Re: [R] data manipulation

From: Martin Lam <tmlammail_at_yahoo.com>
Date: Fri 09 Sep 2005 - 03:12:30 EST


Hi,

This may not be the best solution, but at least it's easy to see what i'm doing, assume that your data set is called "data":

# remove the 4th column
data1 = data[,-4]

# remove the 3rd column
data2 = data[,-3]

# use cbind to add an extra column with only X1 #elements
data1 = cbind(data1, array("X1", nrow(data1), 1)

# use cbind to add an extra column with only X2 #elements
data2 = cbind(data2, array("X2", nrow(data2), 1)

# use rbind to add them together as rows data3 = rbind(data1, data2)

# rename the names of the columns
colnames(data3) <- c("ID", "time", "X", "type")

# show output
data3

The only thing I couldn't figure out is how to sort the data set per row, perhaps someone else could help us out on this?

Martin

> 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...
>
> Many thanks in advance,
>
> Bernard
>
>
> ---------------------------------
>
>
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>
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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 03:14:37 2005

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