Dear petsc users, I need to compute the difference of two matrices M(nu) and M(nu+epsilon) to estimate the derivative of the matrix with respect to the parameter nu. Since only very few entries are modified by epsilon, D = M(nu+epsilon) - M(nu) contains many new zeros and I would like to remove them.
I am using PETSc from petsc4py. I have seen the method `chop` which call `Filter` but without the `compress` argument. At the end I need to store this matrix into a file. So my questions are: - Is is possible to remove the zeros entries with petsc4py with Mat methods? - Is is possible to do it when I save the file, ie with Viewer methods ? Thanks a lot, Benoit
