| [78] | 1 | ;;; -*- Mode: Lisp; Package: Maxima; Syntax: Common-Lisp; Base: 10 -*-
|
|---|
| 2 | ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|---|
| 3 | ;;;
|
|---|
| 4 | ;;; Copyright (C) 1999, 2002, 2009, 2015 Marek Rychlik <rychlik@u.arizona.edu>
|
|---|
| 5 | ;;;
|
|---|
| 6 | ;;; This program is free software; you can redistribute it and/or modify
|
|---|
| 7 | ;;; it under the terms of the GNU General Public License as published by
|
|---|
| 8 | ;;; the Free Software Foundation; either version 2 of the License, or
|
|---|
| 9 | ;;; (at your option) any later version.
|
|---|
| 10 | ;;;
|
|---|
| 11 | ;;; This program is distributed in the hope that it will be useful,
|
|---|
| 12 | ;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|---|
| 13 | ;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|---|
| 14 | ;;; GNU General Public License for more details.
|
|---|
| 15 | ;;;
|
|---|
| 16 | ;;; You should have received a copy of the GNU General Public License
|
|---|
| 17 | ;;; along with this program; if not, write to the Free Software
|
|---|
| 18 | ;;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
|
|---|
| 19 | ;;;
|
|---|
| 20 | ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
|
|---|
| 21 |
|
|---|
| [397] | 22 | (defpackage "TERM"
|
|---|
| [410] | 23 | (:use :cl :monomial :ring)
|
|---|
| [435] | 24 | (:export "TERM"
|
|---|
| 25 | "TERM-MONOM"
|
|---|
| 26 | "TERM-COEFF"
|
|---|
| [402] | 27 | "MAKE-TERM"
|
|---|
| [403] | 28 | "MAKE-TERM-VARIABLE"
|
|---|
| 29 | "TERM-MUL"
|
|---|
| [402] | 30 | "TERM-SUGAR"))
|
|---|
| [78] | 31 |
|
|---|
| [142] | 32 |
|
|---|
| [420] | 33 | (in-package :term)
|
|---|
| 34 |
|
|---|
| [51] | 35 | (defun make-term-variable (ring nvars pos
|
|---|
| 36 | &optional
|
|---|
| 37 | (power 1)
|
|---|
| 38 | (coeff (funcall (ring-unit ring)))
|
|---|
| 39 | &aux
|
|---|
| 40 | (monom (make-monom nvars :initial-element 0)))
|
|---|
| [400] | 41 | "Construct a term in the polynomial ring RING[X[0],X[1],X[2],...X[NVARS-1]]
|
|---|
| [399] | 42 | over the ring RING which represents a single variable. It assumes
|
|---|
| 43 | number of variables NVARS and the variable is at position
|
|---|
| 44 | POS. Optionally, the variable may appear raised to power POWER.
|
|---|
| 45 | Optionally, the term may appear with an arbitrary coefficient, which
|
|---|
| 46 | defaults to the unit of the RING."
|
|---|
| [51] | 47 | (declare (fixnum nvars pos power))
|
|---|
| 48 | (incf (monom-elt monom pos) power)
|
|---|
| 49 | (make-term monom coeff))
|
|---|
| 50 |
|
|---|
| 51 | (defstruct (term
|
|---|
| 52 | (:constructor make-term (monom coeff))
|
|---|
| 53 | ;;(:constructor make-term-variable)
|
|---|
| 54 | ;;(:type list)
|
|---|
| 55 | )
|
|---|
| 56 | (monom (make-monom 0) :type monom)
|
|---|
| 57 | (coeff nil))
|
|---|
| 58 |
|
|---|
| [377] | 59 | (defun term-mul (ring term1 term2)
|
|---|
| 60 | "Returns the product of the terms TERM1 and TERM2,
|
|---|
| 61 | or NIL when the product is 0. This definition takes care of divisors of 0
|
|---|
| 62 | in the coefficient ring."
|
|---|
| 63 | (let ((c (funcall (ring-mul ring) (term-coeff term1) (term-coeff term2))))
|
|---|
| 64 | (unless (funcall (ring-zerop ring) c)
|
|---|
| [378] | 65 | (make-term (monom-mul (term-monom term1) (term-monom term2)) c))))
|
|---|
| [403] | 66 |
|
|---|
| 67 | (defun term-sugar (term)
|
|---|
| 68 | (monom-sugar (term-monom term)))
|
|---|
