Qiskit-aer

Changelog
========

Added
-----
- Add terra to the `Aer` requirements list (\593)
- Find muparserx system library before using distributed one (\621)
- MPS: Support multi-qubit apply matrix (\634)
- MPS: Added thresholds to loops that use parallelization (\638)
- MPS: Improvements to apply_matrix (\641)

Changed
-------
- Bump minimum required version of numpy (\594)
- Replace PyDataMem_NEW_ZEROED to PyDataMem_NEW (\578)

Fixed
-----
- Fixed bug in QuantumError compose method when composing Kraus with non-Kraus
errors (\605).
- Fix TBB compilation (\598)
- Fixed MPS expectation value when qubits are not given in ascending order (\603)
- Fix bug in QuantumError compose method (\605)
- Fix gate fusion (\606)
- Removes static numpy initialization strategy for the Pulse simulator (\609)
- Fix QuantumError sometimes casting probabilities to complex (\640)

CHANGELOG
==========

Added
-----
- Added `NoiseModel.from_backend` for building a basic device noise model for an IBMQ
backend (\569)
- Added multi-GPU enabled simulation methods to the `QasmSimulator`, `StatevectorSimulator`,
and `UnitarySimulator`. The qasm simulator has gpu version of the density matrix and
statevector methods and can be accessed using `"method": "density_matrix_gpu"` or
`"method": "statevector_gpu"` in `backend_options`. The statevector simulator gpu method
can be accessed using `"method": "statevector_gpu"`. The unitary simulator GPU method can
be accessed using `"method": "unitary_gpu"`. These backends use CUDA and require an NVidia
GPU.(\544)
- Added ``PulseSimulator`` backend (\542)
- Added ``PulseSystemModel`` and ``HamiltonianModel`` classes to represent models to be used in ``PulseSimulator`` (\496, \493)
- Added ``duffing_model_generators`` to generate ``PulseSystemModel`` objects from a list of parameters (\516)
- Migrated ODE function solver to C++ (\442, \350)
- Added high level pulse simulator tests (\379)
- CMake BLAS_LIB_PATH flag to set path to look for BLAS lib (\543)

Changed
-------
- Changed the structure of the `src` directory to organise simulator source code.
Simulator controller headers were moved to `src/controllers` and simulator method State
headers are in `src/simulators` (\544)
- 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.utils` into the `qiskit.provider.aer.utils` module.
- Enabled optimization to aggregate consecutive gates in a circuit (fusion) by default (\579).

Deprecated
----------
- Deprecated `utils.qobj_utils` functions (\568)
- Deprecated `qiskit.providers.aer.noise.device.basic_device_noise_model`. It is superseded by the
`NoiseModel.from_backend` method (\569)

Removed
-------
- Removed `NoiseModel.as_dict`, `QuantumError.as_dict`, `ReadoutError.as_dict`, and
`QuantumError.kron` methods that were deprecated in 0.3 (\568).

Changelog
========

Added
-----
- Added support for probabilities snapshot and Pauli expectation value snapshot in the stabilizer simulator (\423)

Fixed
-----
- MPS simulation method: fixed computation of snapshot_probabilities
on subsets of the qubits, in any ordering (\424)
- Fixes bug where cu3 was being applied as cu1 for unitary_simulator (\483)

Changelog

Added
-----
- Added controlled gates (``cu1``, ``cu2``, ``cu3``) to simulator basis_gates (\417)
- Added multi-controlled gates (``mcx``, ``mcy``, ``mcz``, ``mcu1``, ``mcu2``, ``mcu3``)
to simulator basis gates (\417)
- Added gate definitions to simulator backend configurations (\417)

Changed
-------
- Improved pershot snapshot data container performance (\405)
- Add basic linear algebra functions for numeric STL classes (\406)
- Improved average snapshot data container performance (\407)

CHANGELOG
==========
Fixed
-----
- Fix sdist to always attempt to build (\401)

Changelog
========

Added
-----
- Added tests for the Fredkin gate (357)
- Added tests for the cu1 gate (360)
- Added tests for statevector and stabilizer snapshots (\355)
- Added tests for density matrix snapshot (\374)
- Added tests for probabilities snapshot (\380)
- Added support for reset() in MPS simulation method (\393)
- Added tests for matrix and Pauli expectation value snapshot (\386)

Changed
-------
- Changes signature of SnapshotExpectationValue extension and the way qubit position parameters are parsed in expectation_value_matrix qobj instructions (\386)
- Change signature of SnapshotProbabilities extension (\380)
- Change signature of SnapshotDensityMatrix extension (\374)
- Stabilizer snapshot returns stabilizer instead of full Clifford table (\355)
- Signature of SnapshotStatevector and SnapshotStabilizer (\355)
- Changed all names from tensor_network_state to matrix_product_state (\356)
- Update device noise model to consume asymmetric readout errors from backends (\354)
- Update device noise model to use gate_length (\352)
- Refactoring code and introducing floating point comparison func (\338)