cirq.ProjectorString

Mapping of cirq.Qid to measurement values (with a coefficient) representing a projector.

cirq.ProjectorString(
    projector_dict: dict[cirq.Qid, int], coefficient: complex = 1
)

Args
`projector_dict`	A python dictionary mapping from cirq.Qid to integers. A key value pair represents the desired computational basis state for that qubit.
`coefficient`	Initial scalar coefficient. Defaults to 1.

Attributes
`coefficient`
`projector_dict`

Attributes

coefficient

projector_dict

expectation_from_density_matrix(
    state: np.ndarray, qid_map: Mapping[cirq.Qid, int]
) -> complex

Expectation of the projection from a density matrix.

Computes the expectation value of this ProjectorString on the provided state.

Args
`state`	An array representing a valid density matrix.
`qid_map`	A map from all qubits used in this ProjectorString to the indices of the qubits that `state_vector` is defined over.

Returns
The expectation value of the input state.

expectation_from_state_vector(
    state_vector: np.ndarray, qid_map: Mapping[cirq.Qid, int]
) -> complex

Expectation of the projection from a state vector.

Computes the expectation value of this ProjectorString on the provided state vector.

Args
`state_vector`	An array representing a valid state vector.
`qid_map`	A map from all qubits used in this ProjectorString to the indices of the qubits that `state_vector` is defined over.

Returns
The expectation value of the input state.

matrix(
    projector_qids: (Iterable[cirq.Qid] | None) = None
) -> csr_matrix

Returns the matrix of self in computational basis of qubits.

Args
`projector_qids`	Ordered collection of qubits that determine the subspace in which the matrix representation of the ProjectorString is to be computed. Qbits absent from self.qubits are acted on by the identity. Defaults to the qubits of the projector_dict.

Returns
A sparse matrix that is the projection in the specified basis.

__eq__(
    other: _SupportsValueEquality
) -> bool

__ne__(
    other: _SupportsValueEquality
) -> bool