CHANGELOG.md

Master (will become release 2.8)

• Added public access of the cholmod_common object in class Cholmod.

• Python bindings have been moved from the dune-python module which is now obsolete. Note that for dune-istl bindings are still very much work in progress. To activate Python bindings the CMake flag DUNE_ENABLE_PYTHONBINDINGS needs to be turned on (default is off). Furthermore, flags for either shared library or position independent code needs to be used.

• Added new utility functions templates maxBlockLevel, minBlockLevel, blockLevel in dnue/istl/blocklevel.hh to automatically determine the block level of possibly nested ISTL vectors & matrices at compile time. The block level cannot be always uniquely determined for MultiTypeBlockMatrix/MultiTypeBlockVector since the nesting level of different block types might differ. Hence, maxBlockLevel, minBlockLevel always works but if they yield different results blockLevel will not compile. This condition can be checked with the function template hasUniqueBlockLevel.

• The internal setup code of the various SuiteSparse solvers (like UMFPack) has been cleaned up. The effects should be invisible to all regular users. However, if you have happened to use the ColCompMatrix and ColCompMatrixInitializer classes in the past you need to port your code to use Impl::BCCSMatrix and Impl::BCCSMatrixInitializer instead. Their interfaces have changed a little bit; please look at the class documentation for details. The old header colcompmatrix.hh is still there, but backward compatibility is only partial.

Deprecations and removals

• Drop deprecated bindings of direct solver Pardiso.

• Remove deprecated preconditioner implementations SeqILU0 and SeqILUn. Use SeqILU instead, which implements incomplete LU decomposition of any order.

• Remove deprecated methods 'BlockVector::resize' and 'BlockVector::reserve' with two arguments.

• Drop support SuperLU 4.

• Rename the exception ImplicitModeOverflowExhausted to ImplicitModeCompressionBufferExhausted, to better reflect its meaning. The old exception is still there, but it triggers a deprecation warning.

Release 2.7

• New SolverFactory for generating sequential direct or iterative solvers and preconditioners from a ParameterTree configuration.

• BDMatrix objects now have the method solve, which implements that canonical way to solve block-diagonal linear systems.

• The class VariableBlockVector::CreateIterator is a true STL output iterator now. This means that you can use STL algorithms like std::fill or std::copy to set the block sizes.

• MultiTypeBlockVector<Args...> now inherits the constructors from its parent type (std::tuple<Args...>). This means you can now also construct MultiTypeBlockVectors from values or references of BlockVectors.

• All matrix and vector classes can now be instantiated with number types directly (A number type is any type for which Dune::IsNumber<T>::value is true). For example, you can now use BlockVector<double> instead of the more cumbersome BlockVector<FieldVector<double,1> >. Similarly, you can use BCRSMatrix<double> instead of BCRSMatrix<FieldMatrix<double,1,1>>. The old forms still work, and FieldVector and FieldMatrix types with a single entry can still be cast to their field_type. Therefore, the change is completely backward-compatible.

• Added a right-preconditioned flexible restarted GMRes solver

• The UMFPack binding use the long int functions to compute larger systems. With the *dl* versions instead of the *di* versions UMFPACK will not have a memory limit of just 2 GiB.

• Support for SuiteSparse's CHOLMOD providing a sparse Cholesky factorization.

• The interface methods dot() and norm() of ScalarProduct are now const. You will have to adjust the method signatures in your own scalar product implementations.

• MultiTypeBlockVector now implements the interface method N(), which returns the number of vector entries.

• MultiTypeBlockVector now implements the interface method dim(), which returns the number of scalar vector entries.

• MultiTypeBlockVector::count() is now const

• SeqILU can now be used with SIMD data types.

Deprecations and removals

• Deprecated support for SuperLU 4.x. It will be removed after Dune 2.7.

• Deprecated the preconditioner implementations SeqILU0 and SeqILUn. Use SeqILU instead, which implements incomplete LU decomposition of any order.

• The method setSolverCategory of OwnerOverlapCopyCommunication is deprecated and will be removed after Dune 2.7. The solver category can only be set in the constructor.

• The method getSolverCategory of OwnerOverlapCopyCommunication is deprecated and will be removed after Dune 2.7. Use category() instead.

• The method MultiTypeBlockVector::count() has been deprecated, because its name is inconsistent with the name mandated by the dune-istl vector interface.

• The method MultiTypeBlockMatrix::size() has been deprecated, because its name is inconsistent with the name mandated by the dune-istl vector interface.

Release 2.6

• BDMatrix objects can now be constructed and assigned from std::initializer_list.

• BDMatrix and BTDMatrix now implement the setSize method, which allows to resize existing matrix objects.

• The solver infrastructure was updated to support SIMD data types (see current changes in dune-common). This allows to solve multiple systems simultaniously using vectorization.