title: Referencing operator function '*' on 'SIMD' requires that '_.Scalar' conform to 'FloatingPoint'
body: <p>I've just started teaching myself to write in Swift. I'm currently trying to rotate an image when I press a button (just practicing with really simple stuff) and Xcode has thrown two errors at me:</p>
  <blockquote>
  <p>Referencing operator function '*' on 'SIMD' requires that '_.Scalar' conform to 'FloatingPoint'</p>
  <p>String interpolation can only appear inside a string literal</p>
  </blockquote>
  <p>I've searched around the web a bit for info on SIMD but I couldn't understand any of it! Can someone break it down for a clueless newbie? This is my code so far. Some of it is from online tutorials, some from Xcode's suggestions, some I just guessed:</p>
  <pre><code>@IBAction func spinButton(_ sender: Any) {
  
      if self.rotationDegree != 360 {
          self.rotationDegree += 1
          //to increase the rotation by 1 degree  
      } else {
          self.rotationDegree -= 360
          //to put the rotation back to 0 degrees   
      }
      
      UIView.animate(withDuration: 1.0, animations: {
          self.vortex2.transform = CGAffineTransform(rotationAngle: \(rotationDegree) * .pi / \(rotationDegree))
          //this is where both error messages appear
      })
  
  }
  </code></pre>