atan2 - arc tangent function of two variables


SYNOPSIS

       #include <math.h>

       double atan2(double y, double x);


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

       SVID 3, POSIX, BSD 4.3, ISO 9899


SEE ALSO

       acos(3), asin(3), atan(3), cos(3), sin(3), tan(3)