cirq.unitary_eig

Gives the guaranteed unitary eigendecomposition of a normal matrix.

cirq.unitary_eig(
    matrix: np.ndarray, check_preconditions: bool = True, atol: float = 1e-08
) -> Tuple[np.ndarray, np.ndarray]

All hermitian and unitary matrices are normal matrices. This method was introduced as for certain classes of unitary matrices (where the eigenvalues are close to each other) the eigenvectors returned by numpy.linalg.eig are not guaranteed to be orthogonal. For more information, see https://github.com/numpy/numpy/issues/15461

Args
`matrix`	A normal matrix. If not normal, this method is not guaranteed to return correct eigenvalues. A normal matrix is one where \(A A^\dagger = A^\dagger A\).
`check_preconditions`	When true and matrix is not unitary, a `ValueError` is raised when the matrix is not normal.
`atol`	The absolute tolerance when checking whether the original matrix was unitary.

Returns
A Tuple of eigvals: The eigenvalues of `matrix`. V: The unitary matrix with the eigenvectors as columns.

Raises
`ValueError`	if the input matrix is not normal.

cirq.unitary_eig

Args

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