0.6.1

New Features

• Speed up PresolverImpl::normalization_remove_invalid_markers() C++ method. This gives faster presolve normalization times for models with many discrete constraints.
• Speed up PresolverImpl::technique_remove_small_biases() C++ method. This gives faster presolve times for models with many small biases.

0.6.0

New Features

• Make SpinReversalTransformComposite nonblocking.

• Add a seed parameter to the constructor of SpinReversalTransformComposite.

• Improve the performance of the Presolver constructor by avoiding an unnecessary copy.

• Raise an InvalidModelError from Presolver when given a model with float("nan") bounds.

• Raise an InvalidModelError from Presolver when given a model that has a constraint with float("nan") weight or rhs.

• Add C++ Presolver::restore() method for restoring samples.

• Add domain propagation to dwave::presolve::Presolver.

• Add removing small biases to dwave::presolve::Presolver.

• Support Numpy>=1.17.3, previously required NumPy>=1.20.0.

• Add a presolve normalization step to replace inf biases, bounds, offsets, right-hand-sides, etc with a large finite number.

• A newly instantiated Presolver will now have presolve techniques loaded by default.

• Add TechniqueFlags enum to represent different presolve techniques.

• Add C++ dwave::presolve::Presolver::add_techniques(), dwave::presolve::Presolver::set_techniques(), and dwave::presolve::Presolver::techniques() methods for manipulating the presolve techniques that will be used by the presolver.

• Update Presolver.apply(), Presolver.normalize(), and Presolver.presolve() to release Python's global interpreter lock (GIL).

• Reimplement the C++ Presolver using the PImpl pattern. This will make it easier to maintain binary compatibility going forward. See #89.

• Add dwave::presolve::Presolve::normalize() C++ method.

• Add dwave::presolve::Presolve::presolve() C++ method.

• Raise an InvalidModelError from Presolver when given a model with float("nan") biases.

• Add Presolver.feasibility() method to return a Feasibility enum. This can be used to test the feasibility of presolved models.

• Add time_limit_s keyword argument to Presolver.presolve().

• Add time_limit argument to C++ method dwave::presolve::Presolver::presolve().

• Add Presolver.normalize() method. See #78.

• Add Presolver.presolve() method. See #78.

Upgrade Notes

• The wrapped C++ dwave::presolve::Presolver held by cyPresolver.cpppresolver is now stored as a pointer.

• Remove C++ PostSolver class. See #90.

• A newly instantiated Presolver will now have presolve techniques loaded by default. Previously it would have no techniques loaded and the user would need to also call Presolver.load_default_presolvers().

• Remove the C++ dwave::presolve::Presolver::load_default_presolvers() method.

• The C++ Presolver no longer has a header-only implementation.

• Raise an InvalidModelError rather than a RuntimeError when presolving a detached model.

• Change Presolver to no longer raise an InfeasibleModelError error for infeasible models.

• Remove the InfeasibleModelError.

Deprecation Notes

• Drop support for Python 3.7.

• Deprecate Presolver.load_default_techniques(). Use Presolver.set_techniques(TechniqueFlags.Default) instead.

0.5.4

Prelude

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New Features

• Release wheels for Python 3.11

0.5.3

Features

• Remove interactions and variables with 0 bias in Presolver

Fixes

• Fix handling of empty soft constraint in Presolver.

0.5.2

Fixes

• Fix case where Presolver was incorrectly leaving variables fixed by bounds in the model

0.5.1

Fixes

• Fix case where Presolver was incorrectly marking constraints with no variables as infeasible.

0.5.0.dev4

Fixes

• Fix case where Presolver was incorrectly marking constraints with no variables as infeasible.

0.5.0

New Features

• Add CQM presolving.

0.5.0.dev3

Fixes

• Use dimod 0.12.0.dev3 which contains bug fixes

0.5.0.dev2

Fixes

• Fix Presolver.restore_samples() throwing segmentation faults in some cases