title: backtransform `scale()` for plotting
body: <p>I have a explanatory variable that is centered using <code>scale()</code> that is used to predict a response variable:</p>
  
  <pre><code>d &lt;- data.frame(
    x=runif(100),
    y=rnorm(100)
  )
  
  d &lt;- within(d, s.x &lt;- scale(x))
  
  m1 &lt;- lm(y~s.x, data=d)
  </code></pre>
  
  <p>I'd like to plot the predicted values, but using the original scale of <code>x</code> rather than the centered scale. Is there a way to sort of backtransform or reverse scale <code>s.x</code>? </p>
  
  <p>Thanks!</p>