Message-ID: <5ea83ce3-f835-4d09-a380-a205d2db4b47@g26g2000vbi.googlegroups.com>
Date: 2011-01-11T01:23:08Z
From: analyst41 at hotmail.com
Subject: question on aggregate
an example available on the net goes like
> df
identifier quantity
1 1 10
2 1 20
3 2 30
4 1 15
5 2 10
6 3 20
> aggregate(df$quantity, by=list(df$identifier), sum)
Group.1 x
1 1 45
2 2 40
3 3 20
I'd like Group.1 to retain the name "identifier" and would like to
control what "x" get called in the output. Thanks.