---
title: CollectPermutations (latest version)
description: API reference for qiskit_ibm_transpiler.ai.CollectPermutations in the latest version of qiskit-ibm-transpiler
source: https://eu-de.quantum.cloud.ibm.com/docs/en/api/qiskit-ibm-transpiler/ai-collect-permutations
---

# CollectPermutations

*class* `qiskit_ibm_transpiler.ai.CollectPermutations(do_commutative_analysis: bool = True, min_block_size: int = 4, max_block_size: int = PERMUTATION_MAX_BLOCK_SIZE, collect_from_back: bool = False, num_reps: int = 10)`

[GitHub](https://github.com/Qiskit/qiskit-ibm-transpiler/tree/stable/0.18/qiskit_ibm_transpiler/ai/collection.py#L465-L502)

Bases: `RepeatedCollectAndCollapse`

Collects blocks of SWAP circuits as Permutations.

**Parameters**

- **do\_commutative\_analysis** ([*bool*](https://docs.python.org/3/library/functions.html#bool)) – Enable or disable commutative analysis, defaults to True
- **min\_block\_size** ([*int*](https://docs.python.org/3/library/functions.html#int)*, optional*) – Set the minimum size for blocks generated during the collect permutations pass, defaults to 4.
- **max\_block\_size** ([*int*](https://docs.python.org/3/library/functions.html#int)*, optional*) – Set the maximum size for blocks generated during the collect permutations pass, defaults to 12.
- **collect\_from\_back** ([*bool*](https://docs.python.org/3/library/functions.html#bool)*, optional*) – Specify if collect blocks in reverse order or not, defaults to False.
- **num\_reps** ([*int*](https://docs.python.org/3/library/functions.html#int)*, optional*) – Specify how many times to repeat the optimization process, defaults to 10.
- **collect\_function** (*callable*) – a function that takes a DAG and returns a list of “collected” blocks of nodes
- **collapse\_function** (*callable*) – a function that takes a DAG and a list of “collected” blocks, and consolidates each block.
- **do\_commutative\_analysis** – if True, exploits commutativity relations between nodes.

## 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*](https://docs.python.org/3/library/typing.html#typing.Any)) – Qiskit IR to optimize.
- **state** ([*PassManagerState*](/docs/api/qiskit/qiskit.passmanager.PassManagerState)) – State associated with workflow execution by the pass manager itself.
- **callback** ([*Callable*](https://docs.python.org/3/library/collections.abc.html#collections.abc.Callable)) – A callback function which is caller per execution of optimization task.

**Returns**

Optimized Qiskit IR and state of the workflow.

**Return type**

[tuple](https://docs.python.org/3/library/stdtypes.html#tuple)\[[*Any*](https://docs.python.org/3/library/typing.html#typing.Any), [*PassManagerState*](/docs/api/qiskit/qiskit.passmanager.PassManagerState)]

### name

`name()`

Name of the pass.

**Return type**

[str](https://docs.python.org/3/library/stdtypes.html#str)

### run

`run(dag)`

[GitHub](https://github.com/Qiskit/qiskit-ibm-transpiler/tree/stable/0.18/qiskit_ibm_transpiler/ai/collection.py#L358-L382)

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

**Returns**

the optimized DAG.

**Return type**

DAGCircuit

### update\_status

`update_status(state, run_state)`

Update workflow status.

**Parameters**

- **state** ([*PassManagerState*](/docs/api/qiskit/qiskit.passmanager.PassManagerState)) – Pass manager state to update.
- **run\_state** (*RunState*) – Completion status of current task.

**Returns**

Updated pass manager state.

**Return type**

[*PassManagerState*](/docs/api/qiskit/qiskit.passmanager.PassManagerState)