99 lines
3.0 KiB
C
99 lines
3.0 KiB
C
/*
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* Copyright (c) 1987, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#ifndef lint
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static char sccsid[] = "@(#)sincos.c 8.1 (Berkeley) 6/4/93";
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#endif /* not lint */
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#include "trig.h"
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double
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sin(x)
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double x;
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{
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double a,c,z;
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if(!finite(x)) /* sin(NaN) and sin(INF) must be NaN */
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return x-x;
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x=drem(x,PI2); /* reduce x into [-PI,PI] */
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a=copysign(x,one);
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if (a >= PIo4) {
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if(a >= PI3o4) /* ... in [3PI/4,PI] */
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x = copysign((a = PI-a),x);
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else { /* ... in [PI/4,3PI/4] */
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a = PIo2-a; /* rtn. sign(x)*C(PI/2-|x|) */
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z = a*a;
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c = cos__C(z);
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z *= half;
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a = (z >= thresh ? half-((z-half)-c) : one-(z-c));
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return copysign(a,x);
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}
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}
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if (a < small) { /* rtn. S(x) */
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big+a;
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return x;
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}
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return x+x*sin__S(x*x);
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}
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double
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cos(x)
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double x;
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{
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double a,c,z,s = 1.0;
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if(!finite(x)) /* cos(NaN) and cos(INF) must be NaN */
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return x-x;
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x=drem(x,PI2); /* reduce x into [-PI,PI] */
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a=copysign(x,one);
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if (a >= PIo4) {
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if (a >= PI3o4) { /* ... in [3PI/4,PI] */
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a = PI-a;
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s = negone;
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}
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else { /* ... in [PI/4,3PI/4] */
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a = PIo2-a;
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return a+a*sin__S(a*a); /* rtn. S(PI/2-|x|) */
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}
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}
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if (a < small) {
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big+a;
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return s; /* rtn. s*C(a) */
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}
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z = a*a;
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c = cos__C(z);
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z *= half;
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a = (z >= thresh ? half-((z-half)-c) : one-(z-c));
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return copysign(a,s);
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}
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