On Sun, 21 Feb 2010 14:33:23 -0600, Yujie <recrusader at gmail.com> wrote: > Thanks very much, Jed. > I have a vector (V) and a matrix (A), > I want to do Row_i_A.*V or Row_i_A./V (Row_i_A are the rows of A). However, > V has different format with the rows of A.
You need to do this for a small number of rows (values of i), or for many? Since vectors are dense, and since MatGetValues only provides the local part, this is not scalable. What is the problem you are trying to solve with this algebraic manipulation? There is probably a scalable way to formulate the higher-level objective to avoid these shenanigans. Jed
