Add implementation of transformation of undirected graph to line graph

configuration.conf

@@ -29,7 +29,7 @@ pickDeliver         | Y | Y | N
 vrp_basic           | N | Y | Y
 vrppdtw             | N | Y | Y
 withPoints          | Y | Y | Y
-dijkstraTRSP        | Y | Y | Y
+#dijkstraTRSP        | Y | N | N
 lineGraph           | Y | Y | Y
 #areaContraction     | Y | Y | Y
 #connectedComponentsV | Y | Y | Y

doc/lineGraph/CMakeLists.txt

@@ -8,4 +8,6 @@ foreach (f ${LOCAL_FILES})
     list(APPEND LOCAL_DOC_FILES  ${PGR_DOCUMENTATION_SOURCE_DIR}/${f})
 endforeach()
 
+add_subdirectory("images")
 set(PgRouting_DOC_FILES ${PgRouting_DOC_FILES} ${LOCAL_DOC_FILES} PARENT_SCOPE)
+set(PgRouting_IMG_FILES ${PgRouting_IMG_FILES} PARENT_SCOPE)

doc/lineGraph/images/CMakeLists.txt

@@ -0,0 +1,19 @@
+SET(LOCAL_FILES
+    128px-Line_graph_construction_4.svg.png
+    135px-Line_graph_construction_1.svg.png
+    135px-Line_graph_construction_2.svg.png
+    135px-Line_graph_construction_3.svg.png
+
+    Graph1.png
+    Graph2.png
+
+    Line-graph-with-edge-cost.png
+    Line-graph-with-node-cost.png
+    )
+
+foreach (f ${LOCAL_FILES})
+    configure_file(${f} "${PGR_DOCUMENTATION_SOURCE_DIR}/images/${f}" COPYONLY)
+    list(APPEND LOCAL_IMG_FILES  "${PGR_DOCUMENTATION_SOURCE_DIR}/images/${f}")
+endforeach()
+
+set(PgRouting_IMG_FILES ${PgRouting_IMG_FILES} ${LOCAL_IMG_FILES} PARENT_SCOPE)

doc/lineGraph/pgr_lineGraph.rst

@@ -36,11 +36,6 @@ The current implementation only works for the `directed graph`.
 The following figures show a graph (left, with blue vertices) and its
 Line Graph (right, with green vertices).
 
-.. footer::
-
-    .. class:: tablapie
-
-    +-------------------------------------------------------------------------------------------------------------------------------------------------------+---------------------------------------------------------------------+----------------------------------+-----------------------------------+
 | |first|       |second|               |third|  |fourth|
 
 .. |first| image:: images/135px-Line_graph_construction_1.svg.png
@@ -55,41 +50,7 @@ Line Graph (right, with green vertices).
 .. |fourth| image:: images/128px-Line_graph_construction_4.svg.png
    :align: middle
 
-Handling of Costs
--------------------------------------------------------------------------------
-
-.. - **Cost associated with the nodes.**
-..    + Consider the following graph with nodes having costs:-
-..
-..    .. image:: images/Graph1.png
-..
-..    The transformed **Line Graph**:-
-..
-..    .. image:: images/Line-graph-with-edge-cost.png
-
-..    Each node of the transformed graph is an edge from the original graph.
-..    Here `[1,2]` denotes the node in the transformed graph which was an edge
-..    from node `1` to node `2` in the original graph.
-
-..    Each edge of the transformed graph is a tuple of nodes `(n1, n2, n3)` where
-..    `n1`, `n2` and `n3` are nodes from the original graph such that there was
-..    an edge from `n1 -> n2` and another edge from `n2 -> n3`.
-
-..    Thus, the connection `[1,4] -> [3, 4]` goes through the vertex `4` as it is
-..    made up of `(1, 4, 3)` tuple which has an associated cost of `6` therefore
-..    the corresponding edge in the above graph gets a cost of `6`.
-
-- **Cost associated with the edges**
-    + Consider the following graph with edges having costs:-
-
-    .. image:: images/Graph2.png
-
-    The transformed **Line Graph**:-
-
-    .. image:: images/Line-graph-with-node-cost.png
-
-    Here, the cost associated with an edge in the original graph moves to the
-    corresponding nodes in the transformed Line Graph.
+.. The images are taken from https://en.wikipedia.org/wiki/Line_graph.
 
 Signature Summary
 -----------------
@@ -205,7 +166,7 @@ See Also
 -------------------------------------------------------------------------------
 
 * https://en.wikipedia.org/wiki/Line_graph
-* The queries use the :ref:`sampledata` network.
+* The queries use the :doc:`sampledata` network.
 
 .. rubric:: Indices and tables
 

doc/queries/CMakeLists.txt

@@ -44,6 +44,7 @@ SET(LOCAL_FILES
     trsp_notes_v2.5.0.queries
     oneDepotWrapper.queries
     doc-gsoc_vrppdtw.queries
+    doc-pgr_lineGraph.queries
     )
 
 foreach (f ${LOCAL_FILES})
@@ -52,4 +53,3 @@ foreach (f ${LOCAL_FILES})
 endforeach()
 
 set(PgRouting_DOC_FILES ${PgRouting_DOC_FILES} ${LOCAL_DOC_FILES} PARENT_SCOPE)
-

doc/src/proposed.rst

@@ -153,15 +153,14 @@ Experimental and Proposed functions
   pgr_gsoc_vrppdtw
   pgr_vrpOneDepot
 
+.. rubric:: Graph Transformation
 
-.. rubric:: rewrite of pgr_TRSP
-
-- :ref:`pgr_dijkstraTRSP`
+:doc:`pgr_lineGraph`
 
 .. toctree::
   :hidden:
 
-  pgr_dijkstraTRSP
+  pgr_lineGraph
 
 
 ..

include/dijkstraTRSP/pgr_dijkstraTRSP.hpp

@@ -98,6 +98,7 @@ Pgr_dijkstraTRSP< G >::dijkstraTRSP(
     if (curr_result_path.size() or graph.m_gType == UNDIRECTED)
         return curr_result_path;
 
+#if 0
     pgrouting::LinearDirectedGraph line(DIRECTED);
     line.insert_vertices(edges);
     auto line_graph_edges = line.transform(graph);
@@ -109,6 +110,8 @@ Pgr_dijkstraTRSP< G >::dijkstraTRSP(
 
     line.create_virtual_vertices();
     log << line << "\n";
+#endif
+
     return curr_result_path;
 }