title: How to add values to a R plot with 4 subplots
body: <p>I have looked at this <a href="https://stackoverflow.com/questions/25449523/how-do-i-plot-two-models-into-one-graph?lq=1">post</a> but it is not quite what I want. Using superpose seems not to be working.</p>
  
  <p>the plot function in R is really powerful. Applied to different objects, will give different results. When applied to the results of the fevd function (from extRemes package), it constructs a 2x2 set of plots (that can be slightly different depending on the model). <a href="http://pybonacci.org/wp-content/uploads/2015/06/wpid-Trabajando_con_Python_y_R2.png" rel="nofollow noreferrer">here</a> you can find an example. </p>
  
  <p>After re-writing my own GEV fitting routines, I want to test my results against fevd's results. I want to plot my results on top of fevd's plots.</p>
  
  <p>How do I extract the handles (does R has handles? objects?) of the plots and tell R, for example:</p>
  
  <p>mimicking python</p>
  
  <pre><code>ax = plt.subplot(221)
  ax.plot(myxdata, myydata, 'o')
  </code></pre>
  
  <p>mimicking matlab</p>
  
  <pre><code>subplot(2,2,1)
  hold on
  plot(myxdata, myydata, 'o')
  </code></pre>
  
  <p>Thanks</p>