Yes ! that helps a lot,
thanks very much, vjoel !
-sk

On Fri, Dec 19, 2008 at 4:57 PM, Joel VanderWerf
<vjoel / path.berkeley.edu> wrote:
> shawn bright wrote:
>>
>> hey there all,
>>
>> ok, not really a ruby question, but did not know where to look.
>> i have a circle on a graph paper.
>> if i know the x and y of a point on the graph, if the center is at
>> 0,0, and i know the radius,
>> how can i find the angle that the point will be on the circumference?
>> somewhere between 1-360.
>>
>> would appreciate any tips, thanks
>> ok, if it is really against the grain to post this question here,
>> anyone have a recommendation of where to put it?
>> thanks all
>>
>> sk
>
> irb(main):007:0> Math.atan2(-1.0, -1.0)*180/Math::PI % 360
> => 225.0
> irb(main):008:0> Math.atan2(-1.0, 1.0)*180/Math::PI % 360
> => 315.0
> irb(main):009:0> Math.atan2(1.0, 1.0)*180/Math::PI % 360
> => 45.0
> irb(main):010:0> Math.atan2(1.0, -1.0)*180/Math::PI % 360
> => 135.0
>
> HTH.
>
> --
>      vjoel : Joel VanderWerf : path berkeley edu : 510 665 3407
>
>