[R] reshaping a dataset for a network

[Marco Guerzoni]

Thank you fro the reply.
I managed to arrive till here, then I would like to have it in matrix 
where the $1 $2...$5 are the first column.

Il 3/13/2012 8:15 PM, William Dunlap ha scritto:
> Is the following what you want?
>    >  a<- c(1,2,3,4,4,4,5,5)
>    >  b<- c(11,7,4,9,8,3,12,4)
>    >  split(b, a)
>    $1
>    [1] 11
>
>    $2
>    [1] 7
>
>    $3
>    [1] 4
>
>    $4
>    [1] 9 8 3
>
>    $5
>    [1] 12  4

Here I did

c <- split(b, a)
d <- do.call(rbind,c)

and I get

   [,1] [,2] [,3]
1   11   11   11
2    7    7    7
3    4    4    4
4    9    8    3
5   12    4   12


Instead of what I would like:

   [,1] [,2] [,3]
1   11
2    7
3    4
4    9    8    3
5   12    4

A solution could be rbind.fill , which does not seem to work with list.


thanks
Marco Guerzoni,
Department of Economics
University of Turin


>
> Note that your df<-cbind(a,b) produces a matrix, not the data.frame
> that your df suggests you want.  Use df<-data.frame(a,b) to make
> a data.frame.  Then you could do with(df, split(a,b)) to operate on
> the a and b in the data.frame df.
>
> Bill Dunlap
> Spotfire, TIBCO Software
> wdunlap tibco.com
>
>
>> -----Original Message-----
>> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] On Behalf
>> Of Marco Guerzoni
>> Sent: Tuesday, March 13, 2012 10:51 AM
>> To: r-help at r-project.org
>> Subject: [R] reshaping a dataset for a network
>>
>> dear all,
>> apologizes for bothering with a probably stupid question but I really
>> don' t know how to proceed.
>>
>> I have a dataset which look like df
>>
>> a<- c(1,2,3,4,4,4,5,5)
>> b<- c(11,7,4,9,8,3,12,4)
>> df<-cbind(a,b)
>>
>> I would like to have one which looks like this:
>>
>> a
>> 1 11
>> 2 7
>> 3 4
>> 4 9 8 3
>> 5 12 4
>>
>> a are vertex of a network, b the edges. In the data the lenght of a is
>> about 50000
>>
>> I read several posts about reshape, reshape2, split, ldply but I
>> couldn't manage to do it. The problem seems to be that the is not a real
>> panel.
>>
>> Any help would be really appreciated,
>> my best regards
>> Marco
>>
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