Ticket #6813: worldmap.patch

sage/graphs/graph_generators.py

@@ -105 +105 @@
         - DegreeSequenceConfigurationModel
         - DegreeSequenceTree
         - DegreeSequenceExpected
+    Oddities :
+        - WorldMap
         
 
 AUTHORS:
@@ -128 +130 @@
   graphs with a given degree sequence, random directed graphs
 
 - Robert Miller (2007-10-24): Isomorph free exhaustive generation
+
+- Nathann Cohen (2009-08-12): WorldMap
 """
 
 ################################################################################
@@ -219 +223 @@
                     - DegreeSequenceConfigurationModel
                     - DegreeSequenceTree
                     - DegreeSequenceExpected
-            
+                Oddities :
+                    - WorldMap            
     
     ORDERLY GENERATION: graphs(vertices, property=lambda x: True,
     augment='edges', size=None)
@@ -2953 +2958 @@
         import networkx
         return graph.Graph(networkx.random_shell_graph(constructor, seed))
 
+    def WorldMap(self):
+        """
+        Returns the Graph of all the countries, in which two countries are adjacent
+        in the graph if they have a common boundary.
+
+        This graph has been built from the data available
+        in The CIA World Factbook [CIAWorldFactbook09]_ (2009-08-21).
+
+        The returned graph ``G`` has a member ``G.gps_coordinates`` 
+        equal to a dictionary containing the GPS coordinates
+        of each country's capital city.
+
+        EXAMPLE::
+        
+            sage: g=graphs.WorldMap()
+            sage: g.has_edge("France","Italy")
+            True
+        
+        REFERENCE:
+        
+        .. [CIAWorldFactbook09]_ CIA Factbook 09
+        https://www.cia.gov/library/publications/the-world-factbook/
+        """
+
+        from sage.structure.sage_object import load
+        from sage.misc.misc import SAGE_DATA
+        return load(SAGE_DATA+"graphs/graph_world.sobj")
+
 ################################################################################
 #   Graphs with a given degree sequence
 ################################################################################