datatable.math.atan2()¶
The inverse trigonometric tangent of y/x, taking into account the signs
of x and y to produce the correct result.
If (x,y) is a point in a Cartesian plane, then arctan2(y, x) returns
the radian measure of an angle formed by two rays: one starting at the origin
and passing through point (0,1), and the other starting at the origin
and passing through point (x,y). The angle is assumed positive if the
rotation from the first ray to the second occurs counter-clockwise, and
negative otherwise.
As a special case, arctan2(0, 0) == 0, and arctan2(0, -1) == tau/2.