test sinkhorn with empty marginals

Author: rflamary

test/test_bregman.py

@@ -23,6 +23,33 @@ def test_sinkhorn():
     assert np.allclose(u, G.sum(0), atol=1e-05)  # cf convergence sinkhorn
 
 
+def test_sinkhorn_empty():
+    # test sinkhorn
+    n = 100
+    np.random.seed(0)
+
+    x = np.random.randn(n, 2)
+    u = ot.utils.unif(n)
+
+    M = ot.dist(x, x)
+
+    G = ot.sinkhorn([], [], M, 1, stopThr=1e-10)
+    # check constratints
+    assert np.allclose(u, G.sum(1), atol=1e-05)  # cf convergence sinkhorn
+    assert np.allclose(u, G.sum(0), atol=1e-05)  # cf convergence sinkhorn
+
+    G = ot.sinkhorn([], [], M, 1, stopThr=1e-10, method='sinkhorn_stabilized')
+    # check constratints
+    assert np.allclose(u, G.sum(1), atol=1e-05)  # cf convergence sinkhorn
+    assert np.allclose(u, G.sum(0), atol=1e-05)  # cf convergence sinkhorn
+
+    G = ot.sinkhorn(
+        [], [], M, 1, stopThr=1e-10, method='sinkhorn_epsilon_scaling')
+    # check constratints
+    assert np.allclose(u, G.sum(1), atol=1e-05)  # cf convergence sinkhorn
+    assert np.allclose(u, G.sum(0), atol=1e-05)  # cf convergence sinkhorn
+
+
 def test_sinkhorn_variants():
     # test sinkhorn
     n = 100
@@ -37,7 +64,9 @@ def test_sinkhorn_variants():
     Gs = ot.sinkhorn(u, u, M, 1, method='sinkhorn_stabilized', stopThr=1e-10)
     Ges = ot.sinkhorn(
         u, u, M, 1, method='sinkhorn_epsilon_scaling', stopThr=1e-10)
+    Gerr = ot.sinkhorn(u, u, M, 1, method='do_not_exists', stopThr=1e-10)
 
-    # check constratints
+    # check values
     assert np.allclose(G0, Gs, atol=1e-05)
     assert np.allclose(G0, Ges, atol=1e-05)
+    assert np.allclose(G0, Gerr)

test/test_ot.py

@@ -40,6 +40,29 @@ def test_emd_emd2():
     assert np.allclose(w, 0)
 
 
+def test_emd_empty():
+    # test emd and emd2 for simple identity
+    n = 100
+    np.random.seed(0)
+
+    x = np.random.randn(n, 2)
+    u = ot.utils.unif(n)
+
+    M = ot.dist(x, x)
+
+    G = ot.emd([], [], M)
+
+    # check G is identity
+    assert np.allclose(G, np.eye(n) / n)
+    # check constratints
+    assert np.allclose(u, G.sum(1))  # cf convergence sinkhorn
+    assert np.allclose(u, G.sum(0))  # cf convergence sinkhorn
+
+    w = ot.emd2([], [], M)
+    # check loss=0
+    assert np.allclose(w, 0)
+
+
 def test_emd2_multi():
 
     from ot.datasets import get_1D_gauss as gauss