title: Plot only Edges with a specific weight - igraph
body: <p>I have a really large edge list, and I would like to plot only the edges that have a particular weight, how can I do that?</p>
  
  <p>I have so far tried</p>
  
  <pre><code>plot.graph(E(sgdf)[E(sgdf)$weight==3]))
  </code></pre>
  
  <p>but I always get this error</p>
  
  <pre><code>Error in V(g) : Not a graph object
  </code></pre>