title: question about igraph R - identical data in different nodes
body: <p>I use igraph and my input has some nodes with identical data. I use the euclidean distance as weights for my graph, so for these nodes the weight will be zero. Afterwards, I call the Leading Eigenvector algorithm and it produces the graph. The nodes which are identical appear in the middle of the graph, but not in the same place and I don't understand how they are ordered. </p>
  
  <p>Are there some criteria for the order of these nodes on the graph?</p>
  
  <p>I give you a subset of my data, as an example below.</p>
  
  <p>Example of input data:</p>
  
  <p><a href="https://i.stack.imgur.com/zmEOF.png" rel="nofollow noreferrer">sample data</a></p>
  
  <p>My nodes are x1, x2,...x4, where x1 and x2 have the same data.</p>
  
  <p>After calculating Euclidean distance with function dist, I get the distance table which I convert to matrix ed2 and use it as my weights for the graph, which is produced as follows:</p>
  
  <p>g &lt;- graph_from_data_frame(relations, directed=FALSE, vertices=nodes) 
  where nodes are x1 to x4 and relations are all possible relationships between them.</p>
  
  <p>E(g)$weight =ed2; #here I put the weights</p>
  
  <p>Thanks in advance!</p>