[R] how to merge panel data stored by variable?

[hadley wickham]

On Wed, Dec 10, 2008 at 1:54 PM, Viktor Nagy <viktor.nagy at gmail.com> wrote:
> 2008/12/10 Stefan Grosse <singularitaet at gmx.net>
>>
>> > I have two datasets stored in tab-separated format in the following way
>> > file1:
>> > country           year1        year2
>> > Germany        var1          var1
>> > Hungary         var1          var1
>> >
>> > file2:
>> > country           year1        year2
>> > Germany        var2         var2
>> > Hungary         var2         var2
>> >
>> > I can easily read in these files, but how can I merge them as a panel
>> > dataset?
>> >
>> >
>>
>> ?cbind
>> ?rbind
>>
>
> Thanks for your answer Stefan, but I think cbind/rbind does not solve
> my problem.
>
> After reading ?cbind I realised that first I should convert all the
> dataset to panel separately, and then I will be able to cbind/rbind
> it.
>
> So the question is how to read in the following data from a file as a
> panel dataset
>
> country           year1        year2
> Germany        var1          var1
> Hungary         var1          var1
>
> that is to have:
> country        year      var1
> Germany      year1    value1
> Germany      year2    value1
> Hungary       year1    value1
> Hungary       year2    value1

Have a look at melt in the reshape package, http://had.co.nz/reshape.

melt(mydf, id = "country")

should do what you want.

Hadley

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