User login |
atan2 (3)
ATAN2(3) Linux Programmer's Manual ATAN2(3)
NAME
atan2, atan2f, atan2l - arc tangent function of two variables
SYNOPSIS
#include <math.h>
double atan2(double y, double x);
float atan2f(float y, float x);
long double atan2l(long double y, long double x);
Link with -lm.
DESCRIPTION
The atan2() function calculates the arc tangent of the two variables x
and y. It is similar to calculating the arc tangent of y / x, except
that the signs of both arguments are used to determine the quadrant of
the result.
RETURN VALUE
The atan2() function returns the result in radians, which is between
-PI and PI (inclusive).
CONFORMING TO
SVr4, POSIX.1-2001, 4.3BSD, C89. The float and long double variants
are C99 requirements.
SEE ALSO
acos(3), asin(3), atan(3), cos(3), sin(3), tan(3)
2002-07-27 ATAN2(3)
|