Re: [R] data manipulation

From: Sebastian Luque <spluque_at_gmail.com>
Date: Fri 09 Sep 2005 - 03:12:48 EST

Marc Bernard <bernarduse1@yahoo.fr> wrote:
> Dear All,

> I would be grateful if you can help me. My problem is the following:
> I have a data set like:

> ID time X1 X2
> 1 1 x111 x211
> 1 2 x112 x212
> 2 1 x121 x221
> 2 2 x122 x222
> 2 3 x123 x223

> where X1 and X2 are 2 covariates and "time" is the time of observation and ID
> indicates the cluster.

> I want to merge the above data by creating a new variable "X" and "type" as
> follows:

> ID time X type
> 1 1 x111 X1
> 1 2 x112 X1
> 1 1 x211 X2
> 1 2 x212 X2
> 2 1 x121 X1
> 2 2 x122 X1
> 2 3 x123 X1
> 2 1 x221 X2
> 2 2 x222 X2
> 2 3 x223 X2

> Where "type" is a factor variable indicating if the observation is related to
> X1 or X2...

Say your original data is in dataframe df, then this might do what you want:

R> newdf <- rbind(df[, 1:3], df[, c(1, 2, 4)])
R> names(newdf)[3] <- "X"
R> newdf$type <- substr(c(df[[3]], df[[4]]), 1, 2)

Cheers,

-- 
Sebastian P. Luque

______________________________________________
R-help@stat.math.ethz.ch mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
Received on Fri Sep 09 03:24:25 2005

This archive was generated by hypermail 2.1.8 : Fri 03 Mar 2006 - 03:40:05 EST