GNU/Linux |
CentOS 4.8 |
i386 |
atan2l(3) |
atan2, atan2f, atan2l − arc tangent function of two variables
#include <math.h>
double atan2(double y, double x);
float atan2f(float y, float x);
long double atan2l(long double y, long double x);
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.
The atan2() function returns the result in radians, which is between -PI and PI (inclusive).
SVID 3, POSIX, BSD 4.3, ISO 9899. The float and long double variants are C99 requirements.
acos(3), asin(3), atan(3), cos(3), sin(3), tan(3)
atan2l(3) |