gistfile1.txt

    // Draw a point (filled circle)
    CGContextFillEllipseInRect(context, CGRectMake(xVal, yVal, 5, 5));
     CGFloat red[4] = {1.0f, 0.0f, 0.0f, 1.0f};
    CGContextSetFillColor(context, red);
    
    //----- AXIS
    CGFloat white[4] = {1.0f, 1.0f, 1.0f, 1.0f};
    CGContextSetStrokeColor(context, white);
    CGContextBeginPath(context);
    
    //Vert Line
    CGContextMoveToPoint(context, 25, 25);
    CGContextAddLineToPoint(context, 25, 275);
    
    //Horiz Line
    CGContextMoveToPoint(context, 25, 275);
    CGContextAddLineToPoint(context, 275, 275);
    CGContextStrokePath(context); 
    //----- END AXIS