Hi,

I've seen there is an old Band Matrix implementation, and also read some threads here. It seems that only the storage scheme is supported by now, and I read that it is possible to apply Lapack functionality to the stored matrix, at least for the non-symmetric case.
Some questions:

(i) is this Band Matrix storage scheme still safely usable? Are there extensions planned?
(ii) Is there also a symmetric Band Matrix compatible with Lapack's symmetric storage scheme? Or can it be realized by SymmetricView -- or similar things -- in a way that it is also possible to use the symmetric solvers of Lapack?

Thanks in advance,
David

(I) yes, and yes.
(II) BandMatrix is naturally compatible with symmetric band storage, you simply has to set the number of super diagonals to 0 or get the address of the (0,0) element as a starting point

Thank you,
David

could you provide a short example of how to initialize the band matrix? If I include the Skyline module from the "unsupported" folder, I get a bunch full of errors ...
Thanks in advance,
David

ah, ok,

int N=1000;
Eigen::internal::BandMatrix(double,N,2,2) mat;

seems to work. I forgot the "::internal". But how do I fill it?

mat(0,0)=1.0;

doesn't work...

Best,
David

you have to fill it through its diagonals.