CATANH(3) Library Functions Manual CATANH(3)

catanh catanhf catanhl — complex arc hyperbolic tangent functions

#include <complex.h>

double complex catanh(double complex z);
float complex catanhf(float complex z);
long double complex catanhl(long double complex z);

The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of POSIX.1-2024 defers to the ISO C standard.

These functions shall compute the complex arc hyperbolic tangent of z, with branch cuts outside the interval [-1, +1] along the real axis.

These functions shall return the complex arc hyperbolic tangent value, in the range of a strip mathematically unbounded along the real axis and in the interval [- i ℼ/2, + i ℼ/2] along the imaginary axis.

catanh ( conj ( z)), catanhf ( conjf ( z)), and catanhl ( conjl ( z)) shall return exactly the same value as conj ( catanh ( z)), conjf ( catanhf ( z)), and conjl ( catanhl ( z)), respectively, and catanh ( -z), catanhf ( -z), and catanhl ( -z) shall return exactly the same value as ( z), -catanhf ( z), and -catanhl ( z), respectively, including for the special values of z below.

If z is +0 + i 0, +0 + i 0 shall be returned.

If z is +0 + i NaN, +0 + i NaN shall be returned.

If z is +1 + i 0, +Inf + i 0 shall be returned and the divide-by-zero floating-point exception shall be raised.

If z is x + i Inf where x is positive-signed and finite, +0 + i ℼ/2 shall be returned.

If z is x + i NaN where x is non-zero and finite, NaN + i NaN shall be returned and the invalid floating-point exception may be raised.

If z is +Inf + iy where y is positive-signed and finite, +0 + i ℼ/2 shall be returned.

If z is +Inf + i Inf, +0 + i ℼ/2 shall be returned.

If z is +Inf + i NaN, +0 + i NaN shall be returned.

If z is NaN + iy where y is finite, NaN + i NaN shall be returned and the invalid floating-point exception may be raised.

If z is NaN + i Inf, ±0 + i ℼ/2 shall be returned; the sign of the real part of the result is unspecified.

If z is NaN + i NaN, NaN + i NaN shall be returned.

No errors are defined.

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ctanh(3)

XBD <complex.h>

First released in Issue 6. Derived from the ISO/IEC 9899:1999 (“ISO C99”) standard.

Austin Group Defect 1302 is applied, aligning these functions with the ISO/IEC 9899:2018 standard.

June 14, 2024 posix.fail