Re: [ublas] Remove line or column from a matrix

From: Regis Behmo (regisb_at_[hidden])
Date: 2007-09-04 03:32:56

On 9/4/07, Karl Meerbergen <Karl.Meerbergen_at_[hidden]> wrote:
> Hi,
>
> I am not familiar with a mapped_matrix, but for the coordinate_matrix
> and compressed_matrix, it should be possible to implement a function to
> remove a row or a column. I think you can easily do this yourself once
> you are familiar with the format. Why do you use a mapped_matrix?
>
> Karl

Bonjour Karl,

I am not familiar with many concepts that are used in the reference
docs of ublas; therefore, the choice of the mapped_matrix structure is
probably not entirely justified. I just want to use a sparse matrix
and I don't know the difference between a mapped_matrix, a
compressed_matrix and a coordinate_matrix.

Right now, the only way I see to remove a line/column from a sparse
matrix M (M being either compressed, mapped or coordinate) would be to
make a copy of M and copy only the elements from the rows/columns
outside the removed row/column.
Do you see what I mean?
Could you give me a clue as how to do it in a more time efficient way?

Régis