I'am trying to find out an algorithm to recognize circle in array of points. 

Lets say that I've got points array where circle could or could not be stored (that also means array doesn't have to store only circle's points, there could be some "extra" points before or after circle's data).

I've already tried some algorithms but none of them work properly with those "extra" points. Have you got any ideas how to deal with this problem? 

EDIT// I didn't mention that before. I want this algorithm to be used on circle gesture recognition. I've thought I would have data in array (for last few seconds) and by analysing this data in every tracking frame I would be able to say if there was or was not a circle gesture.