title: creating a bipartite graph in R with igraph with specific edge list
body: <p>I am new in R and also igraph. I want to make a bipartite graph between two nodes sets (one has 2115 nodes and another one has 4) with specified edge list. It sound easy but I have lots of difficulties for constructing it and so far no result. I would appreciate any help. Here is my piece of codes:</p>
  
  <pre><code>library(igraph)
  test &lt;- graph.data.frame(file.choose(), directed=T)
  edge &lt;- read.table(text="e1 e2
  779 958
  779 1293
  779 1503
  1124 97
  1124 151
  2078 979
  1970 344", header=T)
  edgels &lt;- graph.edgelist(as.matrix(edge))
  g &lt;- graph.bipartite(test, edgels, directed=T)
  </code></pre>
  
  <p>I don't know where my code is wrong and I guess it is all because I am new in this. Thanks so much for your helps.</p>