Add (passing) test_to_dense2 to test to_dense when the tensor has a virtual dimension that uses a physical dimension multiple times.

Author: ValerianRey

tests/unit/sparse/test_diagonal_sparse_tensor.py

@@ -2,7 +2,7 @@
 from pytest import mark
 from torch.ops import aten  # type: ignore
 from torch.testing import assert_close
-from utils.tensors import randn_, zeros_
+from utils.tensors import randn_, tensor_, zeros_
 
 from torchjd.sparse._diagonal_sparse_tensor import (
     _IN_PLACE_POINTWISE_FUNCTIONS,
@@ -28,6 +28,14 @@ def test_to_dense():
             assert c[i, j, j, i] == a[i, j]
 
 
+def test_to_dense2():
+    a = tensor_([1.0, 2.0, 3.0])
+    b = DiagonalSparseTensor(a, [[0, 0]])
+    c = b.to_dense()
+    expected = tensor_([1.0, 0.0, 0.0, 0.0, 2.0, 0.0, 0.0, 0.0, 3.0])
+    assert torch.all(torch.eq(c, expected))
+
+
 @mark.parametrize(
     ["a_pshape", "a_v_to_ps", "b_pshape", "b_v_to_ps", "a_indices", "b_indices", "output_indices"],
     [