[eigen] Re: Student contribution

[BRUN Gauthier <brunga@xxxxxxxxxxxxxx>]

Hi,

We have found something that could explain the bug with complexes.
When we do
MatrixType result(upperbid.householderU()* 
upperbid.bidiagonal().toDenseMatrix() * 
upperbid.householderV().adjoint());
MatrixType result2(upperbid.householderV()* 
upperbid.bidiagonal().toDenseMatrix().adjoint() * 
upperbid.householderU().adjoint())

We would expect result.adjoint() == result2 but we don't. When we print 
them we have different results. We do not know how to solve it.

We also have difficulties to affect an UpperBidiagonalization 
householder to a matrix.
The lines
std::cout << UpperBid.houseHolderU() * Identity << std::endl;
and
MatrixType U = UpperBid.houseHolderU();
std::cout << U * Identity << std::endl;
give two different results (the first one is the one we want).

Since UpperBid.houseHolderU() is an houseHolderU type and not a simple 
matrix we suppose there might be some particular way to manipulate it 
although it gives the expected result while we don't try to affect it. 
What should we do for that?

Team GL27


Jean Ceccato, Pierre Zoppitelli, Gauthier Brun, Nicolas Carre