removed undirected call to pytorch geometric

torch_cluster/sample.py

 import torch
-from torch_geometric.utils import to_undirected
 
 from sample_cuda import farthest_point_sampling, query_radius, query_knn
 
@@ -62,8 +61,7 @@ def radius_query_edges(batch,
                        query_pos,
                        radius,
                        max_num_neighbors=128,
-                       include_self=True,
-                       undirected=False):
+                       include_self=True):
     if not pos.is_cuda:
         raise NotImplementedError
     assert pos.is_cuda and batch.is_cuda
@@ -91,19 +89,13 @@ def radius_query_edges(batch,
         return col
 
     edge_index = torch.stack([row, col], dim=0)
-    if undirected:
-        return to_undirected(edge_index, query_pos.size(0))
     return edge_index
 
 
-def radius_graph(batch,
-                 pos,
-                 radius,
-                 max_num_neighbors=128,
-                 include_self=False,
-                 undirected=False):
+def radius_graph(batch, pos, radius, max_num_neighbors=128,
+                 include_self=False):
     return radius_query_edges(batch, pos, batch, pos, radius,
-                              max_num_neighbors, include_self, undirected)
+                              max_num_neighbors, include_self)
 
 
 def knn_query_edges(batch,
@@ -111,8 +103,7 @@ def knn_query_edges(batch,
                     query_batch,
                     query_pos,
                     num_neighbors,
-                    include_self=True,
-                    undirected=False):
+                    include_self=True):
     if not pos.is_cuda:
         raise NotImplementedError
     assert pos.is_cuda and batch.is_cuda
@@ -140,11 +131,8 @@ def knn_query_edges(batch,
     col = view[view != -1]
 
     edge_index = torch.stack([row, col], dim=0)
-    if undirected:
-        return to_undirected(edge_index, query_pos.size(0))
     return edge_index
 
 
-def knn_graph(batch, pos, num_neighbors, include_self=False, undirected=False):
-    return knn_query_edges(batch, pos, batch, pos, num_neighbors, include_self,
-                           undirected)
+def knn_graph(batch, pos, num_neighbors, include_self=False):
+    return knn_query_edges(batch, pos, batch, pos, num_neighbors, include_self)