title: CGAffineTransform to scale width and height only
body: <p>How to scale a CGontext without affecting its origin i.e only the width and height should get scaled? If I use scale like the below one directly it scales the origin also.</p>
  
  <p><code>context.scaledBy(x: 2.0, y: 2.0)</code></p>
  
  <p>Is there a way to construct an AffineTransform that manipulates the width and height, leaving the origin untouched?</p>
  
  <p>I want an AffineTransform that can be used to both <code>CGContext</code> and <code>CGRect</code>.</p>
  
  <p>For example a <code>CGRect rect = {x, y, w, h}</code></p>
  
  <pre><code>var t = CGAffineTransform.identity
  t = t.scaledBy(x: sx, y: sy)
  let tRect = rect.applying(t)
  </code></pre>
  
  <p><code>tRect</code> will be <code>{x * sx, y * sy, w * sx, h * sy}</code></p>
  
  <p>But I want <code>{x, y, w * sx, h * sy}</code>. Though it can be achieved by calculation, I need CGAffineTransform to do this.</p>