catanh man page

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).

InterfaceAttributeValue
catanh(), catanhf(), catanhl()Thread safetyMT-Safe

Conforming to

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

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

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Referenced By

atanh(3), complex(7), ctanh(3).

catanhf(3) and catanhl(3) are aliases of catanh(3).

2015-04-19 Linux Programmer's Manual