1*0a6a1f1dSLionel Sambuc /* $NetBSD: catanl.c,v 1.1 2014/10/10 00:48:18 christos Exp $ */
2*0a6a1f1dSLionel Sambuc
3*0a6a1f1dSLionel Sambuc /*-
4*0a6a1f1dSLionel Sambuc * Copyright (c) 2007 The NetBSD Foundation, Inc.
5*0a6a1f1dSLionel Sambuc * All rights reserved.
6*0a6a1f1dSLionel Sambuc *
7*0a6a1f1dSLionel Sambuc * This code is derived from software written by Stephen L. Moshier.
8*0a6a1f1dSLionel Sambuc * It is redistributed by the NetBSD Foundation by permission of the author.
9*0a6a1f1dSLionel Sambuc *
10*0a6a1f1dSLionel Sambuc * Redistribution and use in source and binary forms, with or without
11*0a6a1f1dSLionel Sambuc * modification, are permitted provided that the following conditions
12*0a6a1f1dSLionel Sambuc * are met:
13*0a6a1f1dSLionel Sambuc * 1. Redistributions of source code must retain the above copyright
14*0a6a1f1dSLionel Sambuc * notice, this list of conditions and the following disclaimer.
15*0a6a1f1dSLionel Sambuc * 2. Redistributions in binary form must reproduce the above copyright
16*0a6a1f1dSLionel Sambuc * notice, this list of conditions and the following disclaimer in the
17*0a6a1f1dSLionel Sambuc * documentation and/or other materials provided with the distribution.
18*0a6a1f1dSLionel Sambuc *
19*0a6a1f1dSLionel Sambuc * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20*0a6a1f1dSLionel Sambuc * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21*0a6a1f1dSLionel Sambuc * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22*0a6a1f1dSLionel Sambuc * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23*0a6a1f1dSLionel Sambuc * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24*0a6a1f1dSLionel Sambuc * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25*0a6a1f1dSLionel Sambuc * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26*0a6a1f1dSLionel Sambuc * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27*0a6a1f1dSLionel Sambuc * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28*0a6a1f1dSLionel Sambuc * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29*0a6a1f1dSLionel Sambuc * POSSIBILITY OF SUCH DAMAGE.
30*0a6a1f1dSLionel Sambuc */
31*0a6a1f1dSLionel Sambuc
32*0a6a1f1dSLionel Sambuc #include "../src/namespace.h"
33*0a6a1f1dSLionel Sambuc #include <complex.h>
34*0a6a1f1dSLionel Sambuc #include <math.h>
35*0a6a1f1dSLionel Sambuc #include <float.h>
36*0a6a1f1dSLionel Sambuc #include "cephes_subrl.h"
37*0a6a1f1dSLionel Sambuc
38*0a6a1f1dSLionel Sambuc #ifdef __weak_alias
__weak_alias(catanl,_catanl)39*0a6a1f1dSLionel Sambuc __weak_alias(catanl, _catanl)
40*0a6a1f1dSLionel Sambuc #endif
41*0a6a1f1dSLionel Sambuc
42*0a6a1f1dSLionel Sambuc #define MAXNUM LDBL_MAX
43*0a6a1f1dSLionel Sambuc
44*0a6a1f1dSLionel Sambuc long double complex
45*0a6a1f1dSLionel Sambuc catanl(long double complex z)
46*0a6a1f1dSLionel Sambuc {
47*0a6a1f1dSLionel Sambuc long double complex w;
48*0a6a1f1dSLionel Sambuc long double a, t, x, x2, y;
49*0a6a1f1dSLionel Sambuc
50*0a6a1f1dSLionel Sambuc x = creall(z);
51*0a6a1f1dSLionel Sambuc y = cimagl(z);
52*0a6a1f1dSLionel Sambuc
53*0a6a1f1dSLionel Sambuc if ((x == 0.0L) && (y > 1.0L))
54*0a6a1f1dSLionel Sambuc goto ovrf;
55*0a6a1f1dSLionel Sambuc
56*0a6a1f1dSLionel Sambuc x2 = x * x;
57*0a6a1f1dSLionel Sambuc a = 1.0L - x2 - (y * y);
58*0a6a1f1dSLionel Sambuc if (a == 0.0)
59*0a6a1f1dSLionel Sambuc goto ovrf;
60*0a6a1f1dSLionel Sambuc
61*0a6a1f1dSLionel Sambuc t = 0.5L * atan2l(2.0L * x, a);
62*0a6a1f1dSLionel Sambuc w = _redupil(t);
63*0a6a1f1dSLionel Sambuc
64*0a6a1f1dSLionel Sambuc t = y - 1.0L;
65*0a6a1f1dSLionel Sambuc a = x2 + (t * t);
66*0a6a1f1dSLionel Sambuc if (a == 0.0L)
67*0a6a1f1dSLionel Sambuc goto ovrf;
68*0a6a1f1dSLionel Sambuc
69*0a6a1f1dSLionel Sambuc t = y + 1.0L;
70*0a6a1f1dSLionel Sambuc a = (x2 + (t * t))/a;
71*0a6a1f1dSLionel Sambuc w = w + (0.25L * logl(a)) * I;
72*0a6a1f1dSLionel Sambuc return w;
73*0a6a1f1dSLionel Sambuc
74*0a6a1f1dSLionel Sambuc ovrf:
75*0a6a1f1dSLionel Sambuc #if 0
76*0a6a1f1dSLionel Sambuc mtherr ("catanl", OVERFLOW);
77*0a6a1f1dSLionel Sambuc #endif
78*0a6a1f1dSLionel Sambuc w = MAXNUM + MAXNUM * I;
79*0a6a1f1dSLionel Sambuc return w;
80*0a6a1f1dSLionel Sambuc }
81