CholmodSolver: Allow to reuse a factorization

See merge request !67

oliver.sander_at_tu-dresden.de authored Oct 15, 2021 and Patrick Jaap committed Jun 23, 2022

Computing Cholesky factorizations is expensive, and they absolutely
have to be reused if the same linear system is solved with several
different right hand sides.  The previous implementation of
CholmodSolver wouldn't allow this: The 'solve' method factorized
and solved together.

This patch makes the interface of the CholmodSolver class richer
to allow for factorization reuse.  It is now possible to set the
matrix, rhs and solution storage separately.  The matrix can be
factorized by calling a new 'factorize' method, and if 'solve'
is called afterwards, the matrix won't be factorized again.

On the other hand, when calling 'solve' by itself the 'solve'
method will do the factorization.  In other words, the patch
is fully backward-compatible.

Replace DUNE_DEPRECATED by [[deprecated]]

See merge request !66

TupleVector: inherit all constructors from std::tuple

See merge request !65

The previous implementation caused unwanted passes of std::is_assignable with bool.
Furthermore, the previous implementation provided a variadic constructor without any restrictions causing hard to track compiler errors in the std::forward part.

Replace HAVE_UG by HAVE_DUNE_UGGRID

See merge request !64

Because HAVE_UG has been removed.

EnergyNorm: add getMatrix() method

See merge request !62

cmake: use keyword signature of target_link_libraries

See merge request !61

Fix: LoopSolver has to execute the criteria regardless of the verbosity mode

See merge request !59

Fix return type in IterativeSolver

See merge request !60

In the current implementation this caused different solution behavior depending
on the chosen verbosity mode. Plain stop critera
were ignored in the SOLVER::QUIET case.

This patch fixed the problem.

LoopSolver: Add getter for the current convergence rate

See merge request !56

Make TwoNorm more generic

See merge request !55

Adapt CholmodSolver to (almost) arbitrary matrix types

See merge request !53

This is a follow-up change from the dune-istl Cholmod changes in
https://gitlab.dune-project.org/core/dune-istl/-/merge_requests/424

Now it also works for multi type vectors

Replace DUNE_UNUSED by [[maybe_unused]]

See merge request !54

Add missing namespace fixes for addToDiagonal

See merge request !52

Apparently the calls are not used anywhere in dune-solvers
itself, that's why the CI system didn't catch the problem.

UMFPackSolver with scalar matrix entries

See merge request !51

Previously, the class SymmetricSampleProblem would always produce
matrices and vectors with FieldMatrix/FieldVector entries of a given
user-controllable blocksize.  With this patch, the blocksize can
also be set to 0.  In that case, the resulting matrices and vectors
have 'double' entries.

In that case the BitVector will be the input vector type, but with
entry type 'char'.

Interval: handle negative multiplication

See merge request !50

Interval: scalar multiplication

See merge request !49

Fix bug in MultigridStep constructor

See merge request !45

Remove deprecated stuff from tests

See merge request !46