Detailed Description

template<class Base>
class Dune::Assembler::SingleRowMatrix< Base >

Tag matrix as single row matrix.

Template Parameters

Base	The base matrix type that should be tagged.

This class helps to solve the problem, that the distribution of digits from non-uniform row- and column-multi-indices to the different levels of a nested matrix cannot be done generically.

The reason for this problem is, that all matrices in Dune need a row and a column index to access their entries. Hence, for a nested matrix the row and column multi-index always need to have the same length. However, there are natural applications of multi-indices with non-uniform length (e.g. for the Stokes problem). In this case it is implicitly assumed that for certain matrices in the nested matrix hierarchy only a column or row index is provided. In practice this means, you need to insert a zero-digit at the correct position in the complementary multi-index. Unfortunately, this cannot be done automatically, because there are many candidates for this position and it's in fact a user choice, which one is correct.

To solve this, one can tag a matrix type Base as single-row by using SingleRowMatrix<Base> instead. Then the algorithm for dispatching multi-indices knows, that it has to insert a zero digit into the row multi-index here.

The class derives from Base and inherits all its members without overwriting any and can thus be used as a replacement for Base.

The documentation for this class was generated from the following file:

singlerowcolmatrix.hh