title: Change the size of a UISlider thumbImage
body: <p>How can I change the size of a UIImage that I am using as a thumbImage.  The code I use to set the image is as follows.</p>
  
  <pre><code>let image: UIImage = UIImage(assetIdentifier: UIImage.AssetIdentifier.Slider)
  </code></pre>
  
  <p>I use an Enum to get the image, no problem there.</p>
  
  <p>The code I use to set the thumbImage is as follows.</p>
  
  <pre><code>self.setThumbImage(image, forState: UIControlState.Normal)
  </code></pre>
  
  <p>I have tried using the code below to change the thumb images size but cannot find the solution.  </p>
  
  <pre><code>let trackRect: CGRect = CGRect(x: 0.0, y: 0, width: self.frame.size.width, height: self.frame.size.height)
  let thumbRect: CGRect = CGRect(x: 0.0, y: 0.0, width: 12.0, height: 12.0)
  thumbRectForBounds(thumbRect, trackRect: trackRect, value: 0.0)
  </code></pre>
  
  <p>The image is currently about 40pt by 40pt (Its a circle).  I would like the image to be around 24pt by 24pt.</p>
  
  <p>Also, this is in Swift 2 on XCode 7. I understand those methods are for iOS8.0 or above and that is my deployment target.</p>