atan2
computes the inverse tangent (arc tangent)
of y/x.
atan2 produces
the correct result even for angles near 
/2
or /2,
that is, when x
is near 0).
atan2f is identical to atan2, save that it takes and returns float.
atan2,
atan2f
[arc tangent
of y/x]
SYNOPSIS
#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 /2
or /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
to .
If both x
and y
are 0.0, atan2
causes a DOMAIN
error.
You can modify error handling for these functions using matherr.
COMPLIANCE
atan2
is ANSI C. atan2f
is an extension.