On 12/01/2016 05:33 PM, John Cowan wrote:
>
>
> On Mon, Nov 21, 2016 at 10:34 AM, Jim Rees <xxxxxx@gmail.com
> <mailto:xxxxxx@gmail.com>> wrote:

>     ..except that atan2 does not return the same thing as atan(y/x).
>
>
> I thought that was the whole point of atan2.
>  http://en.cppreference.com/w/cpp/numeric/math/atan2 says
> "Computes the arc tangent of y/x using the signs of arguments
> to determine the correct quadrant."

I think Jim means that atan(y/x) returns a result only between $-\pi/2$
and $\pi/2$, it can't return results in the other quadrants as atan2 can.

Brad