title: Isolate singletons in groups using Stienen sets and dilation
body: <p>I would like to form groups of points using Steiner sets (<code>spatstat::dilation</code>).</p>
  
  <p>There are singletons which need to be removed, and I am thinking of using Stienen sets (<code>spatstat::stienenSet</code>) for that: for singletons Stienen > Steiner.</p>
  
  <p>How can this be done? </p>
  
  <pre><code>library(spatstat)
  
  a=stienenSet(redwood)
  b=dilation(redwood, r=0.03)
  
  plot(a, col='orange', main="")
  plot(b,add=T, main="")
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/zr4ZL.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/zr4ZL.png" alt="enter image description here"></a></p>