atan2 [function]

atan2( y, x )

returns the extended arctangent of y/x (angle in radians), as real

• Signs of x and y are used to determine the quadrant, thus y is expected to be the sine of the angle to be returned (the y coordinate of a point) and x - the cosine (the x coordinate).

Due to the common requirement to use this function to determine the angle between two somewhat random points (usually from a simulation), it will not emit a warning when both arguments are 0 - it will return 0 instead.

atan2( 0, 1 ); // real (0)
atan2( 1, 0 ); // real (1.5708)
atan2( -1, -1 ); // real (-2.35619)
atan2( 0, 0 ); // real (0)