On Mon, Aug 4, 2008 at 3:14 AM, Ahmed El Zein <ahmed at azein.com> wrote: > I am working on a project where I would like to copy a sparse matrix in > CSR format. > > I have tried MatGetRow() which works OK but I would really like to get > pointers to the 3 arrays directly. > > I also tried MatGetRowIJ() which allows me to get the i and j arrays but > I can't see how to access the nonzero elements.
You can use MatGetArray(). Matt > and finally I attempted to access the arrays directly like this: > Mat_SeqAIJ *a = (Mat_SeqAIJ*)A->data; > MatScalar *val = a->a; > PetscInt *ptr = a->i; > PetscInt *ind = a->j; > > However when accessing directly I get different values for ptr and > SIGSEGV when accessing val or ind. > > also I get a bogus number for a->nz (134630032 instead of 21) > > Can someone please explain when I am doing wrong? > > Ahmed > > -- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener