degree_cent.gsql

CREATE TEMPLATE QUERY GDBMS_ALGO.centrality.degree_cent(SET<STRING> v_type_set, SET<STRING> e_type_set, SET<STRING> reverse_e_type_set, BOOL in_degree = TRUE, BOOL out_degree = TRUE,
  INT top_k=100, BOOL print_results = TRUE, STRING result_attribute = "",STRING file_path = "", BOOL normalize = TRUE) SYNTAX V1 {
    /*
        First Author: <First Author Name>
        First Commit Date:  <First Commit Date>

        Recent Author: Rob Rossmiller
        Recent Commit Date: 05/2024


        Repository:
            https://github.com/tigergraph/gsql-graph-algorithms/tree/master/algorithms/Centrality

        Maturity:
            Production

        Description: 
            Compute degree Centrality for each VERTEX.
            for undirected graph, you only need to set e_type_set and indegree

        Publications:
            NA

        TigerGraph Documentation:
            https://docs.tigergraph.com/graph-ml/current/centrality-algorithms/degree-centrality

        Parameters:
            v_type_set:
                vertex types to traverse
            e_type_set:
                edge types to traverse
            reverse_e_type_set:
                for indegree use
            in_degree:
                If True, count incoming relationships
            out_degree:
                If True, count outcoming relationships
            top_k:
                report only this many top scores
            print_results:
                If True, print the result
            result_attribute:
                attribute to write result to
            file_path:
                file to write CSV output to
            normailize:
                If True, return the normalized centrality. Default: True 
  */

  TYPEDEF TUPLE<VERTEX Vertex_ID, FLOAT score> Vertex_Score;
  HeapAccum<Vertex_Score>(top_k, score DESC) @@top_scores_heap;
  SumAccum<DOUBLE> @sum_degree_score;
  FILE f (file_path);

  all = {v_type_set};
  sll = SELECT s 
        FROM all:s
        ACCUM 
            IF in_degree THEN
                s.@sum_degree_score += s.outdegree(reverse_e_type_set)
            END,
            IF out_degree THEN
                s.@sum_degree_score += s.outdegree(e_type_set)
            END
        POST-ACCUM 
            IF normalize THEN
                s.@sum_degree_score = s.@sum_degree_score / (all.size() - 1)
            END;

  #Output
  IF file_path != "" THEN
      f.println("Vertex_ID", "Degree");
  END;

  Start = SELECT s 
          FROM all:s
	  POST-ACCUM
	      IF result_attribute != "" THEN 
                  s.setAttr(result_attribute, s.@sum_degree_score) 
              END,
    
	      IF print_results THEN 
                  @@top_scores_heap += Vertex_Score(s, s.@sum_degree_score) 
              END,
    
	      IF file_path != "" THEN 
                  f.println(s, s.@sum_degree_score) 
              END;
	      
   IF print_results THEN
       PRINT @@top_scores_heap AS top_scores;
   END;
}