1 | ;;; -*- Mode: Lisp -*-
|
---|
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 |
|
---|
22 | (defpackage "TERM"
|
---|
23 | (:use :cl :monom :ring)
|
---|
24 | (:export "TERM" "MAKE-TERM-VARIABLE"))
|
---|
25 |
|
---|
26 | (in-package :term)
|
---|
27 |
|
---|
28 | (proclaim '(optimize (speed 3) (space 0) (safety 0) (debug 0)))
|
---|
29 |
|
---|
30 | (defclass term (monom)
|
---|
31 | ((coeff :initarg :coeff :accessor r-coeff))
|
---|
32 | (:default-initargs :dimension nil :exponents nil :coeff nil))
|
---|
33 |
|
---|
34 | (defmethod print-object ((self term) stream)
|
---|
35 | (format stream "#<TERM DIMENSION=~A EXPONENTS=~A COEFF=~A>"
|
---|
36 | (r-dimension self)
|
---|
37 | (r-exponents self)
|
---|
38 | (r-coeff self)))
|
---|
39 |
|
---|
40 | (defmethod shared-initialize ((self term) slot-names
|
---|
41 | &rest
|
---|
42 | initargs
|
---|
43 | &key
|
---|
44 | coeff
|
---|
45 | &allow-other-keys)
|
---|
46 | (declare (ignore initargs))
|
---|
47 | (if (eq slot-names t) (setf slot-names '(coeff)))
|
---|
48 | (dolist (slot-name slot-names)
|
---|
49 | (case slot-name
|
---|
50 | (coeff
|
---|
51 | (setf (slot-value self 'coeff) coeff)))))
|
---|
52 |
|
---|
53 | (defmethod update-instance-for-different-class :after ((old monom)
|
---|
54 | (new term)
|
---|
55 | &key)
|
---|
56 | (setf (slot-value new 'coeff) (r-coeff old)))
|
---|
57 |
|
---|
58 |
|
---|
59 | #|
|
---|
60 | (defun make-term-variable (nvars pos
|
---|
61 | &optional
|
---|
62 | (power 1)
|
---|
63 | (coeff 1))
|
---|
64 | "Construct a term in the polynomial ring RING[X[0],X[1],X[2],...X[NVARS-1]]
|
---|
65 | over the ring RING which represents a single variable. It assumes
|
---|
66 | number of variables NVARS and the variable is at position
|
---|
67 | POS. Optionally, the variable may appear raised to power POWER.
|
---|
68 | Optionally, the term may appear with an arbitrary coefficient, which
|
---|
69 | defaults to the unit of the RING."
|
---|
70 | (declare (type fixnum nvars pos))
|
---|
71 | (make-term :monom (make-monom-variable nvars pos power)
|
---|
72 | :coeff coeff))
|
---|
73 |
|
---|
74 | |#
|
---|
75 |
|
---|
76 | (defmethod r* :around ((term1 term) (term2 term))
|
---|
77 | "Returns the product of the terms TERM1 and TERM2,
|
---|
78 | or NIL when the product is 0. This definition takes care of divisors of 0
|
---|
79 | in the coefficient ring."
|
---|
80 | (let ((result (change-class (call-next-method) 'term)))
|
---|
81 | (setf (r-coeff result) (r* (r-coeff term1) (r-coeff term2)))
|
---|
82 | result))
|
---|
83 |
|
---|
84 | (defmethod r* :around ((term1 term) (monom2 monom))
|
---|
85 | (call-next-method term1 (change-class monom2 'term)))
|
---|
86 |
|
---|
87 | (defmethod r* :around ((monom1 monom) (term2 term))
|
---|
88 | (call-next-method (change-class monom1 'term) term2))
|
---|
89 |
|
---|
90 | #|
|
---|
91 |
|
---|
92 | (defun term->cons (term)
|
---|
93 | "A human-readable representation of a term as a cons (MONOM . COEFF)."
|
---|
94 | (declare (type term term))
|
---|
95 | (cons (monom->list (term-monom term)) (term-coeff term)))
|
---|
96 |
|
---|
97 | |#
|
---|