atan2, atan2f—arc tangent of y/x #include <math.h>
double atan2(double y,double x);
float atan2f(float y,float x);
Description
atan2 computes the inverse tangent (arc tangent) of y/x.
atan2 produces the correct result even for angles near
pi/2 or -pi/2
(that is, when x is near 0).
atan2f is identical to atan2, save that it takes and returns
float.
Returns
atan2 and atan2f return a value in radians, in the range of
-pi to pi.
You can modify error handling for these functions using matherr.
Portability
atan2 is ANSI C. atan2f is an extension.