Implementation of a Simplex Trie for Better Performance

test/classes/test_combinatorial_complex.py

@@ -477,6 +477,7 @@ def test_remove_nodes(self):
                 frozenset({6}): {"weight": 1},
             }
         }
+
         example.remove_nodes(HyperEdge([3]))
         assert example._complex_set.hyperedge_dict == {
             0: {frozenset({4}): {"weight": 1}, frozenset({6}): {"weight": 1}}

test/classes/test_reportviews.py

@@ -576,12 +576,9 @@ class TestReportViews_SimplexView:
 
     def test_getitem(self):
         """Test __getitem__ method of the SimplexView."""
-        assert self.simplex_view.__getitem__((1, 2)) == {
-            "is_maximal": True,
-            "membership": set(),
-        }
+        assert self.simplex_view[(1, 2)] == {}
         with pytest.raises(KeyError):
-            self.simplex_view.__getitem__([5])
+            _ = self.simplex_view[(5,)]
 
     def test_str(self):
         """Test __str__ method of the SimplexView."""
@@ -610,15 +607,12 @@ def test_repr(self):
 
     def test_getitem(self):
         """Test __getitem__ method of the NodeView."""
-        assert self.node_view.__getitem__(Simplex([1])) == {
-            "is_maximal": False,
-            "membership": {frozenset({1, 2})},
-        }
+        assert self.node_view[Simplex([1])] == {}
         with pytest.raises(KeyError):
-            self.node_view.__getitem__([1, 2])
+            _ = self.node_view[(1, 2)]
 
         # test for nodes of ColoredHyperGraph.
-        assert self.node_view_1.__getitem__([1]) == {"weight": 1}
+        assert self.node_view_1[(1,)] == {"weight": 1}
 
 
 class TestReportViews_PathView:

test/classes/test_simplex_trie.py

@@ -0,0 +1,201 @@
+"""Tests for the `simplex_trie` module."""
+
+import pytest
+
+from toponetx.classes.simplex import Simplex
+from toponetx.classes.simplex_trie import SimplexNode, SimplexTrie
+
+
+class TestSimplexNode:
+    """Tests for the `SimplexNode` class."""
+
+    def test_invalid_root(self) -> None:
+        """Test that invalid root nodes are rejected."""
+        with pytest.raises(ValueError):
+            _ = SimplexNode(label="invalid", parent=None)
+
+    def test_node_len(self) -> None:
+        """Test the length of the node."""
+        root_node: SimplexNode[int] = SimplexNode(label=None)
+        assert len(root_node) == 0
+
+        child_node: SimplexNode[int] = SimplexNode(label=1, parent=root_node)
+        assert len(child_node) == 1
+
+        grandchild_node: SimplexNode[int] = SimplexNode(label=2, parent=child_node)
+        assert len(grandchild_node) == 2
+
+    def test_node_repr(self) -> None:
+        """Test the string representation of the node."""
+        root_node = SimplexNode(label=None)
+        assert repr(root_node) == "SimplexNode(None, None)"
+
+        child_node = SimplexNode(label=1, parent=root_node)
+        assert repr(child_node) == "SimplexNode(1, SimplexNode(None, None))"
+
+    def test_simplex_property(self) -> None:
+        """Test the `simplex` property of a node."""
+        root_node = SimplexNode(label=None)
+        assert root_node.simplex is None
+
+        child_node = SimplexNode(label=1, parent=root_node)
+        assert child_node.simplex == Simplex((1,))
+
+        grandchild_node = SimplexNode(label=2, parent=child_node)
+        assert grandchild_node.simplex == Simplex((1, 2))
+
+
+class TestSimplexTrie:
+    """Tests for the `SimplexTree` class."""
+
+    def test_insert(self) -> None:
+        """Test that the internal data structures of the simplex trie are correct after insertion."""
+        trie = SimplexTrie()
+        trie.insert((1, 2, 3))
+
+        assert trie.shape == [3, 3, 1]
+
+        assert set(trie.root.children.keys()) == {1, 2, 3}
+        assert set(trie.root.children[1].children.keys()) == {2, 3}
+        assert set(trie.root.children[1].children[2].children.keys()) == {3}
+        assert set(trie.root.children[2].children.keys()) == {3}
+
+        # the label list should contain the nodes of each depth according to their label
+        label_to_simplex = {
+            1: {1: [(1,)], 2: [(2,)], 3: [(3,)]},
+            2: {2: [(1, 2)], 3: [(1, 3), (2, 3)]},
+            3: {3: [(1, 2, 3)]},
+        }
+
+        assert len(trie.label_lists) == len(label_to_simplex)
+        for depth, label_list in trie.label_lists.items():
+            assert depth in label_to_simplex
+            assert len(label_list) == len(label_to_simplex[depth])
+            for label, nodes in label_list.items():
+                assert len(nodes) == len(label_to_simplex[depth][label])
+                for node, expected in zip(
+                    nodes, label_to_simplex[depth][label], strict=True
+                ):
+                    assert node.simplex.elements == expected
+
+    def test_len(self) -> None:
+        """Test the `__len__` method of a simplex trie."""
+        trie = SimplexTrie()
+        assert len(trie) == 0
+
+        trie.insert((1, 2, 3))
+        assert len(trie) == 7
+
+    def test_getitem(self) -> None:
+        """Test the `__getitem__` method of a simplex trie."""
+        trie = SimplexTrie()
+        trie.insert((1, 2, 3))
+
+        assert trie[(1,)].simplex == Simplex((1,))
+        assert trie[(1, 2)].simplex == Simplex((1, 2))
+        assert trie[(1, 2, 3)].simplex == Simplex((1, 2, 3))
+
+        with pytest.raises(KeyError):
+            _ = trie[(0,)]
+
+    def test_iter(self) -> None:
+        """Test the iteration of the trie."""
+        trie = SimplexTrie()
+        trie.insert((1, 2, 3))
+        trie.insert((2, 3, 4))
+        trie.insert((0, 1))
+
+        # We guarantee a specific ordering of the simplices when iterating. Hence, we explicitly compare lists here.
+        assert [node.simplex.elements for node in trie] == [
+            (0,),
+            (1,),
+            (2,),
+            (3,),
+            (4,),
+            (0, 1),
+            (1, 2),
+            (1, 3),
+            (2, 3),
+            (2, 4),
+            (3, 4),
+            (1, 2, 3),
+            (2, 3, 4),
+        ]
+
+    def test_cofaces(self) -> None:
+        """Test the cofaces method."""
+        trie = SimplexTrie()
+        trie.insert((1, 2, 3))
+        trie.insert((1, 2, 4))
+
+        # no ordering is guaranteed for the cofaces method
+        assert {node.simplex.elements for node in trie.cofaces((1,))} == {
+            (1,),
+            (1, 2),
+            (1, 3),
+            (1, 4),
+            (1, 2, 3),
+            (1, 2, 4),
+        }
+        assert {node.simplex.elements for node in trie.cofaces((2,))} == {
+            (2,),
+            (1, 2),
+            (2, 3),
+            (2, 4),
+            (1, 2, 3),
+            (1, 2, 4),
+        }
+
+    def test_is_maximal(self) -> None:
+        """Test the `is_maximal` method."""
+        trie = SimplexTrie()
+        trie.insert((1, 2, 3))
+        trie.insert((1, 2, 4))
+
+        assert trie.is_maximal((1, 2, 3))
+        assert trie.is_maximal((1, 2, 4))
+        assert not trie.is_maximal((1, 2))
+        assert not trie.is_maximal((1, 3))
+        assert not trie.is_maximal((1, 4))
+        assert not trie.is_maximal((2, 3))
+
+        with pytest.raises(ValueError):
+            trie.is_maximal((5,))
+
+    def test_skeleton(self) -> None:
+        """Test the skeleton method."""
+        trie = SimplexTrie()
+        trie.insert((1, 2, 3))
+        trie.insert((1, 2, 4))
+
+        # no ordering is guaranteed for the skeleton method
+        assert {node.simplex.elements for node in trie.skeleton(0)} == {
+            (1,),
+            (2,),
+            (3,),
+            (4,),
+        }
+        assert {node.simplex.elements for node in trie.skeleton(1)} == {
+            (1, 2),
+            (1, 3),
+            (1, 4),
+            (2, 3),
+            (2, 4),
+        }
+        assert {node.simplex.elements for node in trie.skeleton(2)} == {
+            (1, 2, 3),
+            (1, 2, 4),
+        }
+
+        with pytest.raises(ValueError):
+            _ = next(trie.skeleton(-1))
+        with pytest.raises(ValueError):
+            _ = next(trie.skeleton(3))
+
+    def test_remove_simplex(self) -> None:
+        """Test the removal of simplices from the trie."""
+        trie = SimplexTrie()
+        trie.insert((1, 2, 3))
+
+        trie.remove_simplex((1, 2))
+        assert len(trie) == 5