Function to print circle of Asterisk in Objective C

asteriskCricle

-(void) asteriskCircleWidthRadius:(CGFloat)rad filled:(BOOL) fill border:(NSUInteger) borderW{
    borderW -= 1;
    CGFloat dia = (rad + borderW) * 2;
    CGFloat centerX,centerY;
    centerX = centerY = dia/2.0; //-1 for
    
    
    NSMutableString *op = [NSMutableString string];
    NSMutableString *opCircle = [NSMutableString string];
    [op appendString:@"\n"];
    [opCircle appendString:@"\n"];
    for (NSUInteger x = 0; x<=dia; x++) {
        
        for (NSUInteger y = 0; y<=dia; y++) {
            double dis = sqrt((x-centerX)*(x-centerX) + (y-centerY)*(y-centerY));
            [op appendFormat:@"%5.02f ",dis];
            
            CGFloat tolerance = borderW + 0.4;
            if ((dis >= (rad - tolerance) || fill) && (dis <= (rad + tolerance))) {
                [opCircle appendString:@"* "];
            }else {
                [opCircle appendString:@"  "];
            }
        }
        [op appendString:@"\n"];
        [opCircle appendString:@"\n"];
    }
    
    //NSLog(@"%@",op);
    NSLog(@"%@",opCircle);
}

Sample output

              * * * * *               
          * * * * * * * * *           
      * * * * * * * * * * * * *       
    * * * * *           * * * * *     
    * * *                   * * *     
  * * *                       * * *   
  * * *                       * * *   
* * *                           * * * 
* * *                           * * * 
* * *                           * * * 
* * *                           * * * 
* * *                           * * * 
  * * *                       * * *   
  * * *                       * * *   
    * * *                   * * *     
    * * * * *           * * * * *     
      * * * * * * * * * * * * *       
          * * * * * * * * *           
              * * * * *