Add a regression test for FlagserPersistence

gtda/homology/tests/test_simplicial.py

@@ -349,7 +349,7 @@ def test_fp_transform_undirected(X, max_edge_weight, infinity_values):
     # same as the one of VietorisRipsPersistence
     X_exp = X_vrp_exp.copy()
 
-    # In that case, subdiagrams of dimension 1 is empty
+    # In that case, the subdiagram of dimension 1 is empty
     if max_edge_weight == 0.6:
         X_exp[0, -1, :] = [0., 0., 1.]
 
@@ -359,6 +359,17 @@ def test_fp_transform_undirected(X, max_edge_weight, infinity_values):
     assert_almost_equal(fp.fit_transform(X), X_exp)
 
 
+@pytest.mark.parametrize('delta', range(1, 4))
+def test_fp_transform_high_hom_dim(delta):
+    """Test that if the maximum homology dimension is greater than or equal to
+    the number of points, we do not produce errors."""
+    n_points = 3
+    X = X_dist[:, :n_points, :n_points]
+    fp = FlagserPersistence(homology_dimensions=list(range(n_points + delta)))
+    assert_almost_equal(fp.fit_transform(X)[0, -1],
+                        np.array([0., 0., n_points + delta - 1], dtype=float))
+
+
 @pytest.mark.parametrize('X', [X_dist, X_dist_list, X_dist_sparse])
 @pytest.mark.parametrize('hom_dims', [None, (0,), (1,), (0, 1)])
 def test_fp_fit_transform_plot(X, hom_dims):