Re: Inferring array index type from array object

[Simon Wright <simon@pushface.org>]

Adam Beneschan <adam@irvine.com> writes:

> By the way, I'm not sure that the error is the main reason for having
> this function.  The result of the two-argument arctan function is in
> the range -pi .. +pi, as opposed to -pi/2 .. +pi/2 for the one-
> argument variation; this allows you to get a result in any of the four
> quadrants (instead of just two), giving you the correct result when
> you want to compute the angle corresponding to a point (x, y) on a
> Cartesian graph.

And avoiding problems with the extremes; arctan (y / x) is a Bad Idea!