Simplify structure of aer.noise and aer.utils modules

CHANGELOG.md

@@ -57,9 +57,19 @@ Added
 
 Changed
 -------
+- Moved the location of several functions (\#568):
+  - Moved contents of `qiskit.provider.aer.noise.errors` into the `qiskit.providers.noise` module
+  - Moved contents of `qiskit.provider.aer.noise.device` into the `qiskit.providers.noise` module.
+  - Moved contents of `qiskit.provider.aer.noise.utils` into the `qiskit.provider.aer.utils` module.
+
+Deprecated
+----------
+- Deprecated `utils.qobj_utils` functions (\#568)
 
 Removed
 -------
+- Removed `NoiseModel.as_dict`, `QuantumError.as_dict`, `ReadoutError.as_dict`, and 
+  `QuantumError.kron` methods that were deprecated in 0.3 (\#568).
 
 Fixed
 -----

README.md

@@ -26,42 +26,41 @@ $ python
 ```
 
 ```python
-from qiskit import QuantumRegister, ClassicalRegister, QuantumCircuit, execute
+from qiskit import QuantumCircuit, execute
 from qiskit import Aer, IBMQ  # import the Aer and IBMQ providers
-from qiskit.providers.aer import noise  # import Aer noise models
+from qiskit.providers.aer import noise  # import Aer noise module
 
 # Choose a real device to simulate
 provider = IBMQ.load_account()
-device = provider.get_backend('ibmq_16_melbourne')
+device = provider.get_backend('ibmq_vigo')
 properties = device.properties()
 coupling_map = device.configuration().coupling_map
 
 # Generate an Aer noise model for device
-noise_model = noise.device.basic_device_noise_model(properties)
+noise_model = noise.basic_device_noise_model(properties)
 basis_gates = noise_model.basis_gates
 
-# Generate a quantum circuit
-q = QuantumRegister(2)
-c = ClassicalRegister(2)
-qc = QuantumCircuit(q, c)
-
-qc.h(q[0])
-qc.cx(q[0], q[1])
-qc.measure(q, c)
+# Generate 3-qubit GHZ state
+num_qubits = 3
+circ = QuantumCircuit(3, 3)
+circ.h(0)
+circ.cx(0, 1)
+circ.cx(1, 2)
+circ.measure([0, 1, 2], [0, 1 ,2])
 
 # Perform noisy simulation
 backend = Aer.get_backend('qasm_simulator')
-job_sim = execute(qc, backend,
-                  coupling_map=coupling_map,
-                  noise_model=noise_model,
-                  basis_gates=basis_gates)
-sim_result = job_sim.result()
+job = execute(circ, backend,
+              coupling_map=coupling_map,
+              noise_model=noise_model,
+              basis_gates=basis_gates)
+result = job.result()
 
-print(sim_result.get_counts(qc))
+print(result.get_counts(0))
 ```
 
 ```python
-{'11': 412, '00': 379, '10': 117, '01': 116}
+{'000': 495, '001': 18, '010': 8, '011': 18, '100': 2, '101': 14, '110': 28, '111': 441}
 ```
 
 

docs/apidocs/aer_utils.rst

@@ -0,0 +1,6 @@
+.. _aer-utils:
+
+.. automodule:: qiskit.providers.aer.utils
+    :no-members:
+    :no-inherited-members:
+    :no-special-members:

docs/apidocs/qiskit_aer.rst

@@ -9,8 +9,6 @@ API Documentation
 
     aer_provider
     aer_extensions
-    aer_pulse
     aer_noise
-    aer_noise_errors
-    aer_noise_device
-    aer_noise_utils
+    aer_pulse
+    aer_utils

qiskit/providers/aer/backends/pulse_simulator.py

@@ -98,8 +98,8 @@ class PulseSimulator(AerBackend):
         'conditional': True,
         'open_pulse': True,
         'memory': False,
-        'max_shots': 10**6,
-        'description': 'A pulse-based Hamiltonian simulator',
+        'max_shots': int(1e6),
+        'description': 'A pulse-based Hamiltonian simulator for Pulse Qobj files',
         'gates': [],
         'basis_gates': []
     }

qiskit/providers/aer/backends/qasm_simulator.py

@@ -207,8 +207,8 @@ class QasmSimulator(AerBackend):
         'conditional': True,
         'open_pulse': False,
         'memory': True,
-        'max_shots': 100000,
-        'description': 'A C++ simulator with realistic noise for qobj files',
+        'max_shots': int(1e6),
+        'description': 'A C++ simulator with realistic noise for QASM Qobj files',
         'coupling_map': None,
         'basis_gates': [
             'u1', 'u2', 'u3', 'cx', 'cz', 'id', 'x', 'y', 'z', 'h', 's', 'sdg',

qiskit/providers/aer/backends/statevector_simulator.py

@@ -80,8 +80,12 @@ class StatevectorSimulator(AerBackend):
         'conditional': True,
         'open_pulse': False,
         'memory': True,
-        'max_shots': 1,
-        'description': 'A C++ statevector simulator for qobj files',
+        'max_shots': int(1e6),  # Note that this backend will only ever
+                                # perform a single shot. This value is just
+                                # so that the default shot value for execute
+                                # will not raise an error when trying to run
+                                # a simulation
+        'description': 'A C++ statevector simulator for QASM Qobj files',
         'coupling_map': None,
         'basis_gates': [
             'u1', 'u2', 'u3', 'cx', 'cz', 'id', 'x', 'y', 'z', 'h', 's', 'sdg',

qiskit/providers/aer/backends/unitary_simulator.py

@@ -87,9 +87,12 @@ class UnitarySimulator(AerBackend):
         'conditional': False,
         'open_pulse': False,
         'memory': False,
-        'max_shots': 1,
-        'description': 'A Python simulator for computing the unitary'
-                       'matrix for experiments in qobj files',
+        'max_shots': int(1e6),  # Note that this backend will only ever
+                                # perform a single shot. This value is just
+                                # so that the default shot value for execute
+                                # will not raise an error when trying to run
+                                # a simulation
+        'description': 'A C++ unitary simulator for QASM Qobj files',
         'coupling_map': None,
         'basis_gates': [
             'u1', 'u2', 'u3', 'cx', 'cz', 'id', 'x', 'y', 'z', 'h', 's', 'sdg',

qiskit/providers/aer/noise/__init__.py

@@ -24,38 +24,75 @@
 Classes
 =======
 
+The following are the classes used to represented noise and error terms.
+
 .. autosummary::
     :toctree: ../stubs/
 
     NoiseModel
+    QuantumError
+    ReadoutError
 
 
-Submodules
-==========
+Quantum Error Functions
+=======================
 
-Errors for Noise Models
------------------------
+The following functions can be used to generate many common types of
+:class:`QuantumError` objects for inclusion in a :class:`NoiseModel`.
 
-The :mod:`qiskit.providers.aer.noise.errors` submodule contains classes
-and functions for constructing generating errors for custom noise models.
+.. autosummary::
+    :toctree: ../stubs/
 
+    pauli_error
+    depolarizing_error
+    pauli_error
+    mixed_unitary_error
+    coherent_unitary_error
+    reset_error
+    amplitude_damping_error
+    phase_damping_error
+    phase_amplitude_damping_error
+    thermal_relaxation_error
+    kraus_error
 
-Device Noise Models
--------------------
 
-The :mod:`qiskit.providers.aer.noise.device` submodule contains functions
-for generating approximate noise models for a hardware device.
+Noise Model Functions
+=====================
 
+The following functions can be used to generate approximate noise models for
+IBMQ hardware devices based on the parameters in their backend properties.
 
-Noise Utilities
----------------
+.. autosummary::
+    :toctree: ../stubs/
 
-The :mod:`qiskit.providers.aer.noise.utils` submodule contains utilities
-for remapping and approximating noise models, and inserting noise into
-quantum circuits.
+    basic_device_noise_model
+    basic_device_readout_errors
+    basic_device_gate_errors
 """
 
+# Noise and Error classes
 from .noise_model import NoiseModel
+from .errors import QuantumError
+from .errors import ReadoutError
+
+# Error generating functions
+from .errors import kraus_error
+from .errors import mixed_unitary_error
+from .errors import coherent_unitary_error
+from .errors import pauli_error
+from .errors import depolarizing_error
+from .errors import reset_error
+from .errors import thermal_relaxation_error
+from .errors import phase_amplitude_damping_error
+from .errors import amplitude_damping_error
+from .errors import phase_damping_error
+
+# Noise model generating functions
+from .device.models import basic_device_noise_model
+from .device.models import basic_device_readout_errors
+from .device.models import basic_device_gate_errors
+
+# Submodules
 from . import errors
 from . import device
 from . import utils

qiskit/providers/aer/noise/device/__init__.py

@@ -11,59 +11,7 @@
 # that they have been altered from the originals.
 
 """
-=============================================================
-Device Noise Model (:mod:`qiskit.providers.aer.noise.device`)
-=============================================================
-
-.. currentmodule:: qiskit.providers.aer.noise.device
-
-Approximate noise models for a hardware device can be generated from the
-device properties using the functions in this module.
-
-Basic device noise model
-========================
-
-The :func:`basic_device_noise_model` function generates a noise model
-based on:
-
-* 1 and 2 qubit gate errors consisting of a
-  :func:`~qiskit.providers.aer.noise.errors.depolarizing_error` followed
-  by a :func:`~qiskit.providers.aer.noise.errors.thermal_relaxation_error`.
-
-* Single qubit :class:`~qiskit.providers.aer.noise.errors.ReadoutError` on
-  all measurements.
-
-The Error error parameters are tuned for each individual qubit based on
-the :math:`T_1`, :math:`T_2`, frequency and readout error parameters for
-each qubit, and the gate error and gate time parameters for each gate
-obtained from the device backend properties.
-
-
-Functions
-=========
-
-.. autosummary::
-    :toctree: ../stubs/
-
-    basic_device_noise_model
-    basic_device_readout_errors
-    basic_device_gate_errors
-
-
-Helper functions
-================
-
-The following helper functions can be used to extract parameters from
-a device ``BackendProperties`` object.
-
-.. autosummary::
-    :toctree: ../stubs/
-
-    parameters.gate_param_values
-    parameters.gate_error_values
-    parameters.gate_length_values
-    parameters.readout_error_values
-    parameters.thermal_relaxation_values
+Functions for building noise models from backend properties.
 """
 
 from .models import basic_device_noise_model