title: How can I get the y-axis of a lattice xyplot to display fractions as percentages?
body: <p>I'd like to be able to display the y-axis of my lattice xyplot in percentage units (e.g. 0.45 = 45%).</p>
  
  <p>Here's an example with some fake industrial process yield data:</p>
  
  <pre><code>library(lattice)
  set.seed(1234)
  my.df &lt;- data.frame(period=c(1:20),
                      n=floor(runif(n=20,min=40,max=80)),
                      d=rpois(n=20,lambda=5))
  my.df$yield &lt;- (my.df$n-my.df$d)/my.df$n
  xyplot(yield~period,data=my.df)
  </code></pre>
  
  <p><img src="https://i.stack.imgur.com/jZeMd.png" alt="example plot"></p>
  
  <p>I'd like the y-axis labels above to instead be 80%, 85%, 90%, 95%</p>
  
  <p>My <code>yield</code> variable is a fraction expressed as a decimal in the range (0 &lt;= yield &lt;= 1).
  I don't want to have to pre-process the data in the data.frame, (e.g. multply by 100), I'd like this to be taken care of by the plotting action.</p>