[R] kunamorph@web.de

[Christfried Kunath]

Hello,

how can I use the function "cor()" with x and y in function 
"aggregate()" or "by()"?

The data are like this:
x   y   group
1   4   B
2   4   B
3   5   C

I would like obtain the correlation between x and y for each subset. I 
don't want to use the workaround with the function subset(), because I 
have many groups.

Thanks in advance.
Christfried Kunath KC