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class Optimize1qGatesDecomposition(*args, **kwargs)

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Bases: qiskit.transpiler.basepasses.TransformationPass

Optimize chains of single-qubit gates by combining them into a single gate.

The decision to replace the original chain with a new resynthesis depends on:

  • whether the original chain was out of basis: replace
  • whether the original chain was in basis but resynthesis is lower error: replace
  • whether the original chain contains a pulse gate: do not replace
  • whether the original chain amounts to identity: replace with null

Error is computed as a multiplication of the errors of individual gates on that qubit.

Optimize1qGatesDecomposition initializer.


  • basis (list[str]) – Basis gates to consider, e.g. [‘u3’, ‘cx’]. For the effects of this pass, the basis is the set intersection between the basis parameter and the Euler basis. Ignored if target is also specified.
  • target (Optional[Target]) – The Target object corresponding to the compilation target. When specified, any argument specified for basis_gates is ignored.



Return the name of the pass.


Run the Optimize1qGatesDecomposition pass on dag.


dag (DAGCircuit) – the DAG to be optimized.


the optimized DAG.

Return type




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.


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).

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