[R] Simple but elusive - expand back from counts

[Peter Alspach]

Tena koe

Try something like:

tmp[rep(1:nrow(tmp), each=tmp[,4]),] # untested

HTH ...

Peter Alspach

> -----Original Message-----
> From: r-help-bounces at r-project.org [mailto:r-help-bounces at r-
> project.org] On Behalf Of jjap
> Sent: Wednesday, 30 March 2011 7:16 a.m.
> To: r-help at r-project.org
> Subject: [R] Simple but elusive - expand back from counts
> 
> Dear R-users,
> 
> This should be simple but still eludes me:
> 
> Given the following
> tmp<-as.data.frame(matrix(c(44, 10, "abc", 1, 44, 10, "def", 1, 44, 12,
> "abc", 2), 3, 4, byrow=T))
> 
> I want to  expand the data to the following form:
> 
>   V1 V2  V3 V4
> 1 44 10 abc  1
> 2 44 10 def  1
> 3 44 12 abc  1
> 4 44 12 abc  1
> 
> The last row of the original df was duplicated the row by the number in
> the
> 4th column (which could be expendable being all ones)
> I clumsily tried a few variants of a loop but I am not making any
> progress.
> Any hints would be greatly appreciated.
> for (i in 1:3){
>   rbind(rep(tmp[i,], temp[i,4])
>   }
> 
> --
> View this message in context: http://r.789695.n4.nabble.com/Simple-but-
> elusive-expand-back-from-counts-tp3415727p3415727.html
> Sent from the R help mailing list archive at Nabble.com.
> 
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> and provide commented, minimal, self-contained, reproducible code.

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