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CATANH(3) Library Functions Manual CATANH(3)

NAME

catanh, catanhf, catanhl - complex arc tangents hyperbolic

LIBRARY

Math library (libm, -lm)

SYNOPSIS

#include <complex.h>
double complex catanh(double complex z);
float complex catanhf(float complex z);
long double complex catanhl(long double complex z);

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

STANDARDS

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

EXAMPLES

/* Link with "-lm" */
#include <complex.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.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(f), cimag(f));
exit(EXIT_SUCCESS); }

SEE ALSO

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

2022-10-09 Linux man-pages 6.01