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CATANH(3)                  Linux Programmer's Manual                 CATANH(3)

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
       The  catanh() function calculates 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.
CONFORMING TO
       C99.
EXAMPLE
       /* 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
       This  page  is  part of release 3.53 of the Linux man-pages project.  A
       description of the project, and information about reporting  bugs,  can
       be found at http://www.kernel.org/doc/man-pages/.

                                  2011-09-15                         CATANH(3)