Objective C procedure to draw a circle with Radius R

gistfile1.m

-(void) createCircle :(int) R
{
    CALayer *circleLayer = [CALayer layer];
    circleLayer.bounds = CGRectMake(0, 0, 2*R, 2*R);
    circleLayer.position = self.view.center;
    circleLayer.cornerRadius = R;
    circleLayer.borderColor = [UIColor blackColor].CGColor;
    circleLayer.borderWidth = 8;
    [self.view.layer addSublayer:circleLayer];
}