Matrix Expansion question to Mathgroup

*To*: mathgroup at smc.vnet.net*Subject*: [mg47738] Matrix Expansion question to Mathgroup*From*: "Larry Caruso" <lcaruso at tds.net>*Date*: Sat, 24 Apr 2004 04:15:36 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

I emailed the Mathgroup submission request (below) yesterday, 4/22, but since it did not appear in today's listing, I assume it was somehow trivial. However, I've been unable to locate a similar question elsewhere. Can you provide further guidance? I have a large, square matrix where each m[[ i, j ]] is populated with f[ i, j ], which happens to be a list {dx, dy}. At some later date, having collected more data, I want to expand matrix this to a larger square matrix using the same f [ i, j ] without losing any previously stored information. Since the matrix is huge, regenerating it takes far too long, so I want to simply add on the new data. I've tried experimenting with AppendRows[] and other routines, but they only operate on non-lists. As far as I can determine, using a C compiler with Mathlink may be my only option where I'm regenerating the matrix from scratch as quickly as possible instead of adding only new data. Are there any other reasonable possibilities? Thanks.