1 /* $OpenBSD: s_cacoshl.c,v 1.1 2011/07/08 19:25:31 martynas Exp $ */ 2 3 /* 4 * Copyright (c) 2008 Stephen L. Moshier <steve@moshier.net> 5 * 6 * Permission to use, copy, modify, and distribute this software for any 7 * purpose with or without fee is hereby granted, provided that the above 8 * copyright notice and this permission notice appear in all copies. 9 * 10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 17 */ 18 19 /* cacoshl 20 * 21 * Complex inverse hyperbolic cosine 22 * 23 * 24 * 25 * SYNOPSIS: 26 * 27 * long double complex cacoshl(); 28 * long double complex z, w; 29 * 30 * w = cacoshl (z); 31 * 32 * 33 * 34 * DESCRIPTION: 35 * 36 * acosh z = i acos z . 37 * 38 * ACCURACY: 39 * 40 * Relative error: 41 * arithmetic domain # trials peak rms 42 * IEEE -10,+10 30000 1.6e-14 2.1e-15 43 * 44 */ 45 46 #include <complex.h> 47 #include <math.h> 48 49 long double complex 50 cacoshl(long double complex z) 51 { 52 long double complex w; 53 long double rx, ry; 54 55 w = cacosl (z); 56 rx = creall (w); 57 ry = cimagl (w); 58 if (isnan(rx) && isnan(ry)) 59 return (CMPLXL(ry, rx)); 60 if (isnan(rx)) 61 return (CMPLXL(fabsl(ry), rx)); 62 if (isnan(ry)) 63 return (CMPLXL(ry, ry)); 64 return (CMPLXL(fabsl(ry), copysignl(rx, cimagl(z)))); 65 } 66