1 files changed, 59 insertions, 0 deletions
diff --git a/src/python/test/test_betti_curve_representations.py b/src/python/test/test_betti_curve_representations.py
new file mode 100755
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+++ b/src/python/test/test_betti_curve_representations.py
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+import numpy as np
+import scipy.interpolate
+import pytest
+
+from gudhi.representations.vector_methods import BettiCurve
+
+def test_betti_curve_is_irregular_betti_curve_followed_by_interpolation():
+    m = 10
+    n = 1000
+    pinf = 0.05
+    pzero = 0.05
+    res = 100
+    
+    pds = []
+    for i in range(0, m):
+        pd = np.zeros((n, 2))
+        pd[:, 0] = np.random.uniform(0, 10, n)
+        pd[:, 1] = np.random.uniform(pd[:, 0], 10, n)
+        pd[np.random.uniform(0, 1, n) < pzero, 0] = 0
+        pd[np.random.uniform(0, 1, n) < pinf, 1] = np.inf
+        pds.append(pd)
+    
+    bc = BettiCurve(resolution=None, predefined_grid=None)
+    bc.fit(pds)
+    bettis = bc.transform(pds)
+
+    bc2 = BettiCurve(resolution=None, predefined_grid=None)
+    bettis2 = bc2.fit_transform(pds)
+    assert((bc2.grid_ == bc.grid_).all())
+    assert((bettis2 == bettis).all())
+
+    for i in range(0, m):
+        grid = np.linspace(pds[i][np.isfinite(pds[i])].min(), pds[i][np.isfinite(pds[i])].max() + 1, res)
+        bc_gridded = BettiCurve(predefined_grid=grid)
+        bc_gridded.fit([])
+        bettis_gridded = bc_gridded(pds[i])
+
+        interp = scipy.interpolate.interp1d(bc.grid_, bettis[i, :], kind="previous", fill_value="extrapolate")
+        bettis_interp = np.array(interp(grid), dtype=int)
+        assert((bettis_interp == bettis_gridded).all())
+
+
+def test_empty_with_predefined_grid():
+    random_grid = np.sort(np.random.uniform(0, 1, 100))
+    bc = BettiCurve(predefined_grid=random_grid)
+    bettis = bc.fit_transform([])
+    assert((bc.grid_ == random_grid).all())
+    assert((bettis == 0).all())
+
+    
+def test_empty():
+    bc = BettiCurve(resolution=None, predefined_grid=None)
+    bettis = bc.fit_transform([])
+    assert(bc.grid_ == [-np.inf])
+    assert((bettis == 0).all())
+
+def test_wrong_value_of_predefined_grid():
+    with pytest.raises(ValueError):
+        BettiCurve(predefined_grid=[1, 2, 3])