title: Trouble in changing thickness of line segments in base plot
body: <p>I have a <code>pppmatching</code> object to plot (using the base plot function) where I need to change the thickness of line segments. Unfortunately, it seems that <code>lwd</code> is somehow changing the thickness of the <strong>plot border</strong> instead of the <strong>line segments</strong>! I am puzzled how to get around this.</p>
  
  <p>Reproducible example:</p>
  
  <pre><code>library(spatstat)
  set.seed(140627)
  X &lt;- runifpoint(300)
  Y &lt;- runifpoint(500)
  m &lt;- pppdist(X, Y)
  m
  
  plot(m, lwd = 5) #???
  ## End(Not run)
  </code></pre>