(defun math-expr-contains (expr thing)
(cond ((equal expr thing) 1)
((Math-primp expr) nil)
(t
(while (and (setq expr (cdr expr))
(not (math-expr-contains (car expr) thing))))
expr)))
;;; Return non-nil if any variable of thing occurs in expr.
(defun math-expr-depends (expr thing)
(if (Math-primp thing)
(and (eq (car-safe thing) 'var)
(math-expr-contains expr thing))
(while (and (setq thing (cdr thing))
(not (math-expr-depends expr (car thing)))))
thing))
;;; Substitute all occurrences of old for new in expr (non-destructive).
;; The variables math-expr-subst-old and math-expr-subst-new are local
;; for math-expr-subst, but used by math-expr-subst-rec.
(defvar math-expr-subst-old)
(defvar math-expr-subst-new)
(defun math-expr-subst (expr old new)
(let ((math-expr-subst-old old)
(math-expr-subst-new new))
(math-expr-subst-rec expr)))
(defalias 'calcFunc-subst #'math-expr-subst)
(defun math-expr-subst-rec (expr)
(cond ((equal expr math-expr-subst-old) math-expr-subst-new)
((Math-primp expr) expr)
((memq (car expr) '(calcFunc-deriv
calcFunc-tderiv))
(if (= (length expr) 2)
(if (equal (nth 1 expr) math-expr-subst-old)
(append expr (list math-expr-subst-new))
expr)
(list (car expr) (nth 1 expr)
(math-expr-subst-rec (nth 2 expr)))))
(t
(cons (car expr)
(mapcar #'math-expr-subst-rec (cdr expr))))))
;;; Various measures of the size of an expression.
(defun math-expr-weight (expr)
(if (Math-primp expr)
1
(let ((w 1))
(while (setq expr (cdr expr))
(setq w (+ w (math-expr-weight (car expr)))))
w)))
(defun math-expr-height (expr)
(if (Math-primp expr)
0
(let ((h 0))
(while (setq expr (cdr expr))
(setq h (max h (math-expr-height (car expr)))))
(1+ h))))
;;; Polynomial operations (to support the integrator and solve-for).
(defun calcFunc-collect (expr base)
(let ((p (math-is-polynomial expr base 50 t)))
(if (cdr p)
(math-build-polynomial-expr (mapcar #'math-normalize p) base)
(car p))))
;;; If expr is of the form "a + bx + cx^2 + ...", return the list (a b c ...),
;;; else return nil if not in polynomial form. If "loose" (math-is-poly-loose),
;;; coefficients may contain x, e.g., sin(x) + cos(x) x^2 is a loose polynomial in x.
;; These variables are local to math-is-polynomial, but are used by
;; math-is-poly-rec.
(defvar math-is-poly-degree)
(defvar math-is-poly-loose)
(defvar math-var)
(defvar math-poly-base-variable)
(defun math-is-polynomial (expr var &optional degree loose)
(let* ((math-poly-base-variable (if loose
(if (eq loose 'gen) var '(var XXX XXX))
math-poly-base-variable))
(math-var var)
(math-is-poly-loose loose)
(math-is-poly-degree degree)
(poly (math-is-poly-rec expr math-poly-neg-powers)))
(and (or (null degree)
(<= (length poly) (1+ degree)))
poly)))
(defun math-is-poly-rec (expr negpow)
(math-poly-simplify
(or (cond ((or (equal expr math-var)
(eq (car-safe expr) '^))
(let ((pow 1)
(expr expr))
(or (equal expr math-var)
(setq pow (nth 2 expr)
expr (nth 1 expr)))
(or (eq math-poly-mult-powers 1)
(setq pow (let ((m (math-is-multiple pow 1)))
(and (eq (car-safe (car m)) 'cplx)
(Math-zerop (nth 1 (car m)))
(setq m (list (nth 2 (car m))
(math-mul (nth 1 m)
'(var i var-i)))))
(and (if math-poly-mult-powers
(equal math-poly-mult-powers
(nth 1 m))
(setq math-poly-mult-powers (nth 1 m)))
(or (equal expr math-var)
(eq math-poly-mult-powers 1))
(car m)))))
(if (consp pow)
(progn
(setq pow (math-to-simple-fraction pow))
(and (eq (car-safe pow) 'frac)
math-poly-frac-powers
(equal expr math-var)
(setq math-poly-frac-powers
(calcFunc-lcm math-poly-frac-powers
(nth 2 pow))))))
(or (memq math-poly-frac-powers '(1 nil))
(setq pow (math-mul pow math-poly-frac-powers)))
(if (integerp pow)
(if (and (= pow 1)
(equal expr math-var))
(list 0 1)
(if (natnump pow)
(let ((p1 (if (equal expr math-var)
(list 0 1)
(math-is-poly-rec expr nil)))
(n pow)
(accum (list 1)))
(and p1
(or (null math-is-poly-degree)
(<= (* (1- (length p1)) n) math-is-poly-degree))
(progn
(while (>= n 1)
(setq accum (math-poly-mul accum p1)
n (1- n)))
accum)))
(and negpow
(math-is-poly-rec expr nil)
(setq math-poly-neg-powers
(cons (math-pow expr (- pow))
math-poly-neg-powers))
(list (list '^ expr pow))))))))
((Math-objectp expr)
(list expr))
((memq (car expr) '(+ -))
(let ((p1 (math-is-poly-rec (nth 1 expr) negpow)))
(and p1
(let ((p2 (math-is-poly-rec (nth 2 expr) negpow)))
(and p2
(math-poly-mix p1 1 p2
(if (eq (car expr) '+) 1 -1)))))))
((eq (car expr) 'neg)
(mapcar #'math-neg (math-is-poly-rec (nth 1 expr) negpow)))
((eq (car expr) '*)
(let ((p1 (math-is-poly-rec (nth 1 expr) negpow)))
(and p1
(let ((p2 (math-is-poly-rec (nth 2 expr) negpow)))
(and p2
(or (null math-is-poly-degree)
(<= (- (+ (length p1) (length p2)) 2)
math-is-poly-degree))
(math-poly-mul p1 p2))))))
((eq (car expr) '/)
(and (or (not (math-poly-depends (nth 2 expr) math-var))
(and negpow
(math-is-poly-rec (nth 2 expr) nil)
(setq math-poly-neg-powers
(cons (nth 2 expr) math-poly-neg-powers))))
(not (Math-zerop (nth 2 expr)))
(let ((p1 (math-is-poly-rec (nth 1 expr) negpow)))
(mapcar (lambda (x) (math-div x (nth 2 expr)))
p1))))
((and (eq (car expr) 'calcFunc-exp)
(equal math-var '(var e var-e)))
(math-is-poly-rec (list '^ math-var (nth 1 expr)) negpow))
((and (eq (car expr) 'calcFunc-sqrt)
math-poly-frac-powers)
(math-is-poly-rec (list '^ (nth 1 expr) '(frac 1 2)) negpow))
(t nil))
(and (or (not (math-poly-depends expr math-var))
math-is-poly-loose)
(not (eq (car expr) 'vec))
(list expr)))))
;;; Check if expr is a polynomial in var; if so, return its degree.
(defun math-polynomial-p (expr var)
(cond ((equal expr var) 1)
((Math-primp expr) 0)
((memq (car expr) '(+ -))
(let ((p1 (math-polynomial-p (nth 1 expr) var))
p2)
(and p1 (setq p2 (math-polynomial-p (nth 2 expr) var))
(max p1 p2))))
((eq (car expr) '*)
(let ((p1 (math-polynomial-p (nth 1 expr) var))
p2)
(and p1 (setq p2 (math-polynomial-p (nth 2 expr) var))
(+ p1 p2))))
((eq (car expr) 'neg)
(math-polynomial-p (nth 1 expr) var))
((and (eq (car expr) '/)
(not (math-poly-depends (nth 2 expr) var)))
(math-polynomial-p (nth 1 expr) var))
((and (eq (car expr) '^)
(natnump (nth 2 expr)))
(let ((p1 (math-polynomial-p (nth 1 expr) var)))
(and p1 (* p1 (nth 2 expr)))))
((math-poly-depends expr var) nil)
(t 0)))
(defun math-poly-depends (expr var)
(if math-poly-base-variable
(math-expr-contains expr math-poly-base-variable)
(math-expr-depends expr var)))
;; The variables math-poly-base-const-ok and math-poly-base-pred are
;; local to math-polynomial-base, but are used by math-polynomial-base-rec.
(defvar math-poly-base-const-ok)
(defvar math-poly-base-pred)
(defun math-polynomial-base (top-expr &optional pred)
"Find the variable (or sub-expression) which is the base of polynomial expr."
(let ((math-poly-base-pred
(or pred (lambda (base)
(math-polynomial-p
top-expr base)))))
(or (let ((math-poly-base-const-ok nil))
(math-polynomial-base-rec top-expr))
(let ((math-poly-base-const-ok t))
(math-polynomial-base-rec top-expr)))))
(defun math-polynomial-base-rec (mpb-expr)
(and (not (Math-objvecp mpb-expr))
(or (and (memq (car mpb-expr) '(+ - *))
(or (math-polynomial-base-rec (nth 1 mpb-expr))
(math-polynomial-base-rec (nth 2 mpb-expr))))
(and (memq (car mpb-expr) '(/ neg))
(math-polynomial-base-rec (nth 1 mpb-expr)))
(and (eq (car mpb-expr) '^)
(math-polynomial-base-rec (nth 1 mpb-expr)))
(and (eq (car mpb-expr) 'calcFunc-exp)
(math-polynomial-base-rec '(var e var-e)))
(and (or math-poly-base-const-ok (math-expr-contains-vars mpb-expr))
(funcall math-poly-base-pred mpb-expr)
mpb-expr))))
(defun math-expr-contains-vars (expr)
"Return non-nil if expr refers to any variables."
(or (eq (car-safe expr) 'var)
(and (not (Math-primp expr))
(progn
(while (and (setq expr (cdr expr))
(not (math-expr-contains-vars (car expr)))))
expr))))
(defun math-poly-simplify (p)
"Simplify a polynomial in list form by stripping off high-end zeros.
This always leaves the constant part, i.e., nil->nil and non-nil->non-nil."
(and p
(if (Math-zerop (nth (1- (length p)) p))
(let ((pp (copy-sequence p)))
(while (and (cdr pp)
(Math-zerop (nth (1- (length pp)) pp)))
(setcdr (nthcdr (- (length pp) 2) pp) nil))
pp)
p)))
;;; Compute ac*a + bc*b for polynomials in list form a, b and
;;; coefficients ac, bc. Result may be unsimplified.
(defun math-poly-mix (a ac b bc)
(and (or a b)
(cons (math-add (math-mul (or (car a) 0) ac)
(math-mul (or (car b) 0) bc))
(math-poly-mix (cdr a) ac (cdr b) bc))))
(defun math-poly-zerop (a)
(or (null a)
(and (null (cdr a)) (Math-zerop (car a)))))
(defun math-poly-mul (a b)
"Multiply two polynomials in list form."
(and a b
(math-poly-mix b (car a)
(math-poly-mul (cdr a) (cons 0 b)) 1)))
(defun math-build-polynomial-expr (p var)
"Build an expression from a polynomial list."
(if p
(if (Math-numberp var)
(math-with-extra-prec 1
(let* ((rp (reverse p))
(accum (car rp)))
(while (setq rp (cdr rp))
(setq accum (math-add (car rp) (math-mul accum var))))
accum))
(let* ((rp (reverse p))
(n (1- (length rp)))
(accum (math-mul (car rp) (math-pow var n))))
(while (setq rp (cdr rp))
(setq n (1- n))
(or (math-zerop (car rp))
(setq accum (list (if (math-looks-negp (car rp)) '- '+)
accum
(math-mul (if (math-looks-negp (car rp))
(math-neg (car rp))
(car rp))
(math-pow var n))))))
accum))
0))
(defun math-to-simple-fraction (f)
(or (and (eq (car-safe f) 'float)
(or (and (>= (nth 2 f) 0)
(math-scale-int (nth 1 f) (nth 2 f)))
(and (integerp (nth 1 f))
(> (nth 1 f) -1000)
(< (nth 1 f) 1000)
(math-make-frac (nth 1 f)
(math-scale-int 1 (- (nth 2 f)))))))
f))
(provide 'calc-alg)
;;; calc-alg.el ends here