105a0b428SJohn Marino /* $OpenBSD: s_cacoshf.c,v 1.1 2008/09/07 20:36:09 martynas Exp $ */
205a0b428SJohn Marino /*
305a0b428SJohn Marino * Copyright (c) 2008 Stephen L. Moshier <steve@moshier.net>
405a0b428SJohn Marino *
505a0b428SJohn Marino * Permission to use, copy, modify, and distribute this software for any
605a0b428SJohn Marino * purpose with or without fee is hereby granted, provided that the above
705a0b428SJohn Marino * copyright notice and this permission notice appear in all copies.
805a0b428SJohn Marino *
905a0b428SJohn Marino * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
1005a0b428SJohn Marino * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
1105a0b428SJohn Marino * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
1205a0b428SJohn Marino * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
1305a0b428SJohn Marino * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
1405a0b428SJohn Marino * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
1505a0b428SJohn Marino * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
1605a0b428SJohn Marino */
1705a0b428SJohn Marino
1805a0b428SJohn Marino /* cacoshf
1905a0b428SJohn Marino *
2005a0b428SJohn Marino * Complex inverse hyperbolic cosine
2105a0b428SJohn Marino *
2205a0b428SJohn Marino *
2305a0b428SJohn Marino *
2405a0b428SJohn Marino * SYNOPSIS:
2505a0b428SJohn Marino *
2605a0b428SJohn Marino * float complex cacoshf();
2705a0b428SJohn Marino * float complex z, w;
2805a0b428SJohn Marino *
2905a0b428SJohn Marino * w = cacoshf (z);
3005a0b428SJohn Marino *
3105a0b428SJohn Marino *
3205a0b428SJohn Marino *
3305a0b428SJohn Marino * DESCRIPTION:
3405a0b428SJohn Marino *
3505a0b428SJohn Marino * acosh z = i acos z .
3605a0b428SJohn Marino *
3705a0b428SJohn Marino * ACCURACY:
3805a0b428SJohn Marino *
3905a0b428SJohn Marino * Relative error:
4005a0b428SJohn Marino * arithmetic domain # trials peak rms
4105a0b428SJohn Marino * IEEE -10,+10 30000 1.6e-14 2.1e-15
4205a0b428SJohn Marino *
4305a0b428SJohn Marino */
4405a0b428SJohn Marino
4505a0b428SJohn Marino #include <complex.h>
4605a0b428SJohn Marino #include <math.h>
4705a0b428SJohn Marino
4805a0b428SJohn Marino float complex
cacoshf(float complex z)4905a0b428SJohn Marino cacoshf(float complex z)
5005a0b428SJohn Marino {
5105a0b428SJohn Marino float complex w;
52*9a1d0688SJohn Marino float rx, ry;
5305a0b428SJohn Marino
54*9a1d0688SJohn Marino w = cacosf (z);
55*9a1d0688SJohn Marino rx = crealf (w);
56*9a1d0688SJohn Marino ry = cimagf (w);
57*9a1d0688SJohn Marino if (isnan(rx) && isnan(ry))
58*9a1d0688SJohn Marino return (CMPLXF(ry, rx));
59*9a1d0688SJohn Marino if (isnan(rx))
60*9a1d0688SJohn Marino return (CMPLXF(fabsf(ry), rx));
61*9a1d0688SJohn Marino if (isnan(ry))
62*9a1d0688SJohn Marino return (CMPLXF(ry, ry));
63*9a1d0688SJohn Marino return (CMPLXF(fabsf(ry), copysignf(rx, cimagf(z))));
6405a0b428SJohn Marino }
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