NAME
atand(), atandf(), atandl(), atandw(), atandq() — degree-valued arctangent functions
SYNOPSIS
#include <math.h>
double atand(double x);
float atandf(float x);
IA-64 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.
IA-64 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 IA-64 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.
STANDARDS CONFORMANCE
These functions are not apecified by any standard.
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