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HP-UX Reference > C


HP Integrity Server Only
HP-UX 11i Version 3: February 2007

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catanh(), catanhf(), catanhl(), catanhw(), catanhq() — 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);

extended complex catanhw(extended complex z);

quad complex catanhq(quad complex z);


These functions are available only for Integrity servers.

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 argument and returns an extended complex result.

catanhq() is equivalent to catanhl() on HP-UX systems.


To use these functions, compile with the default -Ae option. To use catanhw() or catanhq(), compile 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.


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.


No errors are defined.


catanh(), catanhf(), catanh() : ISO/IEC C99 (including Annex G, ``IEC 60559-compatible complex arithmetic'')

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