RemoveIdentityEquivalent
class qiskit.transpiler.passes.RemoveIdentityEquivalent(*args, **kwargs)
Bases: TransformationPass
Remove gates with negligible effects.
Removes gates whose effect is close to an identity operation, up to the specified tolerance. Zero qubit gates such as GlobalPhaseGate are not considered by this pass.
For a cutoff fidelity , this pass removes gates whose average gate fidelity with respect to the identity is below . Concretely, a gate is removed if where
where is the dimension of the gate for qubits.
Initialize the transpiler pass.
Parameters
- approximation_degree – The degree to approximate for the equivalence check. This can be a floating point value between 0 and 1, or
None. If the value is 1 this does not approximate above floating point precision. For a value < 1 this is used as a scaling factor for the cutoff fidelity. If the value isNonethis approximates up to the fidelity for the gate specified intarget. - target – If
approximation_degreeis set toNoneand aTargetis provided for this field the tolerance for determining whether an operation is equivalent to identity will be set to the reported error rate in the target. Ifapproximation_degree(the default) this has no effect, ifapproximation_degree=Noneit uses the error rate specified in theTargetfor the gate being evaluated, and a numeric value other than 1 withtargetset is used as a scaling factor of the target’s error rate.
Attributes
is_analysis_pass
Check if the pass is an analysis pass.
If the pass is an AnalysisPass, that means that the pass can analyze the DAG and write the results of that analysis in the property set. Modifications on the DAG are not allowed by this kind of pass.
is_transformation_pass
Check if the pass is a transformation pass.
If the pass is a TransformationPass, that means that the pass can manipulate the DAG, but cannot modify the property set (but it can be read).
Methods
execute
execute(passmanager_ir, state, callback=None)
Execute optimization task for input Qiskit IR.
Parameters
- passmanager_ir (Any) – Qiskit IR to optimize.
- state (PassManagerState) – State associated with workflow execution by the pass manager itself.
- callback (Callable | None) – A callback function which is caller per execution of optimization task.
Returns
Optimized Qiskit IR and state of the workflow.
Return type
tuple[Any, qiskit.passmanager.compilation_status.PassManagerState]
name
run
run(dag)
Run a pass on the DAGCircuit. This is implemented by the pass developer.
Parameters
dag (DAGCircuit) – the dag on which the pass is run.
Raises
NotImplementedError – when this is left unimplemented for a pass.
Return type
update_status
update_status(state, run_state)
Update workflow status.
Parameters
- state (PassManagerState) – Pass manager state to update.
- run_state (RunState) – Completion status of current task.
Returns
Updated pass manager state.
Return type