CircuitStateFn¶
- class CircuitStateFn(primitive=None, coeff=1.0, is_measurement=False, from_operator=False)[source]¶
Bases:
qiskit.opflow.state_fns.state_fn.StateFn
A class for state functions and measurements which are defined by the action of a QuantumCircuit starting from |0⟩, and stored using Terra’s
QuantumCircuit
class.- Parameters
primitive (
Union
[QuantumCircuit
,Instruction
,None
]) – TheQuantumCircuit
(orInstruction
, which will be converted) which defines the behavior of the underlying function.coeff (
Union
[complex
,ParameterExpression
]) – A coefficient multiplying the state function.is_measurement (
bool
) – Whether the StateFn is a measurement operator.from_operator (
bool
) – if True the StateFn is derived from OperatorStateFn. (Default: False)
- Raises
TypeError – Unsupported primitive, or primitive has ClassicalRegisters.
Methods Defined Here
Return Operator addition of self and other, overloaded by
+
.Return a new Operator equal to the Operator's adjoint (conjugate transpose), overloaded by
~
.Binds scalar values to any Terra
Parameters
in the coefficients or primitives of the Operator, or substitutes oneParameter
for another.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.
Evaluate the Operator's underlying function, either on a binary string or another Operator.
Construct the CircuitStateFn from a dict mapping strings to probability densities.
Construct the CircuitStateFn from a vector representing the statevector.
Permute the qubits of the circuit.
Return a set of strings describing the primitives contained in the Operator.
Try collapsing the Operator structure, usually after some type of conversion, e.g.
Sample the state function as a normalized probability distribution.
Return tensor product between self and other, overloaded by
^
.Return QuantumCircuit representing StateFn
Return
StateFnCircuit
corresponding to this StateFn.Return numpy matrix of density operator, warn if more than 16 qubits to force the user to set massive=True if they want such a large matrix.
Return Instruction corresponding to primitive.
Return NumPy representation of the Operator.
Attributes
- INDENTATION = ' '¶
- coeff¶
A coefficient by which the state function is multiplied.
- Return type
Union
[complex
,ParameterExpression
]
- instance_id¶
Return the unique instance id.
- Return type
int
- is_measurement¶
Whether the StateFn object is a measurement Operator.
- Return type
bool
- num_qubits¶
- Return type
int
- parameters¶
- primitive: qiskit.circuit.quantumcircuit.QuantumCircuit¶
The primitive which defines the behavior of the underlying State function.
- settings¶
Return settings.
- Return type
Dict