man3/catanh.3

   1 .\" Copyright 2002 Walter Harms (walter.harms@informatik.uni-oldenburg.de)
   2 .\" and Copyright (C) 2011 Michael Kerrisk <mtk.manpages@gamil.com>
   3 .\"
   4 .\" %%%LICENSE_START(GPL_NOVERSION_ONELINE)
   5 .\" Distributed under GPL
   6 .\" %%%LICENSE_END
   7 .\"
   8 .TH CATANH 3 2015-03-02 "" "Linux Programmer's Manual"
   9 .SH NAME
  10 catanh, catanhf, catanhl \- complex arc tangents hyperbolic
  11 .SH SYNOPSIS
  12 .B #include <complex.h>
  13 .sp
  14 .BI "double complex catanh(double complex " z );
  15 .br
  16 .BI "float complex catanhf(float complex " z );
  17 .br
  18 .BI "long double complex catanhl(long double complex " z );
  19 .sp
  20 Link with \fI\-lm\fP.
  21 .SH DESCRIPTION
  22 The
  23 .BR catanh ()
  24 function calculates the complex arc hyperbolic tangent of
  25 .IR z .
  26 If \fIy\ =\ catanh(z)\fP, then \fIz\ =\ ctanh(y)\fP.
  27 The imaginary part of
  28 .I y
  29 is chosen in the interval [\-pi/2,pi/2].
  30 .LP
  31 One has:
  32 .nf
  33
  34     catanh(z) = 0.5 * (clog(1 + z) \- clog(1 \- z))
  35 .fi
  36 .SH VERSIONS
  37 These functions first appeared in glibc in version 2.1.
  38 .SH ATTRIBUTES
  39 For an explanation of the terms used in this section, see
  40 .BR attributes (7).
  41 .TS
  42 allbox;
  43 lbw30 lb lb
  44 l l l.
  45 Interface       Attribute       Value
  46 T{
  47 .BR catanh (),
  48 .BR catanhf (),
  49 .BR catanhl ()
  50 T}      Thread safety   MT-Safe
  51 .TE
  52 .SH CONFORMING TO
  53 C99, POSIX.1-2001, POSIX.1-2008.
  54 .SH EXAMPLE
  55 .nf
  56 /* Link with "\-lm" */
  57
  58 #include <complex.h>
  59 #include <stdlib.h>
  60 #include <unistd.h>
  61 #include <stdio.h>
  62
  63 int
  64 main(int argc, char *argv[])
  65 {
  66     double complex z, c, f;
  67
  68     if (argc != 3) {
  69         fprintf(stderr, "Usage: %s <real> <imag>\\n", argv[0]);
  70         exit(EXIT_FAILURE);
  71     }
  72
  73     z = atof(argv[1]) + atof(argv[2]) * I;
  74
  75     c = catanh(z);
  76     printf("catanh() = %6.3f %6.3f*i\\n", creal(c), cimag(c));
  77
  78     f = 0.5 * (clog(1 + z) \- clog(1 \- z));
  79     printf("formula  = %6.3f %6.3f*i\\n", creal(f2), cimag(f2));
  80
  81     exit(EXIT_SUCCESS);
  82 }
  83 .fi
  84 .SH SEE ALSO
  85 .BR atanh (3),
  86 .BR cabs (3),
  87 .BR cimag (3),
  88 .BR ctanh (3),
  89 .BR complex (7)