qiskit-documentation/docs/api/qiskit/0.27/qiskit.transpiler.passes.St...

110 lines
5.1 KiB
Plaintext
Raw Permalink Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

---
title: StochasticSwap
description: API reference for qiskit.transpiler.passes.StochasticSwap
in_page_toc_min_heading_level: 1
python_api_type: class
python_api_name: qiskit.transpiler.passes.StochasticSwap
---
# qiskit.transpiler.passes.StochasticSwap
<Class id="qiskit.transpiler.passes.StochasticSwap" isDedicatedPage={true} github="https://github.com/qiskit/qiskit/tree/stable/0.17/qiskit/transpiler/passes/routing/stochastic_swap.py" signature="StochasticSwap(*args, **kwargs)" modifiers="class">
Map a DAGCircuit onto a coupling\_map adding swap gates.
Uses a randomized algorithm.
**Notes**
1. Measurements may occur and be followed by swaps that result in repeated measurement of the same qubit. Near-term experiments cannot implement these circuits, so some care is required when using this mapper with experimental backend targets.
2. We do not use the fact that the input state is zero to simplify the circuit.
StochasticSwap initializer.
The coupling map is a connected graph
If these are not satisfied, the behavior is undefined.
**Parameters**
* **coupling\_map** ([*CouplingMap*](qiskit.transpiler.CouplingMap "qiskit.transpiler.CouplingMap")) Directed graph representing a coupling map.
* **trials** (*int*) maximum number of iterations to attempt
* **seed** (*int*) seed for random number generator
### \_\_init\_\_
<Function id="qiskit.transpiler.passes.StochasticSwap.__init__" signature="__init__(coupling_map, trials=20, seed=None)">
StochasticSwap initializer.
The coupling map is a connected graph
If these are not satisfied, the behavior is undefined.
**Parameters**
* **coupling\_map** ([*CouplingMap*](qiskit.transpiler.CouplingMap "qiskit.transpiler.CouplingMap")) Directed graph representing a coupling map.
* **trials** (*int*) maximum number of iterations to attempt
* **seed** (*int*) seed for random number generator
</Function>
## Methods
| | |
| -------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------- |
| [`__init__`](#qiskit.transpiler.passes.StochasticSwap.__init__ "qiskit.transpiler.passes.StochasticSwap.__init__")(coupling\_map\[, trials, seed]) | StochasticSwap initializer. |
| [`name`](#qiskit.transpiler.passes.StochasticSwap.name "qiskit.transpiler.passes.StochasticSwap.name")() | Return the name of the pass. |
| [`run`](#qiskit.transpiler.passes.StochasticSwap.run "qiskit.transpiler.passes.StochasticSwap.run")(dag) | Run the StochasticSwap pass on dag. |
## Attributes
| | |
| ------------------------------------------------------------------------------------------------------------------------------------------------------------ | ------------------------------------------- |
| [`is_analysis_pass`](#qiskit.transpiler.passes.StochasticSwap.is_analysis_pass "qiskit.transpiler.passes.StochasticSwap.is_analysis_pass") | Check if the pass is an analysis pass. |
| [`is_transformation_pass`](#qiskit.transpiler.passes.StochasticSwap.is_transformation_pass "qiskit.transpiler.passes.StochasticSwap.is_transformation_pass") | Check if the pass is a transformation pass. |
### is\_analysis\_pass
<Attribute id="qiskit.transpiler.passes.StochasticSwap.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.
</Attribute>
### is\_transformation\_pass
<Attribute id="qiskit.transpiler.passes.StochasticSwap.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).
</Attribute>
### name
<Function id="qiskit.transpiler.passes.StochasticSwap.name" signature="name()">
Return the name of the pass.
</Function>
### run
<Function id="qiskit.transpiler.passes.StochasticSwap.run" signature="run(dag)">
Run the StochasticSwap pass on dag.
**Parameters**
**dag** ([*DAGCircuit*](qiskit.dagcircuit.DAGCircuit "qiskit.dagcircuit.DAGCircuit")) DAG to map.
**Returns**
A mapped DAG.
**Return type**
[DAGCircuit](qiskit.dagcircuit.DAGCircuit "qiskit.dagcircuit.DAGCircuit")
**Raises**
* [**TranspilerError**](qiskit.transpiler.TranspilerError "qiskit.transpiler.TranspilerError") if the coupling map or the layout are not
* **compatible with the DAG**
</Function>
</Class>