Manpages - catanh.3

Table of Contents

NAME

catanh, catanhf, catanhl - complex arc tangents hyperbolic

SYNOPSIS

  #include <complex.h>

  double complex catanh(double complex z);
  float complex catanhf(float complex z);
  long double complex catanhl(long double complex z);

  Link with -lm.

DESCRIPTION

These functions calculate the complex arc hyperbolic tangent of z. If y = catanh(z), then z = ctanh(y). The imaginary part of y is chosen in the interval [-pi/2,pi/2].

One has:

      catanh(z) = 0.5 * (clog(1 + z) - clog(1 - z))

VERSIONS

These functions first appeared in glibc in version 2.1.

ATTRIBUTES

For an explanation of the terms used in this section, see *attributes*(7).

Interface Attribute Value
*catanh*(), *catanhf*(), *catanhl*() Thread safety MT-Safe

CONFORMING TO

C99, POSIX.1-2001, POSIX.1-2008.

EXAMPLES

  /* Link with "-lm" */

  #include <complex.h>
  #include <stdlib.h>
  #include <unistd.h>
  #include <stdio.h>

  int
  main(int argc, char *argv[])
  {
      double complex z, c, f;

      if (argc != 3) {
          fprintf(stderr, "Usage: %s <real> <imag>\n", argv[0]);
          exit(EXIT_FAILURE);
      }

      z = atof(argv[1]) + atof(argv[2]) * I;

      c = catanh(z);
      printf("catanh() = %6.3f %6.3f*i\n", creal(c), cimag(c));

      f = 0.5 * (clog(1 + z) - clog(1 - z));
      printf("formula  = %6.3f %6.3f*i\n", creal(f2), cimag(f2));

      exit(EXIT_SUCCESS);
  }

SEE ALSO

*atanh*(3), *cabs*(3), *cimag*(3), *ctanh*(3), *complex*(7)

COLOPHON

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Author: dt

Created: 2022-02-20 Sun 14:53