2 * Copyright (c) 1987, 1993
3 * The Regents of the University of California. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 static char sccsid
[] = "@(#)sincos.c 8.1 (Berkeley) 6/4/93";
45 if(!finite(x
)) /* sin(NaN) and sin(INF) must be NaN */
47 x
=drem(x
,PI2
); /* reduce x into [-PI,PI] */
50 if(a
>= PI3o4
) /* ... in [3PI/4,PI] */
51 x
= copysign((a
= PI
-a
),x
);
52 else { /* ... in [PI/4,3PI/4] */
53 a
= PIo2
-a
; /* rtn. sign(x)*C(PI/2-|x|) */
57 a
= (z
>= thresh
? half
-((z
-half
)-c
) : one
-(z
-c
));
62 if (a
< small
) { /* rtn. S(x) */
66 return x
+x
*sin__S(x
*x
);
75 if(!finite(x
)) /* cos(NaN) and cos(INF) must be NaN */
77 x
=drem(x
,PI2
); /* reduce x into [-PI,PI] */
80 if (a
>= PI3o4
) { /* ... in [3PI/4,PI] */
84 else { /* ... in [PI/4,3PI/4] */
86 return a
+a
*sin__S(a
*a
); /* rtn. S(PI/2-|x|) */
91 return s
; /* rtn. s*C(a) */
96 a
= (z
>= thresh
? half
-((z
-half
)-c
) : one
-(z
-c
));