[Boost-users] [boost::ublas] Question on compressed_matrix

Subject: [Boost-users] [boost::ublas] Question on compressed_matrix
From: Bastian Sdorra (bsdorra_at_[hidden])
Date: 2008-12-02 13:53:53

Hello everybody,

I have a question on ublas::compressed_matrix.
I need to build a submatrix of a compressed_matrix. This should also be a
compressed_matrix composed out of different rows of the original matrix. I have
a std::set containing all row-indicis of the original matrix rows the submatrix
should contain. Here is my problem, I can't find a way to do this.
I know that there is a way to get rows out of a matrix. But these are dense rows
-> too much unneeded data (Is there a way to insert complete rows at all?).
Is there a way to copy a row of a compressed_matrix as compressed_vector and
insert the vector in another compressed_matrix?
I also thought about extracting only the values!=0 of the individual rows like
  here:

http://guwi17.de/ublas/matrix_sparse_usage.html

but I don't want to iterate over all rows and test if the set contains the
rowindex.
It would be very nice, if someone could give me a hint how to solve this problem.

Thanks and regards

Bastian