[ublas] subrange and project

Subject: [ublas] subrange and project
From: Umut Tabak (u.tabak_at_[hidden])
Date: 2010-01-25 16:21:24

Dear all,

I was trying to interface some sparse system matrices to Petsc by using 
Boost libraries. I have some block
matrices that I would like to set, say

M1 M2 0
0     M3 0
0    M4 0

 I checked that there are subrange and project functions for these tasks 
but I tried on a matrix to set a block of size 7845X7845, it went pretty 
slow, should I know sth about these methods to make this block 
assignment operations faster.

Any pointers are appreciated.

Best regards,
Umut