amath  1.8.5
Simple command line calculator
ccsc.c
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1 /*-
2  * Copyright (c) 2014-2018 Carsten Sonne Larsen <cs@innolan.net>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
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11  * notice, this list of conditions and the following disclaimer in the
12  * documentation and/or other materials provided with the distribution.
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28  */
29 
30 #include "prim.h"
31 
32 /**
33  * @brief Cosecant of a complex number
34  * @details
35  * Calculated as in Open Office:
36  * <pre>
37  * a+bi
38  * 2.0 * sin(a) * cosh(b)
39  * real = ------------------------------
40  * cosh(2.0 * b) - cos(2.0 * a)
41  *
42  * -2.0 * cos(a) * sinh(b)
43  * imag = ------------------------------
44  * cosh(2.0 * b) - cos(2.0 * a)
45  * </pre>
46  * https://wiki.openoffice.org/wiki/Documentation/How_Tos/Calc:_IMCSC_function
47  */
48 complex ccsc(complex z)
49 {
50  complex w;
51  double a, b;
52  double d;
53 
54  a = creal(z);
55  b = cimag(z);
56  d = cosh(2.0 * b) - cos(2.0 * a);
57 
58  if (d == 0.0)
59  {
60  w = cpack((double)INFP, (double)INFP);
61  }
62  else
63  {
64  w = cpack((2.0 * sin(a) * cosh(b) / d), (-2.0 * cos(a) * sinh(b) / d));
65  }
66 
67  return w;
68 }
double cos(double x)
Cosine function.
Definition: cos.c:87
double creal(complex z)
Real part of complex number.
Definition: prim.c:38
#define INFP
Definition: mathr.h:51
double sinh(double x)
Hyperbolic sine function.
Definition: sinh.c:77
complex cpack(double x, double y)
Pack two real numbers into a complex number.
Definition: prim.c:68
complex ccsc(complex z)
Cosecant of a complex number.
Definition: ccsc.c:48
double cimag(complex z)
Imaginary part of complex number.
Definition: prim.c:46
double cosh(double x)
Hyperbolic cosine function.
Definition: cosh.c:83
double sin(double x)
Sine function.
Definition: sin.c:86