ATAN2DEG 3CW "09 March 2006" "mathcw-1.00"

Table of contents


NAME

atan2degf, atan2deg, atan2degl, atan2degw, atan2degq, atan2degll, atan2degdf, atan2degd, atan2degdl, atan2degdll - arc tangent function in degrees

SYNOPSIS

cc [ flags ] -I/usr/local/include file(s) -L/usr/local/lib -lmcw [ ... ]

#include <mathcw.h>

extern float atan2degf (float y, float x);

extern double atan2deg (double y, double x);

extern long double atan2degl (long double y, long double x);

extern __float80 atan2degw (__float80 y, __float80 x);

extern __float128 atan2degq (__float128 y, __float128 x);

extern long_long_double atan2degll (long_long_double y, long_long_double x);

extern decimal_float atan2degdf (decimal_float y, decimal_float x);

extern decimal_double atan2degd (decimal_double y, decimal_double x);

extern decimal_long_double atan2degdl (decimal_long_double y, decimal_long_double x);

extern decimal_long_long_double atan2degdll (decimal_long_long_double y,
                                             decimal_long_long_double x);

NB: Functions with prototypes containing underscores in type names may be available only with certain extended compilers.


DESCRIPTION

Compute the principal value of the arc tangent function in degrees, using the signs of both arguments to determine the quadrant of the return value. The value of y / x should be in the range [-Infinity,+Infinity], for which the function range is [-180,+180].

Special cases for negative zero are:

atan2deg(+0,pos) = +0
atan2deg(-0,pos) = -0
atan2deg(+0,neg) = +180
atan2deg(-0,neg) = -180
These also apply when the second argument is zero.

RETURN VALUES

For in-range arguments, the returned value is in the range [-180, +180]. Otherwise, the returned value is a quiet NaN.

ERRORS

For NaN arguments, the returned value is a quiet NaN, and errno is set to EDOM.

SEE ALSO

acosdeg(3CW), asindeg(3CW), atandeg(3CW), cosdeg(3CW), cotandeg(3CW), sindeg(3CW), tandeg(3CW).