1 files changed, 23 insertions, 0 deletions
diff --git a/test/test_ot.py b/test/test_ot.py
index 16fd510..3897397 100644
--- a/test/test_ot.py
+++ b/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