Yes. I was missing the DROP argument.
But now the problem is splitting is causing some weird ordering of groups.
See below:

DF <- read.table(text="
Houseid,Personid,Tripid,taz
1,1,1,4
1,1,2,7
2,1,1,96
2,1,2,4
2,1,3,2
2,2,1,58
3,1,5,7
", header=TRUE, sep=",")
aa <- split(DF, DF[, 1:2], drop=TRUE)

Now the result is aa[3] should is (3,1) and not (2,2). Why? How can I
preserve the ascending order?

> aa[3]
$`3.1`
  Houseid Personid Tripid taz
7       3        1      5   7
> aa[4]
$`2.2`
  Houseid Personid Tripid taz
6       2        2      1  58


On Wed, Apr 4, 2012 at 6:29 AM, Rui Barradas <rui1174@sapo.pt> wrote:

> Hello,
>
>
> Ashish Agarwal wrote
>  >
> > I have a dataframe imported from csv file below:
> >
> > Houseid,Personid,Tripid,taz
> > 1,1,1,4
> > 1,1,2,7
> > 2,1,1,96
> > 2,1,2,4
> > 2,1,3,2
> > 2,2,1,58
> >
> > There are three groups identified based on the combination of first and
> > second columns. How do I split this data frame?
> >
> > I tried
> > aa <- split(inpfil, inpfil[,1:2])
> > but it has problems.
> >
> > Output desired is
> >
> > aa[1]
> >  Houseid,Personid,Tripid,taz
> > 1,1,1,4
> > 1,1,2,7
> > aa[2]
> >  Houseid,Personid,Tripid,taz
> > 2,1,1,96
> > 2,1,2,4
> > 2,1,3,2
> > aa[3]
> >  Houseid,Personid,Tripid,taz
> > 2,2,1,58
> >
> >       [[alternative HTML version deleted]]
> >
> > ______________________________________________
> > R-help@ mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide
> > http://www.R-project.org/posting-guide.html<http://www.r-project.org/posting-guide.html>
> > and provide commented, minimal, self-contained, reproducible code.
> >
>
>
> Any of the following three works with me.
>
>
> DF <- read.table(text="
> Houseid,Personid,Tripid,taz
> 1,1,1,4
> 1,1,2,7
> 2,1,1,96
> 2,1,2,4
> 2,1,3,2
> 2,2,1,58
> ", header=TRUE, sep=",")
>
> DF
>
> split(DF, DF[, 1:2], drop=TRUE)
> split(DF, list(DF$Houseid, DF$Personid), drop=TRUE)
> with(DF, split(DF, list(Houseid, Personid), drop=TRUE))
>
> The argument 'drop' defaults to FALSE. Was that the problem?
>
> Hope this helps,
>
> Rui Barrada

	[[alternative HTML version deleted]]

