Merge pull request #182 from jGaboardi/nearest_tree_update

Nearest tree update
pysal · Dec 3, 2018 · 8ea174c · 8ea174c
2 parents 1c91b9f + 6ed076b
commit 8ea174c
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Showing 3 changed files with 35 additions and 3 deletions.
diff --git a/spaghetti/network.py b/spaghetti/network.py
@@ -1120,7 +1120,13 @@ def allneighbordistances(self, sourcepattern, destpattern=None,
         
         tree_nearest : dict
             Nearest network node to point pattern vertex shortest
-            path lookup.
+            path lookup. The values of the dictionary are a ``tuple``
+            of the nearest source vertex and the near destination
+            vertex to query the lookup tree. If two observations are
+            snapped to the same network arc a flag of -.1 is set for
+            both the source and destination network vertex
+            indicating the same arc is used while also raising an
+            ``IndexError``` when rebuilding the path.
         
         Examples
         --------
@@ -1218,12 +1224,18 @@ def allneighbordistances(self, sourcepattern, destpattern=None,
                 dest1, dest2 = dest_vertices[p2]
                 set2 = set(dest_vertices[p2])
 
-                if set1 == set2:  # same arc
+                # when the observations are snapped to the same arc
+                if set1 == set2:
                     x1, y1 = sourcepattern.snapped_coordinates[p1]
                     x2, y2 = destpattern.snapped_coordinates[p2]
+
                     computed_length = util.compute_length((x1, y1),
                                                           (x2, y2))
                     nearest[p1, p2] = computed_length
+                    # set the nearest network vertices to a flag of -.1
+                    # indicating the same arc is used while also raising
+                    # and indexing error when rebuilding the path
+                    tree_nearest[p1, p2] = (-.1, -.1)
 
                 else:
                     ddist1, ddist2 = dst_d2n[p2].values()

diff --git a/spaghetti/tests/test_network.py b/spaghetti/tests/test_network.py
@@ -223,7 +223,17 @@ def test_all_neighbor_distances(self):
         self.assertEqual(observed.all(), known.all())
         del self.ntw.alldistances
         del self.ntw.distancematrix
-
+
+        matrix5, tree = self.ntw.allneighbordistances(self.pp2_str,
+                                                      gen_tree=True)
+        known_mtx_val = 1484112.694526529
+        known_tree_val = (-0.1, -0.1)
+
+        self.assertAlmostEqual(np.nansum(matrix5[0]), known_mtx_val, places=4)
+        self.assertEqual(tree[(18, 19)], known_tree_val)
+        del self.ntw.alldistances
+        del self.ntw.distancematrix
+
     def test_all_neighbor_distances_multiproccessing(self):
         matrix1, tree = self.ntw.allneighbordistances(self.pp1_str,
                                                       fill_diagonal=0.,

diff --git a/spaghetti/tests/test_network_api.py b/spaghetti/tests/test_network_api.py
@@ -222,6 +222,16 @@ def test_all_neighbor_distances(self):
         self.assertEqual(observed.all(), known.all())
         del self.ntw.alldistances
         del self.ntw.distancematrix
+
+        matrix5, tree = self.ntw.allneighbordistances(self.pp2_str,
+                                                      gen_tree=True)
+        known_mtx_val = 1484112.694526529
+        known_tree_val = (-0.1, -0.1)
+
+        self.assertAlmostEqual(np.nansum(matrix5[0]), known_mtx_val, places=4)
+        self.assertEqual(tree[(18, 19)], known_tree_val)
+        del self.ntw.alldistances
+        del self.ntw.distancematrix
 
     def test_all_neighbor_distances_multiproccessing(self):
         matrix1, tree = self.ntw.allneighbordistances(self.pp1_str,