1 /* $NetBSD: cephes_subr.c,v 1.1 2007/08/20 16:01:33 drochner Exp $ */
4 * Copyright (c) 2007 The NetBSD Foundation, Inc.
7 * This code is derived from software written by Stephen L. Moshier.
8 * It is redistributed by the NetBSD Foundation by permission of the author.
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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35 #include "cephes_subr.h"
37 /* calculate cosh and sinh */
40 _cchsh(double x, double *c, double *s)
56 /* Program to subtract nearest integer multiple of PI */
58 /* extended precision value of PI: */
59 static const double DP1 = 3.14159265160560607910E0;
60 static const double DP2 = 1.98418714791870343106E-9;
61 static const double DP3 = 1.14423774522196636802E-17;
62 #define MACHEP 1.1e-16
76 i = t; /* the multiple */
78 t = ((x - t * DP1) - t * DP2) - t * DP3;
82 /* Taylor series expansion for cosh(2y) - cos(2x) */
85 _ctans(double complex z)
87 double f, x, x2, y, y2, rn, t;
90 x = fabs(2.0 * creal(z));
91 y = fabs(2.0 * cimag(z));
122 } while (fabs(t/d) > MACHEP);