CHANGELOG.rst

Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog.

Types of changes:

• Added: for new features.
• Changed: for changes in existing functionality.
• Deprecated: for soon-to-be removed features.
• Removed: for now removed features.
• Fixed: for any bug fixes.
• Security: in case of vulnerabilities.

UNRELEASED

Added

• Added DAG visualizer (#1059)

Changed

• Evolved pass-based transpiler to support advanced functionality (#1060)

Deprecated

• plot_circuit(), latex_circuit_drawer(), generate_latex_source(),

  and matplotlib_circuit_drawer() from qiskit.tools.visualization are deprecated. Instead the circuit_drawer() function from the same module should be used. (#1055)

• The current default output of circuit_drawer() (using latex and falling

  back on python) is deprecated and will be changed in the future. (#1055)

Fixed

• Fixed horizontal spacing when drawing barriers before CCNOT gates in latex circuit plots (#1051)

0.6.0 - 2018-10-04

Added

• Added SchemaValidationError to be thrown when schema validation fails (#881)
• Generalized Qobj schema validation functions for all qiskit schemas (#882).
• Added decorator to check for C++ simulator availability (#662)
• It is possible to cancel jobs in non comercial backends (#687)
• Introduced new qiskit.IBMQ provider, with centralized handling of IBMQ credentials (qiskitrc file, environment variables). (#547, #948, #1000)
• Add OpenMP parallelization for Apple builds of the cpp simulator (#698).
• Add parallelization utilities (#701)
• Parallelize transpilation (#701)
• New interactive visualizations (#765).
• Added option to reverse the qubit order when plotting a circuit. (#762, #786)
• Jupyter notebook magic function qiskit_job_status, qiskit_progress_bar (#701, #734)
• Add a new function qobj_to_circuits to convert a Qobj object to a list of QuantumCircuit objects (#877)
• Allow selective loading of accounts from disk via hub/group/project filters to IBMQ.load_accounts().

Changed

• Schema tests in tests/schemas/test_schemas.py replaced with proper unit test (#834).
• Renamed QISKit to Qiskit in the documentation. (#634)
• Use Qobj as the formally defined schema for sending information to the devices: - introduce the qiskit.qobj module. (#589, #655) - update the Qobj JSON schema. (#668, #677, #703, #709) - update the local simulators for accepting Qobj as input. (#667) - update the Result class. (#773)
• Use get_status_job() for checking IBMQJob status. (#641)
• Q network hub/group/project credentials replaced by new url format. (#740)
• Breaking change: Jobs API simplification. (#686)
• Breaking change: altered tomography APIs to not use QuantumProgram. (#818)
• Breaking change: BaseBackend API changed, properties are now methods (#858)
• When plot_histogram() or plot_state() are called from a jupyter notebook if there is network connectivity the interactive plots will be used by default (#862, #866)
• Breaking change: BaseJob API changed, any job constructor must be passed the backend used to run them and a unique job id (#936).
• Add support for drawing circuit barriers to the latex circuit drawer. This requires having the LaTeX qcircuit package version >=2.6.0 installed (#764)

Deprecated

• The number_to_keep kwarg on the plot_histogram() function is now deprecated. A field of the same name should be used in the option dictionary kwarg instead. (#866)
• Breaking change: backend.properties() instead of backend.calibration() and backend.parameters() (#870)

Removed

• Removed the QuantumProgram class. (#724)

Fixed

• Fixed get_ran_qasm methods on Result instances (#688).
• Fixed probabilities_ket computation in C++ simulator (#580).
• Fixed bug in the definition of cswap gate and its test (#685).
• Fixed the examples to be compatible with version 0.5+ (#672).
• Fixed swap mapper using qubits after measurement (#691).
• Fixed error in cpp simulator for 3+ qubit operations (#698).
• Fixed issue with combining or extending circuits that contain CompositeGate (#710).
• Fixed the random unitary generation from the Haar measure (#760).
• Fixed the issue with control lines spanning through several classical registers (#762).
• Fixed visualizations crashing when using simulator extensions (#885).
• Fixed check for network connection when loading interactive visualizations (#892).
• Fixed bug in checking that a circuit already matches a coupling map (#1024).

0.5.7 - 2018-07-19

Changed

• Add new backend names support, with aliasing for the old ones.

0.5.6 - 2018-07-06

Changed

• Rename repository to qiskit-terra (#606).
• Update Bloch sphere to QuTiP version (#618).
• Adjust margin of matplotlib_circuit_drawer (#632)

Removed

• Remove OpenQuantumCompiler (#610).

Fixed

• Fixed broken process error and simulator slowdown on Windows (#613).
• Fixed yzy_to_zyz bugs (#520, #607) by moving to quaternions (#626).

0.5.5 - 2018-07-02

Added

• Retrieve IBM Q jobs from server (#563, #585).
• Add German introductory documentation (doc/de) (#592).
• Add unregister() for removing previously registered providers (#584).
• Add matplotlib-based circuit drawer (#579).
• Adding backend filtering by least busy (#575).
• Allow running with new display names for IBMQ devices, and return those from available_backends() (#566)
• Introduce Qiskit Transpiler and refactor compilation flow (#578)
• Add CXCancellation pass (#578)

Changed

• Remove backend filtering in individual providers, keep only in wrapper (#575).
• Single source of version information (#581)
• Bumped IBMQuantumExperience dependency to 1.9.6 (#600).
• For backend status, status['available'] is now status['operational'] (#609).
• Added support for registering third-party providers in register() (#602).
• Order strings in the output of available_backends() (#566)

Removed

• Remove Clifford simulator from default available_backends, until its stable release (#555).
• Remove ProjectQ simulators for moving to new repository (#553).
• Remove QuantumJob class (#616)

Fixed

• Fix issue with unintended inversion of initializer gates (#573).
• Fix issue with skip_transpiler causing some gates to be ignored silently (#562).

0.5.4 - 2018-06-11

Added

• Performance improvements:

  • remove deepcopies from dagcircuit, and extra check on qasm() (#523).

Changed

• Rename repository to qiskit-core (#530).
• Repository improvements: new changelog format (#535), updated issue templates (#531).
• Renamed the specification schemas (#464).
• Convert LocalJob tests into unit-tests. (#526)
• Move wrapper load_qasm_* methods to a submodule (#533).

Removed

• Remove Sympy simulators for moving to new repository (#514)

Fixed

• Fix erroneous density matrix and probabilities in C++ simulator (#518)
• Fix hardcoded backend mapping tests (#521)
• Removed _modifiers call from reapply (#534)
• Fix circuit drawer issue with filename location on windows (#543)
• Change initial qubit layout only if the backend coupling map is not satisfied (#527)
• Fix incorrect unrolling of t to tdg in CircuitBackend (#557)
• Fix issue with simulator extension commands not reapplying correctly (#556)

0.5.3 - 2018-05-29

Added

• load_qasm_file / load_qasm_string methods

Changed

• Dependencies version bumped

Fixed

• Crash in the cpp simulator for some linux platforms
• Fixed some minor bugs

0.5.2 - 2018-05-21

Changed

• Adding Result.get_unitary()

Deprecated

• Deprecating ibmqx_hpc_qasm_simulator and ibmqx_qasm_simulator in favor of ibmq_qasm_simulator.

Fixed

• Fixing a Mapper issue.
• Fixing Windows 7 builds.

0.5.1 - 2018-05-15

• There are no code changes.

  MacOS simulator has been rebuilt with external user libraries compiled statically, so there’s no need for users to have a preinstalled gcc environment.

  Pypi forces us to bump up the version number if we want to upload a new package, so this is basically what have changed.

0.5.0 - 2018-05-11

Improvements

• Introduce providers and rework backends (#376).

  • Split backends into local and ibmq.
  • Each provider derives from the following classes for its specific requirements (BaseProvider, BaseBackend, BaseJob).
  • Allow querying result by both circuit name and QuantumCircuit instance.

• Introduce the Qiskit wrapper (#376).

  • Introduce convenience wrapper functions around commonly used Qiskit components (e.g. compile and execute functions).
  • Introduce the DefaultQISKitProvider, which acts as a context manager for the current session (e.g. providing easy access to all available_backends).
  • Avoid relying on QuantumProgram (eventual deprecation).
  • The functions are also available as top-level functions (for example, qiskit.get_backend()).

• Introduce BaseJob class and asynchronous jobs (#403).

  • Return BaseJob after run().
  • Mechanisms for querying status and results, or to cancel a job.

• Introduce a skip_transpiler flag for compile() (#411).

• Introduce schemas for validating interfaces between qiskit and backends (#434)

  • qobj_schema
  • result_schema
  • job_status_schema
  • default_pulse_config_schema
  • backend_config_schema
  • backend_props_schema
  • backend_status_schema

• Improve C++ simulator (#386)

  • Add tensor_index.hpp for multi-partite qubit vector indexing.
  • Add qubit_vector.hpp for multi-partite qubit vector algebra.
  • Rework C++ simulator backends to use QubitVector class instead of std::vector.

• Improve interface to simulator backends (#435)

  • Introduce local_statevector_simulator_py and local_statevector_simulator_cpp.
  • Introduce aliased and deprecated backend names and mechanisms for resolving them.
  • Introduce optional compact flag to query backend names only by unique function.
  • Introduce result convenience functions get_statevector, get_unitary
  • Add snapshot command for caching a copy of the current simulator state.

• Introduce circuit drawing via circuit_drawer() and plot_circuit() (#295, #414)
• Introduce benchmark suite for performance testing (test/performance) (#277)
• Introduce more robust probability testing via assertDictAlmostEqual (#390)
• Allow combining circuits across both depth and width (#389)
• Enforce string token names (#395)

Fixed

• Fix coherent error bug in local_qasm_simulator_cpp (#318)
• Fix the order and format of result bits obtained from device backends (#430)
• Fix support for noises in the idle gate of local_clifford_simulator_cpp (#440)
• Fix JobProcessor modifying input qobj (#392) (and removed JobProcessor during #403)
• Fix ability to apply all gates on register (#369)

Deprecated

• Some methods of QuantumProgram are soon to be deprecated. Please use the top-level functions instead.
• The Register instantiation now expects size, name. Using name, size is still supported but will be deprecated in the future.
• Simulators no longer return wavefunction by setting shots=1. Instead, use the local_statevector_simulator, or explicitly ask for snapshot.
• Return job instance after run(), rather than result.
• Rename simulators according to PROVIDERNAME_SIMPLEALIAS_simulator_LANGUAGEORPROJECT
• Move simulator extensions to qiskit/extensions/simulator
• Move Rzz and CSwap to standard extension library

0.4.15 - 2018-05-07

Fixed

• Fixed an issue with legacy code that was affecting Developers Challenge.

0.4.14 - 2018-04-18

Fixed

• Fixed an issue about handling Basis Gates parameters on backend configurations.

0.4.13 - 2018-04-16

Changed

• OpenQuantumCompiler.dag2json() restored for backward compatibility.

Fixed

• Fixes an issue regarding barrier gate misuse in some circumstances.

0.4.12 - 2018-03-11

Changed

• Improved circuit visualization.
• Improvements in infrastructure code, mostly tests and build system.
• Better documentation regarding contributors.

Fixed

• A bunch of minor bugs have been fixed.

0.4.11 - 2018-03-13

Added

• More testing :)

Changed

• Stabilizing code related to external dependencies.

Fixed

• Fixed bug in circuit drawing where some gates in the standard library were not plotting correctly.

0.4.10 - 2018-03-06

Added

• Chinese translation of README.

Changed

• Changes related with infrastructure (linter, tests, automation) enhancement.

Fixed

• Fix installation issue when simulator cannot be built.
• Fix bug with auto-generated CNOT coherent error matrix in C++ simulator.
• Fix a bug in the async code.

0.4.9 - 2018-02-12

Changed

• CMake integration.
• QASM improvements.
• Mapper optimizer improvements.

Fixed

• Some minor C++ Simulator bug-fixes.

0.4.8 - 2018-01-29

Fixed

• Fix parsing U_error matrix in C++ Simulator python helper class.
• Fix display of code-blocks on .rst pages.

0.4.7 - 2018-01-26

Changed

• Changes some naming conventions for amp_error noise parameters to calibration_error.

Fixed

• Fixes several bugs with noise implementations in the simulator.
• Fixes many spelling mistakes in simulator README.

0.4.6 - 2018-01-22

Changed

• We have upgraded some of out external dependencies to:

  • matplotlib >=2.1,<2.2
  • networkx>=1.11,<2.1
  • numpy>=1.13,<1.15
  • ply==3.10
  • scipy>=0.19,<1.1
  • Sphinx>=1.6,<1.7
  • sympy>=1.0

0.4.4 - 2018-01-09

Changed

• Update dependencies to more recent versions.

Fixed

• Fix bug with process tomography reversing qubit preparation order.

0.4.3 - 2018-01-08

Removed

• Static compilation has been removed because it seems to be failing while installing Qiskit via pip on Mac.

0.4.2 - 2018-01-08

Fixed

• Minor bug fixing related to pip installation process.

0.4.0 - 2018-01-08

Added

• Job handling improvements.

  • Allow asynchronous job submission.
  • New JobProcessor class: utilizes concurrent.futures.
  • New QuantumJob class: job description.

• Modularize circuit "compilation".

  Takes quantum circuit and information about backend to transform circuit into one which can run on the backend.

• Standardize job description.

  All backends take QuantumJob objects which wraps qobj program description.

• Simplify addition of backends, where circuits are run/simulated.

  • qiskit.backends package added.
  • Real devices and simulators are considered "backends" which inherent from BaseBackend.

• Reorganize and improve Sphinx documentation.
• Improve unittest framework.
• Add tools for generating random circuits.
• New utilities for fermionic Hamiltonians (qiskit/tools/apps/fermion).
• New utilities for classical optimization and chemistry (qiskit/tools/apps/optimization).
• Randomized benchmarking data handling.

• Quantum tomography (qiskit/tools/qcvv).

  Added functions for generating, running and fitting process tomography experiments.

• Quantum information functions (qiskit/tools/qi).

  • Partial trace over subsystems of multi-partite vector.
  • Partial trace over subsystems of multi-partite matrix.
  • Flatten an operator to a vector in a specified basis.
  • Generate random unitary matrix.
  • Generate random density matrix.
  • Generate normally distributed complex matrix.
  • Generate random density matrix from Hilbert-Schmidt metric.
  • Generate random density matrix from the Bures metric.
  • Compute Shannon entropy of probability vector.
  • Compute von Neumann entropy of quantum state.
  • Compute mutual information of a bipartite state.
  • Compute the entanglement of formation of quantum state.

• Visualization improvements (qiskit/tools).

  • Wigner function representation.
  • Latex figure of circuit.

• Use python logging facility for info, warnings, etc.
• Auto-deployment of sphinx docs to github pages.
• Check IBMQuantumExperience version at runtime.
• Add QuantumProgram method to reconfigure already generated qobj.
• Add Japanese introductory documentation (doc/ja).
• Add Korean translation of readme (doc/ko).
• Add appveyor for continuous integration on Windows.
• Enable new IBM Q parameters for hub/group/project.
• Add QuantumProgram methods for destroying registers and circuits.
• Use Sympy for evaluating expressions.
• Add support for ibmqx_hpc_qasm_simulator backend.

• Add backend interface to Project Q C++ simulator.

  Requires installation of Project Q.

• Introduce InitializeGate class.

  Generates circuit which initializes qubits in arbitrary state.

• Introduce local_qiskit_simulator a C++ simulator with realistic noise.

  Requires C++ build environment for make-based build.

• Introduce local_clifford_simulator a C++ Clifford simulator.

  Requires C++ build environment for make-based build.

Changed

• The standard extension for creating U base gates has been modified to be consistent with the rest of the gate APIs (see #203).

Removed

• The silent parameter has been removed from a number of QuantumProgram methods. The same behaviour can be achieved now by using the enable_logs() and disable_logs() methods, which use the standard Python logging.

Fixed

• Fix basis gates (#76).
• Enable QASM parser to work in multiuser environments.
• Correct operator precedence when parsing expressions (#190).
• Fix "math domain error" in mapping (#111, #151).