NAME

ctanh, ctanhf, ctanhl — complex hyperbolic tangent functions

SYNOPSIS

#include <complex.h>

double complex ctanh(double complex z);
float complex ctanhf(float complex z);
long double complex ctanhl(long double complex z);


DESCRIPTION

^[CX] 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 hyperbolic tangent of z.

RETURN VALUE

These functions shall return the complex hyperbolic tangent value.

^[MXC] ctanh(conj(z)), ctanhf(conjf(z)), and ctanhl(conjl(z)) shall return exactly the same value as conj(ctanh(z)), conjf(ctanhf(z)), and conjl(ctanhl(z)), respectively, and ctanh(-z), ctanhf(-z), and ctanhl(-z) shall return exactly the same value as -ctanh(z), -ctanhf(z), and -ctanhl(z), respectively, including for the special values of z below.

If z is +0 + i0, +0 + i0 shall be returned.

If z is 0 + iInf, 0 + iNaN shall be returned and the invalid floating-point exception shall be raised.

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

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

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

If z is +Inf + iy where y is positive-signed and finite, 1 + i0 sin(2y) shall be returned.

If z is +Inf + iInf, 1 ± i0 shall be returned; the sign of the imaginary part of the result is unspecified.

If z is +Inf + iNaN, 1 ± i0 shall be returned; the sign of the imaginary part of the result is unspecified.

If z is NaN + i0, NaN + i0 shall be returned.

If z is NaN + iy where y is any non-zero number, NaN + iNaN shall be returned and the invalid floating-point exception may be raised.

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

ERRORS

No errors are defined.

EXAMPLES

None.

APPLICATION USAGE

None.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

catanh

XBD <complex.h>

CHANGE HISTORY

First released in Issue 6. Derived from the ISO/IEC 9899:1999 standard.

Issue 8

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