def test_entry():
B = MatrixSlice(X, (a, b), (c, d))
assert B[0, 0] == X[a, c]
assert B[k, l] == X[a + k, c + l]
pytest.raises(IndexError, lambda: MatrixSlice(X, 1, (2, 5))[1, 0])
assert X[1::2, :][1, 3] == X[1 + 2, 3]
assert X[:, 1::2][3, 1] == X[3, 1 + 2]
def test_slicing():
assert X[1:5, 2:4] == MatrixSlice(X, (1, 5), (2, 4))
assert X[1, 2:4] == MatrixSlice(X, 1, (2, 4))
assert X[1:5, :].shape == (4, X.shape[1])
assert X[:, 1:5].shape == (X.shape[0], 4)
assert X[::2, ::2].shape == (floor(n / 2), floor(m / 2))
assert X[2, :] == MatrixSlice(X, 2, (0, m))
assert X[k, :] == MatrixSlice(X, k, (0, m))
def test_indexing():
A = MatrixSymbol('A', n, m)
A[1, 2]
A[l, k]
A[l + 1, k + 1]
assert A[:] == MatrixSlice(A, (0, n, 1), (0, m, 1))
def test_indexing():
A = MatrixSymbol('A', n, m)
assert isinstance(A[1, 2], MatrixElement)
assert isinstance(A[l, k], MatrixElement)
assert isinstance(A[l+1, k+1], MatrixElement)
assert A[:] == MatrixSlice(A, (0, n, 1), (0, m, 1))
def test_inputs():
assert MatrixSlice(X, 1, (2, 5)) == MatrixSlice(X, (1, 2), (2, 5))
assert MatrixSlice(X, 1, (2, 5)).shape == (1, 3)
def test_on_diag():
assert not MatrixSlice(X, (a, b), (c, d)).on_diag
assert MatrixSlice(X, (a, b), (a, b)).on_diag
def test_shape():
B = MatrixSlice(X, (a, b), (c, d))
assert B.shape == (b - a, d - c)