title: CGFloat comparison wrong
body: <p>in my app i'm checking if the the x-value of a CGPoint is different than zero in an if-statement. however, the app enters the if-statement although the x-value of the point is zero. here is the code:</p>
  
  <pre><code>CGPoint previousPoint;
  
       if (previousPoint.x != 0) {
              NSLog(@"YES");
              CGContextMoveToPoint(context, previousPoint.x, previousPoint.y);
              CGContextAddLineToPoint(context, 150+(40*[[[self.grades objectAtIndex:i] semesterGPA] doubleValue]), 59+(40*(i+1)));
          }
      }
  </code></pre>
  
  <p>After running the app "YES" is printed although it shouldn't as previousPoint is (0.000000, 0.000000) how can i fix this?</p>