[R] Processing logic for Huge Data set

[Joe Conway]

Manoj - Hachibushu Capital wrote:
>             I am new to R. I am trying to process this huge data set of
> matrix containing four columns, say x1, x2, x3, x4 and n number of rows.
> 
> I want to aggregate the matrix by x1 and perform statistic based on
> columns x2, x3, x4.

Someone will probably give you a way to do this directly in R, but if 
your data set is truly huge, at least one option is to use a PostgreSQL 
database for the data, and define a custom aggregate using PL/R. For a 
simple example, see:
   http://www.joeconway.com/plr/doc/plr-aggregate-funcs.html

HTH,

Joe