extend warning to other adjacency_matrix() calls (#904)

python/dgl/graph.py

@@ -3073,7 +3073,7 @@ class DGLGraph(DGLBaseGraph):
             transpose = False
         return self._graph.adjacency_matrix_scipy(transpose, fmt, return_edge_ids)
 
-    def adjacency_matrix(self, transpose=False, ctx=F.cpu()):
+    def adjacency_matrix(self, transpose=None, ctx=F.cpu()):
         """Return the adjacency matrix representation of this graph.
 
         By default, a row of returned adjacency matrix represents the

python/dgl/heterograph.py

@@ -1385,7 +1385,7 @@ class DGLHeteroGraph(object):
         hg = DGLHeteroGraph(hgidx, induced_ntypes, induced_etypes, node_frames, edge_frames)
         return hg
 
-    def adjacency_matrix(self, transpose=False, ctx=F.cpu(), scipy_fmt=None, etype=None):
+    def adjacency_matrix(self, transpose=None, ctx=F.cpu(), scipy_fmt=None, etype=None):
         """Return the adjacency matrix of edges of the given edge type.
 
         By default, a row of returned adjacency matrix represents the