On Mon, Jul 12, 2010 at 1:35 PM, Zbigniew Komarnicki <cblasius at gmail.com> wrote: > When I use operator '.' I got: > e(r+1, k+1) = - C.B.K2 . e(r, k+1) - C.B.K1 . z(r+1, k) > ? ? ? ? ? ? ?- C.A . z(r+1, k) + e(r, k+1) I don't understand what is the problem here. Can you please clarify. best Robert Dodier