> < ^ Date: Tue, 15 Aug 2000 18:22:15 +0900 (JST)
^ From: Sou Okada <sou@twics.com >
> ^ Subject: New functions for Association Scheme and one question

Dear gap-forum,

My name is OKADA, Sou studying Association Scheme.
An association scheme is, roughly speaking,
the set of 0-1 matrices R such that
Dimension(Algebra(R,field))=Size(R) where the field
usually refers to the complex field. GAP is
quite useful for our research area.

I have made new functions for association schemes at

http://science.icu.ac.jp/~so/index-e.html

You can study well Association Scheme by the functions.
I designed them to be capable to handle them not only
on the usual rational or complex field but also on an
any finite field. Especially, my first motivation
was to make a program to see the association scheme
from a TypeII matrice on a finite field.
I hope some of you may be interested in my functions

```-------------

I encountered one strange behavior of GAP4 4r2 fix4.
That is
gap>W:=[[1,1,1],[1, E(3), E(3)^2],[1,E(3)^2,E(3)]];;
gap>Sum([[1,2]],i-> W{[i]});
[[1,1,1],[1,E(3),E(3)^2]]

I think this is strange. Since IsDenseList(W{[1,2]})
returns true, so it could be better that
Sum([[1,2]],i-> W{[i]}) returns [2,-E(3)^2, -E(3)] .
```