1*05a0b428SJohn Marino /* $OpenBSD: s_csinf.c,v 1.2 2010/07/18 18:42:26 guenther Exp $ */ 2*05a0b428SJohn Marino /* 3*05a0b428SJohn Marino * Copyright (c) 2008 Stephen L. Moshier <steve@moshier.net> 4*05a0b428SJohn Marino * 5*05a0b428SJohn Marino * Permission to use, copy, modify, and distribute this software for any 6*05a0b428SJohn Marino * purpose with or without fee is hereby granted, provided that the above 7*05a0b428SJohn Marino * copyright notice and this permission notice appear in all copies. 8*05a0b428SJohn Marino * 9*05a0b428SJohn Marino * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10*05a0b428SJohn Marino * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11*05a0b428SJohn Marino * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12*05a0b428SJohn Marino * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13*05a0b428SJohn Marino * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14*05a0b428SJohn Marino * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15*05a0b428SJohn Marino * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16*05a0b428SJohn Marino */ 17*05a0b428SJohn Marino 18*05a0b428SJohn Marino /* csinf() 19*05a0b428SJohn Marino * 20*05a0b428SJohn Marino * Complex circular sine 21*05a0b428SJohn Marino * 22*05a0b428SJohn Marino * 23*05a0b428SJohn Marino * 24*05a0b428SJohn Marino * SYNOPSIS: 25*05a0b428SJohn Marino * 26*05a0b428SJohn Marino * void csinf(); 27*05a0b428SJohn Marino * cmplxf z, w; 28*05a0b428SJohn Marino * 29*05a0b428SJohn Marino * csinf( &z, &w ); 30*05a0b428SJohn Marino * 31*05a0b428SJohn Marino * 32*05a0b428SJohn Marino * 33*05a0b428SJohn Marino * DESCRIPTION: 34*05a0b428SJohn Marino * 35*05a0b428SJohn Marino * If 36*05a0b428SJohn Marino * z = x + iy, 37*05a0b428SJohn Marino * 38*05a0b428SJohn Marino * then 39*05a0b428SJohn Marino * 40*05a0b428SJohn Marino * w = sin x cosh y + i cos x sinh y. 41*05a0b428SJohn Marino * 42*05a0b428SJohn Marino * 43*05a0b428SJohn Marino * 44*05a0b428SJohn Marino * ACCURACY: 45*05a0b428SJohn Marino * 46*05a0b428SJohn Marino * Relative error: 47*05a0b428SJohn Marino * arithmetic domain # trials peak rms 48*05a0b428SJohn Marino * IEEE -10,+10 30000 1.9e-7 5.5e-8 49*05a0b428SJohn Marino * 50*05a0b428SJohn Marino */ 51*05a0b428SJohn Marino 52*05a0b428SJohn Marino #include <complex.h> 53*05a0b428SJohn Marino #include <math.h> 54*05a0b428SJohn Marino 55*05a0b428SJohn Marino /* calculate cosh and sinh */ 56*05a0b428SJohn Marino 57*05a0b428SJohn Marino static void 58*05a0b428SJohn Marino cchshf(float xx, float *c, float *s) 59*05a0b428SJohn Marino { 60*05a0b428SJohn Marino float x, e, ei; 61*05a0b428SJohn Marino 62*05a0b428SJohn Marino x = xx; 63*05a0b428SJohn Marino if(fabsf(x) <= 0.5f) { 64*05a0b428SJohn Marino *c = coshf(x); 65*05a0b428SJohn Marino *s = sinhf(x); 66*05a0b428SJohn Marino } 67*05a0b428SJohn Marino else { 68*05a0b428SJohn Marino e = expf(x); 69*05a0b428SJohn Marino ei = 0.5f/e; 70*05a0b428SJohn Marino e = 0.5f * e; 71*05a0b428SJohn Marino *s = e - ei; 72*05a0b428SJohn Marino *c = e + ei; 73*05a0b428SJohn Marino } 74*05a0b428SJohn Marino } 75*05a0b428SJohn Marino 76*05a0b428SJohn Marino float complex 77*05a0b428SJohn Marino csinf(float complex z) 78*05a0b428SJohn Marino { 79*05a0b428SJohn Marino float complex w; 80*05a0b428SJohn Marino float ch, sh; 81*05a0b428SJohn Marino 82*05a0b428SJohn Marino cchshf(cimagf(z), &ch, &sh); 83*05a0b428SJohn Marino w = sinf(crealf(z)) * ch + (cosf(crealf(z)) * sh) * I; 84*05a0b428SJohn Marino return (w); 85*05a0b428SJohn Marino } 86