title: R - change size of axis labels with ROCR
body: <p><br>
  I want to increase the size of the axis labels. The data contains ROC curves, drawn by <a href="http://rocr.bioinf.mpi-sb.mpg.de/" rel="nofollow">ROCR</a>. </p>
  
  <pre><code>library(ROCR)
  # load the sample data and create an performance object
  data(ROCR.hiv)
  pp &lt;- ROCR.hiv$hiv.svm$predictions
  ll &lt;- ROCR.hiv$hiv.svm$labels
  par(mfrow=c(2,2)) 
  pred&lt;- prediction(pp, ll)
  perf &lt;- performance(pred, measure="tpr", x.measure = "fpr")
  </code></pre>
  
  <p>Some manipulations on the figure work, others, like setting <code>cex.axis</code>, not. Here's an example:</p>
  
  <pre><code># try different manipulations
  plot(perf) # normal layout
  plot(perf, cex.axis=2) # no change 
  plot(perf, col.axis="red") # no change 
  plot(perf, col.main="red", cex.main=3, main="abc") # the header may be manipulated
  </code></pre>
  
  <p>it seems like <code>cex.axis</code> is not set correctly, because</p>
  
  <pre><code>plot(perf, cex.axis=2) 
  par()
  </code></pre>
  
  <p>shows, that</p>
  
  <pre><code>$cex.axis
  [1] 1
  </code></pre>
  
  <p>any ideas?
  Thank you!</p>