VectorStateFn¶

class VectorStateFn(primitive=None, coeff=1.0, is_measurement=False)[source]¶

A class for state functions and measurements which are defined in vector representation, and stored using Terra’s Statevector class.

Parameters

primitive (Union[list, ndarray, Statevector, None]) – The Statevector, NumPy array, or list, which defines the behavior of the underlying function.
coeff (Union[int, float, complex, ParameterExpression]) – A coefficient multiplying the state function.
is_measurement (bool) – Whether the StateFn is a measurement operator

Attributes

`VectorStateFn.coeff`	A coefficient by which the state function is multiplied.
`VectorStateFn.is_measurement`	Whether the StateFn object is a measurement Operator.
`VectorStateFn.num_qubits`	The number of qubits over which the Operator is defined.
`VectorStateFn.primitive`	The primitive which defines the behavior of the underlying State function.

Methods

`VectorStateFn.__mul__`(other)	Overload `*` for Operator scalar multiplication.
`VectorStateFn.add`(other)	Return Operator addition of self and other, overloaded by `+`.
`VectorStateFn.adjoint`()	Return a new Operator equal to the Operator’s adjoint (conjugate transpose), overloaded by `~`.
`VectorStateFn.assign_parameters`(param_dict)	Binds scalar values to any Terra `Parameters` in the coefficients or primitives of the Operator, or substitutes one `Parameter` for another.
`VectorStateFn.bind_parameters`(param_dict)	Same as assign_parameters, but maintained for consistency with QuantumCircuit in Terra (which has both assign_parameters and bind_parameters).
`VectorStateFn.compose`(other)	Composition (Linear algebra-style: A@B(x) = A(B(x))) is not well defined for states in the binary function model, but is well defined for measurements.
`VectorStateFn.equals`(other)	Evaluate Equality between Operators, overloaded by `==`.
`VectorStateFn.eval`([front])	Evaluate the Operator’s underlying function, either on a binary string or another Operator.
`VectorStateFn.mul`(scalar)	Returns the scalar multiplication of the Operator, overloaded by `*`, including support for Terra’s `Parameters`, which can be bound to values later (via `bind_parameters`).
`VectorStateFn.neg`()	Return the Operator’s negation, effectively just multiplying by -1.0, overloaded by `-`.
`VectorStateFn.power`(exponent)	Compose with Self Multiple Times, undefined for StateFns.
`VectorStateFn.primitive_strings`()	Return a set of strings describing the primitives contained in the Operator.
`VectorStateFn.reduce`()	Try collapsing the Operator structure, usually after some type of conversion, e.g.
`VectorStateFn.sample`([shots, massive, …])	Sample the state function as a normalized probability distribution.
`VectorStateFn.tensor`(other)	Return tensor product between self and other, overloaded by `^`.
`VectorStateFn.tensorpower`(other)	Return tensor product with self multiple times, overloaded by `^`.
`VectorStateFn.to_circuit_op`()	Return `StateFnCircuit` corresponding to this StateFn.
`VectorStateFn.to_density_matrix`([massive])	Return matrix representing product of StateFn evaluated on pairs of basis states.
`VectorStateFn.to_legacy_op`([massive])	Attempt to return the Legacy Operator representation of the Operator.
`VectorStateFn.to_matrix`([massive])	Return NumPy representation of the Operator.
`VectorStateFn.to_matrix_op`([massive])	Return a `VectorStateFn` for this `StateFn`.
`VectorStateFn.traverse`(convert_fn[, coeff])	Apply the convert_fn to the internal primitive if the primitive is an Operator (as in the case of `OperatorStateFn`).
`VectorStateFn.__mul__`(other)	Overload `*` for Operator scalar multiplication.