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

atand(3M) atand(3M)

NAME

atand( ), atandf( ), atandl( ), atandw( ), atandq( ) - degree-valued arctangent functions

SYNOPSIS

#include <math.h>

double atand(double x);

float atandf(float x);

Itanium(R)-based System Only

long double atandl(long double x);

extended atandw(extended x);

quad atandq(quad x);

DESCRIPTION

atand() returns the degree-valued arctangent of x, in the range −90 to 90.

atandf() is a float version of atand(); it takes a

float argument and returns a float result.

Itanium-based System Only

atandl() is a long double version of atand(); it takes a long double argument and returns a

long double result.

atandw() is an extended version of atand(); it takes an extended argument and returns an

extended result.

atandq() is equivalent to atandl() on HP-UX systems.

USAGE

To use these functions, compile either with the default

-Ae option or with the -Aa

and

-D_HPUX_SOURCE options.

To use (for Itanium-based systems)

atandw() or atandq(), compile also with the -fpwidetypes

option.

To use any of these functions, make sure your program includes

<math.h>, and link in the math library

by specifying -lm on the compiler or linker command line.

For more information, see the HP-UX Floating-Point Guide.

RETURN VALUE

atand(±0) returns ±0.

If x is ±INFINITY,

atand() returns ±90 respectively.

If x is NaN,

atand() returns NaN.

ERRORS

No errors are deﬁned.