1 /* $OpenBSD: s_cexp.c,v 1.6 2013/07/03 04:46:36 espie Exp $ */ 2 /* 3 * Copyright (c) 2008 Stephen L. Moshier <steve@moshier.net> 4 * 5 * Permission to use, copy, modify, and distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 10 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 11 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 12 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 13 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 14 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 15 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18 /* cexp() 19 * 20 * Complex exponential function 21 * 22 * 23 * 24 * SYNOPSIS: 25 * 26 * double complex cexp (); 27 * double complex z, w; 28 * 29 * w = cexp (z); 30 * 31 * 32 * 33 * DESCRIPTION: 34 * 35 * Returns the exponential of the complex argument z 36 * into the complex result w. 37 * 38 * If 39 * z = x + iy, 40 * r = exp(x), 41 * 42 * then 43 * 44 * w = r cos y + i r sin y. 45 * 46 * 47 * ACCURACY: 48 * 49 * Relative error: 50 * arithmetic domain # trials peak rms 51 * DEC -10,+10 8700 3.7e-17 1.1e-17 52 * IEEE -10,+10 30000 3.0e-16 8.7e-17 53 * 54 */ 55 56 #include <complex.h> 57 #include <float.h> 58 #include <math.h> 59 60 double complex 61 cexp(double complex z) 62 { 63 double complex w; 64 double r, x, y; 65 66 x = creal (z); 67 y = cimag (z); 68 r = exp (x); 69 w = r * cos (y) + r * sin (y) * I; 70 return (w); 71 } 72 73 #if LDBL_MANT_DIG == DBL_MANT_DIG 74 __strong_alias(cexpl, cexp); 75 #endif /* LDBL_MANT_DIG == DBL_MANT_DIG */ 76