loop problems

*To*: mathgroup at smc.vnet.net*Subject*: [mg13341] loop problems*From*: "Daniel R. Cohen" <cohend at uansv5.vanderbilt.edu>*Date*: Mon, 20 Jul 1998 02:49:58 -0400*Organization*: Vanderbilt Institute of Public Policy Studies*Sender*: owner-wri-mathgroup at wolfram.com

[Contact the author to obtain the notebook - moderator] I have two pieces of a larger problem here that are stopping the program from working, but I can't figure out what I've done wrong. I have tried to separate out what appear to be the two problems hindering evaluation of the larger expression. (In case it helps, I have again attached the entire program along with this message.) If anyone can help me with this, I could really use assistance. Perhaps it's as simple as the wrong phrasing of the indices/functions, but I'm just not sure what to do about it. 1. Even if I give Mathematica a value for each of the G[] matrices, which are all (3x3) matrices, and give it a value for t, it still is unable to do the following expression. \[Sum]\+\(i = \((t + 1)\)\)\%\(T + 1\)\(( \[Product]\+\(j = \(-i\)\)\%\(-\((t + 1)\)\)G[ Abs[j]])\)] 2. In addition, I have some nested loops within the larger problem that do not work. Following is an abbreviated version. As before, I have given the values for T, F[T+1], and G[T+1], as well as a formula related each successive G[t] to each F[t], which I've re-written just above the problematic loop. The rest should be taken care of in the iteration, as far as finding the successive values for F[t]. (A and B are given also.) MatrixForm[G[t_]=A+B.F[t]]; For[t = T, t > 0, \n\t Print[\tMatrixForm[ F[t] = \[Sum]\+\(i = \((t + 1)\)\)\%\(T + 1\)\(( F[i] . \((\[Product]\+\(j = \(-i\)\)\%\(- \((t + 1)\)\)G[Abs[j]])\) ]],t--]