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).

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