.. _program_listing_file_lib_graph_modification.cpp:

Program Listing for File graph_modification.cpp
===============================================

|exhale_lsh| :ref:`Return to documentation for file <file_lib_graph_modification.cpp>` (``lib/graph_modification.cpp``)

.. |exhale_lsh| unicode:: U+021B0 .. UPWARDS ARROW WITH TIP LEFTWARDS

.. code-block:: cpp

   #include "AnalysisGraph.hpp"
   
   using namespace std;
   using namespace delphi::utils;
   
   
   /*
    ============================================================================
    Public: Graph Modification
    ============================================================================
   */
   
   void AnalysisGraph::prune(int cutoff) {
     int num_verts = this->num_vertices();
     int src_degree = -1;
     int tgt_degree = -1;
   
     for (int tgt = 0; tgt < num_verts; ++tgt) {
       for (int src = 0; src < num_verts; ++src) {
         if (this->A_beta_factors[tgt][src] &&
             this->A_beta_factors[tgt][src]
                 ->has_multiple_paths_longer_than_or_equal_to(cutoff)) {
           // src_degree = this->get_degree(src);
           // tgt_degree = this->get_degree(tgt);
   
           // if (src_degree != 1 && tgt_degree != 1) {
           // This check will always be true.
           // If there is a direct edge src --> tgt and
           // if there are multiple paths, then the degree
           // will always be > 1
           pair<int, int> edge = make_pair(src, tgt);
   
           // edge ≡ β
           if (in(this->beta2cell, edge)) {
             // There is a direct edge src --> tgt
             // Remove that edge
             boost::remove_edge(src, tgt, this->graph);
           }
         }
       }
     }
     // Recalculate all the directed simple paths
     this->find_all_paths();
   }
   
   void AnalysisGraph::merge_nodes(string concept_1,
                                   string concept_2,
                                   bool same_polarity) {
     // Check whetehr concept_1 and concept_2 are in the CAG
     this->get_vertex_id(concept_1);
     this->get_vertex_id(concept_2);
   
     for (int predecessor : this->predecessors(concept_1)) {
       Edge& edge_to_remove = this->edge(predecessor, concept_1);
       vector<Statement>& evidence_move = edge_to_remove.evidence;
       if (!same_polarity) {
         for (Statement stmt : edge_to_remove.evidence) {
           stmt.object.polarity = -stmt.object.polarity;
         }
       }
   
       // Add the edge predecessor --> vertex_to_keep
       auto edge_to_keep = this->add_edge(predecessor, concept_2).first;
   
       // Move all the evidence from vertex_delete to the
       // newly created (or existing) edge
       // predecessor --> vertex_to_keep
       vector<Statement>& evidence_keep = this->edge(edge_to_keep).evidence;
   
       evidence_keep.resize(evidence_keep.size() + evidence_move.size());
   
       move(evidence_move.begin(),
            evidence_move.end(),
            evidence_keep.end() - evidence_move.size());
     }
   
     for (int successor : this->successors(concept_1)) {
   
       // Get the edge descriptor for
       //                   vertex_to_remove --> successor
       Edge& edge_to_remove = this->edge(concept_1, successor);
       vector<Statement>& evidence_move = edge_to_remove.evidence;
   
       if (!same_polarity) {
         for (Statement stmt : edge_to_remove.evidence) {
           stmt.subject.polarity = -stmt.subject.polarity;
         }
       }
   
       // Add the edge   successor --> vertex_to_keep
       auto edge_to_keep = this->add_edge(concept_2, successor).first;
   
       // Move all the evidence from vertex_delete to the
       // newly created (or existing) edge
       // vertex_to_keep --> successor
       vector<Statement>& evidence_keep = this->edge(edge_to_keep).evidence;
   
       evidence_keep.resize(evidence_keep.size() + evidence_move.size());
   
       move(evidence_move.begin(),
            evidence_move.end(),
            evidence_keep.end() - evidence_move.size());
     }
   
     // Remove vertex_to_remove from the CAG
     // Note: This is an overloaded private method that takes in a vertex id
     this->remove_node(concept_1);
   }
   
   void AnalysisGraph::change_polarity_of_edge(string source_concept,
                                               int source_polarity,
                                               string target_concept,
                                               int target_polarity) {
     int src_id = this->get_vertex_id(source_concept);
     int tgt_id = this->get_vertex_id(target_concept);
   
     pair<int, int> edge = make_pair(src_id, tgt_id);
   
     // edge ≡ β
     if (in(this->beta2cell, edge)) {
       // There is a edge from src_concept to tgt_concept
       // get that edge object
       auto e = boost::edge(src_id, tgt_id, this->graph).first;
   
       this->graph[e].change_polarity(source_polarity, target_polarity);
     }
   }