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| from sympy.tensor.functions import TensorProduct | |
| from sympy.matrices.dense import Matrix | |
| from sympy.matrices.expressions.matexpr import MatrixSymbol | |
| from sympy.tensor.array import Array | |
| from sympy.abc import x, y, z | |
| from sympy.abc import i, j, k, l | |
| A = MatrixSymbol("A", 3, 3) | |
| B = MatrixSymbol("B", 3, 3) | |
| C = MatrixSymbol("C", 3, 3) | |
| def test_TensorProduct_construction(): | |
| assert TensorProduct(3, 4) == 12 | |
| assert isinstance(TensorProduct(A, A), TensorProduct) | |
| expr = TensorProduct(TensorProduct(x, y), z) | |
| assert expr == x*y*z | |
| expr = TensorProduct(TensorProduct(A, B), C) | |
| assert expr == TensorProduct(A, B, C) | |
| expr = TensorProduct(Matrix.eye(2), Array([[0, -1], [1, 0]])) | |
| assert expr == Array([ | |
| [ | |
| [[0, -1], [1, 0]], | |
| [[0, 0], [0, 0]] | |
| ], | |
| [ | |
| [[0, 0], [0, 0]], | |
| [[0, -1], [1, 0]] | |
| ] | |
| ]) | |
| def test_TensorProduct_shape(): | |
| expr = TensorProduct(3, 4, evaluate=False) | |
| assert expr.shape == () | |
| assert expr.rank() == 0 | |
| expr = TensorProduct(Array([1, 2]), Array([x, y]), evaluate=False) | |
| assert expr.shape == (2, 2) | |
| assert expr.rank() == 2 | |
| expr = TensorProduct(expr, expr, evaluate=False) | |
| assert expr.shape == (2, 2, 2, 2) | |
| assert expr.rank() == 4 | |
| expr = TensorProduct(Matrix.eye(2), Array([[0, -1], [1, 0]]), evaluate=False) | |
| assert expr.shape == (2, 2, 2, 2) | |
| assert expr.rank() == 4 | |
| def test_TensorProduct_getitem(): | |
| expr = TensorProduct(A, B) | |
| assert expr[i, j, k, l] == A[i, j]*B[k, l] | |