[R] Creating dataframe names on the fly?

[Stavros Macrakis]

On Fri, Mar 20, 2009 at 8:18 PM, science! <karthik.ram at gmail.com> wrote:
> I am aware that it is easily possible to create var names on the fly. e.g.
> assign(paste("m",i,sep=""),j)
> but is it possible to assign dataframes to variables created on the fly?
>
> e.g.
> If I have a dataframe called master and I wanted to subset parts of those
> data into separate dataframes, I could do:
>
> m1=subset(master,master$SAMPLE=='1')
> m2=subset(master,master$SAMPLE=='2')
> .....
>
> but I would like to do this in a loop. Can someone give me suggestions on
> how to accomplish this?

Assuming this is a good idea (a priori I am sceptical), the following
works just fine.  What problems did you run into?

> master <- data.frame(a=sample(3,8,replace=TRUE),b=rnorm(8))
> for (i in 1:3) assign(paste("m",i,sep=""),subset(master,a==i))
> m1
  a          b
1 1 0.01395752
3 1 0.58781916
4 1 2.30619952
> m2
  a           b
5 2 -0.21210500
7 2 -1.12641675
8 2  0.01753290
> m3
  a         b
2 3 -0.957271
6 3  2.035773