Catanh (3) Linux Manual Page

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>
", argv[0]);
        exit(EXIT_FAILURE);
    }

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

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

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

exit(EXIT_SUCCESS); }

COLOPHON

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catanh (3) Linux Manual Page