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QasmSimulatorPy

qiskit.providers.basicaer.QasmSimulatorPy(configuration=None, provider=None, **fields) GitHub(opens in a new tab)

Bases: BackendV1

Python implementation of an OpenQASM 2 simulator.

Initialize a backend class

Parameters

  • configuration (BackendConfiguration) – A backend configuration object for the backend object.
  • provider (qiskit.providers.Provider) – Optionally, the provider object that this Backend comes from.
  • fields – kwargs for the values to use to override the default options.

Raises

AttributeError(opens in a new tab) – if input field not a valid options

In addition to the public abstract methods, subclasses should also implement the following private methods:

classmethod _default_options()

Return the default options

This method will return a qiskit.providers.Options subclass object that will be used for the default options. These should be the default parameters to use for the options of the backend.

Returns

A options object with

default values set

Return type

qiskit.providers.Options


Attributes

DEFAULT_CONFIGURATION

= {'backend_name': 'qasm_simulator', 'backend_version': '2.1.0', 'basis_gates': ['h', 'u', 'p', 'u1', 'u2', 'u3', 'rz', 'sx', 'x', 'cx', 'id', 'unitary'], 'conditional': True, 'coupling_map': None, 'description': 'A python simulator for qasm experiments', 'gates': [{'name': 'h', 'parameters': [], 'qasm_def': 'gate h q { U(pi/2,0,pi) q; }'}, {'name': 'p', 'parameters': ['lambda'], 'qasm_def': 'gate p(lambda) q { U(0,0,lambda) q; }'}, {'name': 'u', 'parameters': ['theta', 'phi', 'lambda'], 'qasm_def': 'gate u(theta,phi,lambda) q { U(theta,phi,lambda) q; }'}, {'name': 'u1', 'parameters': ['lambda'], 'qasm_def': 'gate u1(lambda) q { U(0,0,lambda) q; }'}, {'name': 'u2', 'parameters': ['phi', 'lambda'], 'qasm_def': 'gate u2(phi,lambda) q { U(pi/2,phi,lambda) q; }'}, {'name': 'u3', 'parameters': ['theta', 'phi', 'lambda'], 'qasm_def': 'gate u3(theta,phi,lambda) q { U(theta,phi,lambda) q; }'}, {'name': 'rz', 'parameters': ['phi'], 'qasm_def': 'gate rz(phi) q { U(0,0,phi) q; }'}, {'name': 'sx', 'parameters': [], 'qasm_def': 'gate sx(phi) q { U(pi/2,7*pi/2,pi/2) q; }'}, {'name': 'x', 'parameters': [], 'qasm_def': 'gate x q { U(pi,7*pi/2,pi/2) q; }'}, {'name': 'cx', 'parameters': [], 'qasm_def': 'gate cx c,t { CX c,t; }'}, {'name': 'id', 'parameters': [], 'qasm_def': 'gate id a { U(0,0,0) a; }'}, {'name': 'unitary', 'parameters': ['matrix'], 'qasm_def': 'unitary(matrix) q1, q2,...'}], 'local': True, 'max_shots': 0, 'memory': True, 'n_qubits': 24, 'open_pulse': False, 'simulator': True, 'url': 'https://github.com/Qiskit/qiskit-terra'}

DEFAULT_OPTIONS

= {'chop_threshold': 1e-15, 'initial_statevector': None}

MAX_QUBITS_MEMORY

= 29

SHOW_FINAL_STATE

= False

options

Return the options for the backend

The options of a backend are the dynamic parameters defining how the backend is used. These are used to control the run() method.

version

= 1


Methods

configuration

configuration()

Return the backend configuration.

Returns

the configuration for the backend.

Return type

BackendConfiguration

name

name()

Return the backend name.

Returns

the name of the backend.

Return type

str(opens in a new tab)

properties

properties()

Return the backend properties.

Returns

the configuration for the backend. If the backend does not support properties, it returns None.

Return type

BackendProperties

provider

provider()

Return the backend Provider.

Returns

the Provider responsible for the backend.

Return type

Provider

run

run(run_input, **backend_options)

Run on the backend.

Parameters

Returns

derived from BaseJob

Return type

BasicAerJob

Additional Information:

backend_options: Is a dict of options for the backend. It may contain

  • “initial_statevector”: vector_like

The “initial_statevector” option specifies a custom initial initial statevector for the simulator to be used instead of the all zero state. This size of this vector must be correct for the number of qubits in run_input parameter.

Example:

backend_options = {
    "initial_statevector": np.array([1, 0, 0, 1j]) / np.sqrt(2),
}

run_experiment

run_experiment(experiment)

Run an experiment (circuit) and return a single experiment result.

Parameters

experiment (QasmQobjExperiment) – experiment from qobj experiments list

Returns

A result dictionary which looks something like:

{
"name": name of this experiment (obtained from qobj.experiment header)
"seed": random seed used for simulation
"shots": number of shots used in the simulation
"data":
    {
    "counts": {'0x9: 5, ...},
    "memory": ['0x9', '0xF', '0x1D', ..., '0x9']
    },
"status": status string for the simulation
"success": boolean
"time_taken": simulation time of this single experiment
}

Return type

dict(opens in a new tab)

Raises

BasicAerError – if an error occurred.

set_options

set_options(**fields)

Set the options fields for the backend

This method is used to update the options of a backend. If you need to change any of the options prior to running just pass in the kwarg with the new value for the options.

Parameters

fields – The fields to update the options

Raises

AttributeError(opens in a new tab) – If the field passed in is not part of the options

status

status()

Return the backend status.

Returns

the status of the backend.

Return type

BackendStatus

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