Merge pull request #390 from bedupako12mas/centrality-week5

Centrality Week-5

doc/metrics/pgr_betweennessCentrality.rst

@@ -0,0 +1,111 @@
+..
+   ****************************************************************************
+    pgRouting Manual
+    Copyright(c) pgRouting Contributors
+
+    This documentation is licensed under a Creative Commons Attribution-Share
+    Alike 3.0 License: https://creativecommons.org/licenses/by-sa/3.0/
+   ****************************************************************************
+
+|
+
+
+``pgr_betweennessCentrality``
+===============================================================================
+
+``pgr_betweennessCentrality`` - Returns the relative betweeness centrality of 
+all edges in a graph using Brandes Algorithm.
+
+.. figure:: images/boost-inside.jpeg
+   :target: https://www.boost.org/doc/libs/1_84_0/libs/graph/doc/betweenness_centrality.html
+
+   Boost Graph Inside
+
+.. rubric:: Availability
+.. TODO: Add availability
+
+Description
+-------------------------------------------------------------------------------
+
+The Brandes Algorithm for utilises the sparse nature of graphs to evaluating the
+betweenness centrality score of all edges/vertices.
+We use Boost's implementation which runs in :math:`\Theta(VE)` for unweighted 
+graphs and :math:`Theta(VE + V(V+E)log(V))` for weighted graphs and uses
+:math:`\Theta(VE)` space.
+
+Signatures
+-------------------------------------------------------------------------------
+
+.. rubric:: Summary
+
+.. admonition:: \ \
+   :class: signatures
+
+   pgr_betweennessCentrality(`Edges SQL`_, [``directed``])
+
+   | Returns set of ```(seq, edge_id, betweenness_centrality)``` 
+   | OR EMPTY SET
+
+.. TODO: Fix this when docqueries are made 
+:Example: For a directed subgraph with edges :math:`\{1, 2, 3, 4\}`.
+
+.. literalinclude:: floydWarshall.queries
+   :start-after: -- q1
+   :end-before: -- q2
+
+Parameters
+-------------------------------------------------------------------------------
+
+.. include:: allpairs-family.rst
+    :start-after: edges_start
+    :end-before: edges_end
+
+Optional parameters
+...............................................................................
+
+.. include:: dijkstra-family.rst
+    :start-after: dijkstra_optionals_start
+    :end-before: dijkstra_optionals_end
+
+Inner Queries
+-------------------------------------------------------------------------------
+
+Edges SQL
+...............................................................................
+
+.. include:: pgRouting-concepts.rst
+    :start-after: no_id_edges_sql_start
+    :end-before: no_id_edges_sql_end
+
+Result columns
+-------------------------------------------------------------------------------
+
+.. list-table::
+	:width: 81
+	:widths: auto
+	:header-rows: 1
+
+	* - Column
+	  - Type
+	  - Description
+	* - ``seq``
+	  - ``INTEGER``
+	  - Sequential Value starting from ``1``
+	* - ``edge_id``
+	  - ``BIGINT``
+	  - Identifier of the edge
+	* - ``centrality``
+	  - ``FLOAT``	
+	  - relative betweenness centrality score of the edge (will be in range [0,1])
+
+See Also
+-------------------------------------------------------------------------------
+
+* Boost `centrality
+  <https://www.boost.org/doc/libs/1_84_0/libs/graph/doc/betweenness_centrality.html>`_
+* Queries uses the :doc:`sampledata` network.
+
+.. rubric:: Indices and tables
+
+* :ref:`genindex`
+* :ref:`search`

docqueries/metrics/CMakeLists.txt

@@ -1,6 +1,6 @@
 # Do not use extensions
 SET(LOCAL_FILES
-    centrality.pg
+	betweennessCentrality.pg
     )
 
 foreach (f ${LOCAL_FILES})

docqueries/metrics/centrality.pg → docqueries/metrics/betweennessCentrality.pg

@@ -1,7 +1,7 @@
 -- CopyRight(c) pgRouting developers
 -- Creative Commons Attribution-Share Alike 3.0 License : https://creativecommons.org/licenses/by-sa/3.0/
 /* -- q1 */
-SELECT * FROM pgr_centrality(
+SELECT * FROM pgr_betweennesscentrality(
   'SELECT id, source, target, cost, reverse_cost
   FROM edges where id < 5'
 ) ORDER BY start_vid, end_vid;

docqueries/metrics/centrality.result → docqueries/metrics/betweennessCentrality.result

@@ -3,7 +3,7 @@ BEGIN
 SET client_min_messages TO NOTICE;
 SET
 /* -- q1 */
-SELECT * FROM pgr_centrality(
+SELECT * FROM pgr_betweennesscentrality(
   'SELECT id, source, target, cost, reverse_cost
   FROM edges where id < 5'
 ) ORDER BY start_vid, end_vid;

docqueries/metrics/test.conf

@@ -3,7 +3,7 @@
 %main::tests = (
     'any' => {
         'files' => [qw(
-            centrality.pg
+            betweennessCentrality.pg
             )]
     },
 # I don't know what this are for or how to use them.

include/drivers/metrics/centrality_driver.h → include/drivers/metrics/betweennessCentrality_driver.h

@@ -1,5 +1,5 @@
 /*PGR-GNU*****************************************************************
-File: floydWarshall_driver.h
+File: betweennessCentrality_driver.h
 
 Generated with Template by:
 Copyright (c) 2015 pgRouting developers
@@ -27,8 +27,8 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
  ********************************************************************PGR-GNU*/
 
-#ifndef INCLUDE_DRIVERS_METRICS_CENTRALITY_DRIVER_H_
-#define INCLUDE_DRIVERS_METRICS_CENTRALITY_DRIVER_H_
+#ifndef INCLUDE_DRIVERS_METRICS_BETWEENNESSCENTRALITY_DRIVER_H_
+#define INCLUDE_DRIVERS_METRICS_BETWEENNESSCENTRALITY_DRIVER_H_
 #pragma once
 
 /* for size-t */
@@ -48,7 +48,7 @@ extern "C" {
 #endif
 
 void
-pgr_do_centrality(
+pgr_do_betweennesscentrality(
     char*,
     bool,
 
@@ -61,4 +61,4 @@ pgr_do_centrality(
 }
 #endif
 
-#endif  // INCLUDE_DRIVERS_METRICS_CENTRALITY_DRIVER_H_
+#endif  // INCLUDE_DRIVERS_METRICS_BETWEENNESSCENTRALITY_DRIVER_H_

include/metrics/centrality.hpp → include/metrics/betweennessCentrality.hpp

@@ -1,5 +1,5 @@
 /*PGR-GNU*****************************************************************
-File: centrality.hpp
+File: betweennessCentrality.hpp
 
 Copyright (c) 2015 pgRouting developers
 Mail: project@pgrouting.org
@@ -26,22 +26,18 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  ********************************************************************PGR-GNU*/
 
 
-#ifndef INCLUDE_METRICS_CENTRALITY_HPP_
-#define INCLUDE_METRICS_CENTRALITY_HPP_
+#ifndef INCLUDE_METRICS_BETWEENNESSCENTRALITY_HPP_
+#define INCLUDE_METRICS_BETWEENNESSCENTRALITY_HPP_
 #pragma once
 
-#include <deque>
 #include <vector>
-#include <set>
-#include <limits>
+#include <map>
 
 #include <boost/config.hpp>
 #include <boost/graph/adjacency_list.hpp>
 #include <boost/property_map/property_map.hpp>
 #include <boost/graph/betweenness_centrality.hpp>
 #include <boost/graph/graph_traits.hpp>
-#include <boost/graph/johnson_all_pairs_shortest.hpp>
-#include <boost/graph/floyd_warshall_shortest.hpp>
 
 #include "c_types/iid_t_rt.h"
 #include "cpp_common/basePath_SSEC.hpp"
@@ -52,20 +48,13 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 #include "cpp_common/pgr_alloc.hpp"
 
 namespace pgrouting  {
-template < class G > class Pgr_metrics;
+template <class G> class Pgr_metrics;
 
-// user's functions
-template < class G >
-void
-pgr_centrality(G &graph, std::vector< IID_t_rt> &rows) {
-    Pgr_metrics< G > fn_centrality;
-    fn_centrality.centrality(graph, rows);
-}
 
 // for postgres
-template < class G >
+template <class G>
 void
-pgr_centrality(
+pgr_betweennesscentrality(
         G &graph,
         size_t &result_tuple_count,
         IID_t_rt **postgres_rows) {
@@ -75,7 +64,7 @@ pgr_centrality(
 
 
 // template class
-template < class G >
+template <class G>
 class Pgr_metrics {
  public:
 	 using Graph = typename G::B_G;
@@ -85,50 +74,47 @@ class Pgr_metrics {
 			 const G &graph,
 			 size_t &result_tuple_count,
 			 IID_t_rt **postgres_rows ){
-		 	 std::map<int64_t, double> centrality_map;
-			 std::vector<double> centrality_score(boost::num_vertices(graph.graph));
+
+		 std::vector<double> centrality(boost::num_vertices(graph.graph), 0.0);
+		 auto centrality_map = boost::make_iterator_property_map(centrality.begin(),
+				 												 boost::get(boost::vertex_index, graph.graph)
+				 												);
 
 		 /* abort in case of an interruption occurs (e.g. the query is being cancelled) */
 		 CHECK_FOR_INTERRUPTS();
 		 boost::brandes_betweenness_centrality(
 				 graph.graph,
-				 boost::centrality_map(
-					 boost::make_iterator_property_map(
-						 centrality_score.begin(),
-						 boost::get(boost::vertex_index, graph.graph)
-					 )
-				 )
+				 centrality_map
 		 );
-
-		 typename boost::graph_traits<Graph>::vertex_iterator vi, vi_end;
-		 for(boost::tie(vi, vi_end) = boost::vertices(graph.graph); vi != vi_end; ++vi) {
-			 int64_t id = graph.graph[*vi].id;
-			 centrality_map[id] = centrality_score[boost::get(boost::vertex_index, graph.graph, *vi)];
+		 if(boost::num_vertices(graph.graph) > 2){
+		 	boost::relative_betweenness_centrality(
+				 graph.graph,
+				 centrality_map
+		 	);
 		 }
 
-		 generate_results(centrality_map, result_tuple_count, postgres_rows);
-
+		 generate_results(graph, centrality, result_tuple_count, postgres_rows);
 	 }
 
  private:
 	 void generate_results(
-			 const std::map<int64_t, double> centrality_results,
+			 const G &graph,
+			 const std::vector<double> centrality_results,
 			 size_t &result_tuple_count,
 			 IID_t_rt **postgres_rows) const {
 		 result_tuple_count = centrality_results.size();
 		 *postgres_rows = pgr_alloc(result_tuple_count, (*postgres_rows));
 
-
 		 size_t seq = 0;
-		 for(auto results : centrality_results) {
-		 	(*postgres_rows)[seq].from_vid = results.first;
+	 	 for(typename G::V v_i = 0; v_i < graph.num_vertices(); ++v_i) {
+		 	(*postgres_rows)[seq].from_vid = graph[v_i].id;
 			(*postgres_rows)[seq].to_vid = 0;
-			(*postgres_rows)[seq].cost = results.second;
-			seq++;		
+			(*postgres_rows)[seq].cost = centrality_results[v_i];
+			seq++;
 		 }
 	 }
 };
 
 }  // namespace pgrouting
 
-#endif  // INCLUDE_METRICS_CENTRALITY_HPP_
+#endif  // INCLUDE_METRICS_BETWEENNESSCENTRALITY_HPP_

sql/metrics/CMakeLists.txt

@@ -1,7 +1,7 @@
 
 SET(LOCAL_FILES
-    _centrality.sql
-    centrality.sql
+    _betweennessCentrality.sql
+    betweennessCentrality.sql
 )
 
 foreach (f ${LOCAL_FILES})

sql/metrics/_centrality.sql → sql/metrics/_betweennessCentrality.sql

@@ -1,6 +1,6 @@
 /*PGR-GNU*****************************************************************
 
-File: _centrality.sql
+File: _betweennessCentrality.sql
 
 Template:
 Copyright (c) 2015 pgRouting developers
@@ -28,23 +28,22 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
  ********************************************************************PGR-GNU*/
 
----------------------
--- pgr_centrality
----------------------
+--------------------------------
+-- pgr_betweennessCentrality
+--------------------------------
 
 --v3.7
-CREATE FUNCTION _pgr_centrality(
+CREATE FUNCTION _pgr_betweennesscentrality(
     edges_sql TEXT,
     directed BOOLEAN,
 
-    OUT start_vid BIGINT,
-    OUT end_vid BIGINT,
-    OUT agg_cost FLOAT)
+    OUT vid BIGINT,
+    OUT betweenness_centrality FLOAT)
 RETURNS SETOF RECORD AS
 'MODULE_PATHNAME'
 LANGUAGE C VOLATILE STRICT;
 
 -- COMMENTS
 
-COMMENT ON FUNCTION _pgr_centrality(TEXT, BOOLEAN)
+COMMENT ON FUNCTION _pgr_betweennesscentrality(TEXT, BOOLEAN)
 IS 'pgRouting internal function';