[bugfix] This fixes an issue when UMFPack is found and AMG with field type float is used.

The selection of UMFPack as a direct solver does not only depend on UMFPack being found, but also whether the field type is double or complex<double>. Otherwise UMFPack cannot be used as a coarse solver in AMG. This PR fixes this issue.

@markus.blatt: Please take a look at this. 
@smuething: Please take a look at this. 

See merge request !51

Move various implementation classes into the 'Imp' namespace

There are various classes in dune-istl that are effectively implementation
classes internal to dune-istl. A few of them are base_array_unmanaged,
base_array_window, compressed_base_array_unmanaged,block_vector_unmanaged,
BlockVectorWindow, compressed_block_vector_unmanaged, CompressedBlockVectorWindow

See #22 for a brief
discussion.

This patch moves the classes into the namespace 'Imp'.  That way it is
clear that they are internal.

All code outside of dune-istl using those classes will break, but does
such code really exist?

See merge request !65

Oliver Sander authored 8 years ago and Ansgar Burchardt committed 8 years ago

There are various classes in dune-istl that are effectively implementation
classes internal to dune-istl. A few of them are base_array_unmanaged,
base_array_window, compressed_base_array_unmanaged,block_vector_unmanaged,
BlockVectorWindow, compressed_block_vector_unmanaged, CompressedBlockVectorWindow

See #22 for a brief
discussion.

This patch moves the classes into the namespace 'Imp'.  That way it is
clear that they are internal.

All code outside of dune-istl using those classes will break, but does
such code really exist?

is selected. Since UMFPack does not support this, it cannot be used in this
case.

[cleanup] fix some typos

See merge request !72

Mark various implementation classes as 'internal'

By using the doxygen \internal command.

See merge request !70

By using the doxygen \internal command.

Remove forbidden downcast

This removes several constructors and assignments from base class in the class hierarchy around `base_array`. These removed methods are all implemented using a downcast which may result in undefined behaviour.
Since they are not used anywhere in the core modules we can maybe remove them. According to @markus.blatt  these base classes are all meant to be internal.

This may cause problems if user code explicitly uses the raw base classes and these methods. However, such user code would only be valid if the passed base class reference is actually an upcasted derived class which is very unlikely.

See merge request !66

The implementation for this was hidden in the base classes
before and relied on undefined behaviour by using a downcast.
Now it is explicitly implemented for the derived classes
which also makes it more visible to users.

These constructors and assignments from base class are
all using a downcast which may result in undefined behaviour.
Since this is potentially dangerous and not used anywhere
in the core modules, this patch removes those methods.

These constructors and assignments are all implemented using
a downcast to derived class and may lead to undefined behaviour.
This commit removes the checks for these methods in preparation
for their removal.

Use `std::tuple` instead of `Dune::tuple`



See merge request !68

Fix implicit buildmode documentation and adjust test accordingly

This basically turns the issue #21 into a feature by correctly describing the constraints of the implicit build mode and the meaning of its parameters. This invalidates the test against the old interface description which is hence dropped by this MR. As a consequence the bcrsimplicitbuild-test passes again.

See merge request !63

Update test environments

- No longer test with clang 3.5.
- Add clang 3.8 from Debian 8 + backports
- Add gcc 5.4 + clang 3.8 from Ubuntu 16.04 LTS.
- Use `duneci-standard-test`

See merge request !64

- No longer test with clang 3.5.
- Add clang 3.8 from Debian 8 + backports
- Add gcc 5.4 + clang 3.8 from Ubuntu 16.04 LTS.
- Use `duneci-standard-test`

The doc now correctly describes
* that the overflow area is used during compress and not during assembly
* the meaning of avg and overflowsize
* the numbering dependence of this build mode
* the magic number 4
* the late failure during compress()

Stephan Hilb authored 8 years ago and Christoph Grüninger committed 8 years ago

This fixes the clang compiler warnings about tautological compare
when idxtype is unsigned. For clang behaviour see [1].

[1]: https://llvm.org/bugs/show_bug.cgi?id=8682

This reverts ddf49c23 and removes the check if
the average parameter behaves as expected.

[io] add vector file writer, usable for Octave and Matlab

similar to Matlab matrix writer

See merge request !61

similar to Matlab matrix writer

Fix links in INSTALL file



See merge request !59

[cleanup] Remove .gitignores and m4 folder, update README

Remove stamp-vc file.

See merge request !55

Remove stamp-vc file.

Add (static) size() method to MultiTypeBlockMatrix

Since the istl view is, that a matrix is a container of rows,
it should have a size method.

See merge request !58

Since the istl view is, that a matrix is a container of rows,
it should have a size method.

This is in fact an _unsafe_ downcast to a derived
class. Accessing members via this pointer is undefined
if it is not guaranteed that the passed pointer
points to an object of the _derived_ class - even
if the memory layout is the same. In this case
this static_cast acts like a reinterpret_cast.

If the correct average is provided, compress() may still
fail if more than the average numebr of entries are added
to an early row (e.g. the first one)

Fix broken Matrix::transpose()


Due to a confusion between the number of lines N and the number of columns M, `Matrix::transpose()` gave wrong results for matrices with N != M.

This also adds a testcase demonstrating the problem to matrixtest.cc.

See merge request !56

Due to a confusion between the number of lines N and the number of
columns M, Matrix::transpose() gave wrong results for matrices with
N != M.

Due to a bug in Matrix::transpose() it will give wrong results for
non-quadratic matrices. Thus the new test case fails for the moment.

[cleanup] Remove debug output

Remove output that printed the matrix for parallel runs for small grids n<20.

See merge request !54