R: Using GraphNEL, term frequency of extracted keywords

Question

I'm running the below code to extract key phrases from a raw data file. While i am successfully able to do it, i am not able to get the frequency or count of the extracted keywords which would help me understand the ranking of the occurrence of the keywords since i am using GraphNEL. Is there any way i can get the key phrase count? TIA.

ConstructTextGraph <- function(n)
 { 
  word_graph <- new("graphNEL")
  i <- 1
  while (i < length(words) ) {
    if ( IsSelectedWord(words[i]) ) {                                   
      links <- GetWordLinks(i,n)                                
      if (links[1] != "") {                                     
        cat(i," ",words[i]," - ",paste(c(links),collapse=" "),"\n")
        if ( length(which(nodes(word_graph)==words[i]))==0  ) {     
          word_graph <- addNode(words[i],word_graph)
        }                                               

        for (j in 1:length(links)) {
          if ( length(which(nodes(word_graph)==links[j]))==0 ) {
            word_graph <- addNode(links[j],word_graph)
            word_graph <- addEdge(words[i],links[j],word_graph,1)
          } 
          else {
            if ( length(which(edges(word_graph,links[j])[[1]]==words[i]))>0 ) { 
              prev_edge_weight <-    as.numeric(edgeData(word_graph,words[i],links[j],"weight"))
              edgeData(word_graph,words[i],links[j],"weight") <- prev_edge_weight+1
            }
            else {
              word_graph <- addEdge(words[i],links[j],word_graph,1)
            }
          } 
        }
      }
    }
    i <- i+1
  }
  word_graph
}

Please let me know if more information is needed.