CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

On 06/28/2012 03:43 PM, 

 wrote:
> Hi,
> until now I was using the CGAL 3.9 version with the TAUCS library in order
> to solve a large sparse system. As recommended in the installation manual
> I replaced TAUCS with Eigen in the 4.0 version.
> I need to write end read some auxiliary matrices in order to build the
> final large matrix which is solved with the available linear solver. With
> TAUCS I used the functions set_coef and get_coef . I don't find the
> equivalent of the get_function in the class Eigen matrix. How  can I have
> a read access to the matrix coefficient in Eigen?
Eigen_sparse_matrix and Eigen_sparse_symmetric_matrix are model of the
concep SparseLinearAlgebraTraits_d::Matrix documented in [1].

The class Eigen_matrix is not documented. Look at the end of the file
CGAL/Eigen_matrix.h for details (the documentation is roughly [2]

> Moreover, what is the
> suggested method to free memory? (I'm just using the new and delete
> operators to allocate and deallocate auxiliary matrices at main level).
In the class Eigen_sparse_matrix and Eigen_sparse_symmetric_matrix, you 
have the method eigen_object() that returns the internal matrix for 
eigen used (of type Eigen::SparseMatrix<T>). You can use Eigen methods 
to reserve memory and clear it see [3].


> Thanks in advance!


[1] 
http://www.cgal.org/Manual/latest/doc_html/cgal_manual/Surface_mesh_parameterization_ref/Concept_SparseLinearAlgebraTraits_d--Matrix.html
[2] http://eigen.tuxfamily.org/dox/classEigen_1_1Matrix.html
[3] http://eigen.tuxfamily.org/dox/classEigen_1_1SparseMatrix.html