MathGroup Archive 2004

[Date Index] [Thread Index] [Author Index]

Search the Archive

Matrix Expansion question to Mathgroup

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

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.

  • Prev by Date: Re: Superscripts and subscripts in a text cell?
  • Next by Date: RE: Superscripts and subscripts in a text cell?
  • Previous by thread: Re: Problem With "Copy Input from Above"
  • Next by thread: RE: Matrix Expansion question to Mathgroup