Ticket #10900: trac_10900.patch

sage/graphs/base/c_graph.pyx

@@ -2885 +2885 @@
     - ``test_in`` -- boolean; whether we want to consider the in-neighbors of
       the graph to be traversed. For undirected graphs, we consider both
       the in- and out-neighbors.
+
+    EXAMPLE::
+
+        sage: g = graphs.PetersenGraph()
+        sage: list(g.breadth_first_search(0))
+        [0, 1, 4, 5, 2, 6, 3, 9, 7, 8]
     """
 
     cdef graph
@@ -2925 +2931 @@
         - ``ignore_direction`` -- boolean (default: ``False``). This is only
           relevant to digraphs. If ``graph`` is a digraph, ignore all
           orientations and consider the graph as undirected.
+
+        EXAMPLE::
+        
+            sage: g = graphs.PetersenGraph()
+            sage: list(g.breadth_first_search(0))
+            [0, 1, 4, 5, 2, 6, 3, 9, 7, 8]
         """
         self.graph = graph
         self.direction = direction
@@ -2946 +2958 @@
     def __iter__(self):
         r"""
         Return an iterator object over a traversal of a graph.
+
+        EXAMPLE::
+        
+            sage: g = graphs.PetersenGraph()
+            sage: g.breadth_first_search(0)
+            <generator object breadth_first_search at ...
         """
         return self
 
     def __next__(self):
         r"""
         Return the next vertex in a traversal of a graph.
+
+        EXAMPLE::
+        
+            sage: g = graphs.PetersenGraph()
+            sage: g.breadth_first_search(0)
+            <generator object breadth_first_search at ...
+            sage: g.breadth_first_search(0).next()
+            0
         """
         cdef int v_int
         cdef int w_int

sage/graphs/base/dense_graph.pyx

@@ -156 +156 @@
         Memory usage is
         
         O(  (nverts + extra_vertices)^2  ).
-        
+
+        EXAMPLE::
+
+            sage: from sage.graphs.base.dense_graph import DenseGraph
+            sage: D = DenseGraph(nverts = 10, extra_vertices = 10)
         """
         if nverts == 0 and extra_vertices == 0:
             raise RuntimeError('Dense graphs must allocate space for vertices!')

sage/graphs/base/graph_backends.py

@@ -480 +480 @@
     def __init__(self):
         """
         Issue deprecation warnings for the old networkx XGraph formats
+
+        EXAMPLE::
+
+            sage: from sage.graphs.base.graph_backends import NetworkXGraphDeprecated
+            sage: NetworkXGraphDeprecated()
+            doctest:...
+            <class 'sage.graphs.base.graph_backends.NetworkXGraphDeprecated'>
         """
         import warnings
         from sage.misc.misc import deprecation
@@ -532 +539 @@
     def __init__(self):
         """
         Issue deprecation warnings for the old networkx XDiGraph formats
+
+        EXAMPLE::
+
+            sage: from sage.graphs.base.graph_backends import NetworkXDiGraphDeprecated
+            sage: NetworkXDiGraphDeprecated()
+            doctest:...
+            <class 'sage.graphs.base.graph_backends.NetworkXDiGraphDeprecated'>
         """
         import warnings
         from sage.misc.misc import deprecation
@@ -913 +927 @@
         """
         Iterate over the incoming edges incident to a sequence of vertices.
         Special case, only for internal use.
+
+        EXAMPLE::
+
+            sage: g = DiGraph(graphs.PetersenGraph(), implementation="networkx")._backend
+            sage: sorted(list(g.iterator_in_edges([0,1], True)))
+            [(0, 1, None), (1, 0, None), (2, 1, None), (4, 0, None), (5, 0, None), (6, 1, None)]
         """
         try:
             assert(not isinstance(self._nxg, (NetworkXGraphDeprecated, NetworkXDiGraphDeprecated)))
@@ -955 +975 @@
         """
         Iterate over the outbound edges incident to a sequence of vertices.
         Special case, only for internal use.
+
+        EXAMPLE::
+
+            sage: g = DiGraph(graphs.PetersenGraph(), implementation="networkx")._backend
+            sage: sorted(list(g.iterator_out_edges([0,1], True)))
+            [(0, 1, None), (0, 4, None), (0, 5, None), (1, 0, None), (1, 2, None), (1, 6, None)]
         """
         try:
             assert(not isinstance(self._nxg, (NetworkXGraphDeprecated, NetworkXDiGraphDeprecated)))

sage/graphs/base/sparse_graph.pyx

@@ -285 +285 @@
         Memory usage is roughly
         
         O(  (nverts + extra_vertices)*expected_degree + num_arcs  ).
-        
-        """
+
+        EXAMPLE::
+
+            sage: from sage.graphs.base.sparse_graph import SparseGraph
+            sage: S = SparseGraph(nverts = 10, expected_degree = 3, extra_vertices = 10)
+
+         """
         cdef int i = 1
         if nverts == 0 and extra_vertices == 0:
             raise RuntimeError('Sparse graphs must allocate space for vertices!')

sage/graphs/generic_graph.py

@@ -13302 +13302 @@
 
     def _keys_for_vertices(self):
         """
-        Returns a function mapping each vertex to a unique and hopefully readable string
+        Returns a function mapping each vertex to a unique and hopefully
+        readable string
+
+        EXAMPLE::
+
+            sage: g = graphs.Grid2dGraph(5,5)
+            sage: g._keys_for_vertices()
+            <function key at ...
         """
         from sage.graphs.dot2tex_utils import key, key_with_hash
         if len(set(key(v) for v in self)) < len(self.vertices()):

sage/graphs/generic_graph_pyx.pyx

@@ -483 +483 @@
 
         This constructor only checks there is no inconsistency in the
         input : `G` and `H` are both graphs or both digraphs.
+
+        EXAMPLE::
+
+            sage: g = graphs.PetersenGraph()
+            sage: g.subgraph_search(graphs.CycleGraph(5))
+            Subgraph of (Petersen graph): Graph on 5 vertices
         """
         if sum([G.is_directed(), H.is_directed()]) == 1:
             raise ValueError("One graph can not be directed while the other is not.")
@@ -596 +602 @@
         Cython constructor
 
         This method initializes all the C values.
+
+        EXAMPLE::
+
+            sage: g = graphs.PetersenGraph()
+            sage: g.subgraph_search(graphs.CycleGraph(5))
+            Subgraph of (Petersen graph): Graph on 5 vertices
         """
 
         # Storing the number of vertices