Permutation.assign_parameters¶

Permutation.assign_parameters(param_dict, inplace=False)¶

Assign parameters to new parameters or values.

The keys of the parameter dictionary must be Parameter instances in the current circuit. The values of the dictionary can either be numeric values or new parameter objects. The values can be assigned to the current circuit object or to a copy of it.

Parameters

param_dict (dict) – A dictionary specifying the mapping from current_parameter to new_parameter, where new_parameter can be a new parameter object or a numeric value.
inplace (bool) – If False, a copy of the circuit with the bound parameters is returned. If True the circuit instance itself is modified.

Raises

CircuitError – If param_dict contains parameters not present in the circuit

Returns

A copy of the circuit with bound parameters, if: inplace is True, otherwise None.

Return type

optional(QuantumCircuit)

Examples

>>> from qiskit.circuit import QuantumCircuit, Parameter
>>> circuit = QuantumCircuit(2)
>>> params = [Parameter('A'), Parameter('B'), Parameter('C')]
>>> circuit.ry(params[0], 0)
>>> circuit.crx(params[1], 0, 1)
>>> circuit.draw()
        ┌───────┐
q_0: |0>┤ Ry(A) ├────■────
        └───────┘┌───┴───┐
q_1: |0>─────────┤ Rx(B) ├
                 └───────┘
>>> circuit.assign_parameters({params[0]: params[2]}, inplace=True)
>>> circuit.draw()
        ┌───────┐
q_0: |0>┤ Ry(C) ├────■────
        └───────┘┌───┴───┐
q_1: |0>─────────┤ Rx(B) ├
                 └───────┘
>>> bound_circuit = circuit.assign_parameters({params[1]: 1, params[2]: 2})
>>> bound_circuit.draw()
        ┌───────┐
q_0: |0>┤ Ry(2) ├────■────
        └───────┘┌───┴───┐
q_1: |0>─────────┤ Rx(1) ├
                 └───────┘
>>> bound_circuit.parameters  # this one has no free parameters anymore
set()
>>> circuit.parameters  # the original one is still parameterized
{Parameter(A), Parameter(C)}