On 03/30/2011 03:50 AM, Oscar Vargas wrote:
Thank you very much for your fine answer. As a matter of fact, I had studied the reference you gave me, and that was pretty clear for me. Maybe my question wasn't formulated correctly. Maybe, the question was

"Is there a more practical way to ..."

reply to ublas list as well, not to individuals, so that your chances of getting a better answer increases :)
 
Questions to start with,

are matrices dense, sparse, banded or ? Depending on this selection, there are ways to insert elements. There are even a lot previous discussions on how to insert elements into sparse matrices in a fast way for instance.

The below code just does some convenient initialization tricks he devised I guess, I did not look into the detail though.
For example, I found this code (at  http://www.guwi17.de/ublas/examples/ex_ro_adapt.cpp)

#include <iostream>
Still not clear to me what you are asking, but more knowledgeable posters will show up I suppose.
-- 
If I have a thousand ideas and only one turns out to be good, 
I am satisfied.
Alfred Nobel