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class CollectLinearFunctions(*args, **kwargs)

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Bases: qiskit.transpiler.passes.optimization.collect_and_collapse.CollectAndCollapse

Collect blocks of linear gates (CXGate and SwapGate gates) and replaces them by linear functions (LinearFunction).

CollectLinearFunctions initializer.


  • do_commutative_analysis (bool) – if True, exploits commutativity relations between nodes.
  • split_blocks (bool) – if True, splits collected blocks into sub-blocks over disjoint qubit subsets.
  • min_block_size (int) – specifies the minimum number of gates in the block for the block to be collected.



Return the name of the pass.


Run the CollectLinearFunctions pass on dag. :param dag: the DAG to be optimized. :type dag: DAGCircuit


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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