HP-UX Reference (11i v2 03/08) - 3 Library Functions A-M (vol 6)

c
catanh(3M) catanh(3M)
(Itanium(R)-based System Only)
NAME
catanh( ), catanhf( ), catanhl( ), catanhw( ), catanhq() - complex arc hyperbolic tangent functions
SYNOPSIS
#include <complex.h>
double complex catanh(double complex z);
float complex catanhf(float complex z);
long double complex catanhl(long double complex z);
extended complex catanhw(extended complex z);
quad complex catanhq(quad complex z);
DESCRIPTION
These functions are available only for Itanium-based systems.
catanh() returns the complex arc hyperbolic tangent of z, in the range of a strip mathematically
unbounded along the real axis and in the interval [-iπ/2,iπ/2] along the imaginary axis. Branch cuts are
outside the interval [-1,+1] along the real axis.
catanhf() is a float complex version of catanh(); it takes a float complex argument and
returns a float complex result.
catanhl() is a long double complex version of catanh(); it takes a long double complex
argument and returns a long double complex result.
catanhw() is an extended complex version of catanh(); it takes an extended complex argu-
ment and returns an extended complex result.
catanhq() is equivalent to catanhl() on HP-UX systems.
USAGE
To use these functions, compile with the default
-Ae option. To use catanhw() or
catanhq(), com-
pile with the
-fpwidetypes option. Make sure your program includes <complex.h>. Link in the
math library by specifying -lm on the compiler or linker command line.
RETURN VALUE
catanh(conj(z)) = conj(catanh(z)) and catanh is odd.
catanh(+0+i0) returns +0+i0.
catanh(+0+iNaN) returns +0+iNaN.
catanh(+1+i0) returns +Inf+i0 and raises the divide-by-zero floating-point exception.
catanh(x+iInf) returns +0+iπ/2, for finite positive-signed x.
catanh(x+iNaN) returns NaN+iNaN and optionally raises the invalid floating-point exception, for
nonzero finite x.
catanh(+Inf+iy) returns +0+iπ/2, for finite positive-signed y.
catanh(+Inf+iInf) returns +0+iπ/2.
catanh(+Inf+iNaN) returns +0+iNaN.
catanh(NaN+iy) returns NaN+iNaN and optionally raises the invalid floating-point exception, for
finite y.
catanh(NaN+iInf) returns ±0+iπ/2 (where the sign of the real part of the result is unspecified).
catanh(NaN+iNaN) returns NaN+iNaN.
ERRORS
No errors are defined.
SEE ALSO
atanh(3M), ctanh(3M), complex(5).
HP-UX 11i Version 2: August 2003 − 1 − Hewlett-Packard Company Section 3−−77