[R] help with simple but massive data transformation

[ONKELINX, Thierry]

This should be easy with apply()

do.call(rbind, apply(dataset, 1, function(x){
	list(data.frame(startend = x[1]:x[2], value = x[3])
}))

Untested!

------------------------------------------------------------------------
----
ir. Thierry Onkelinx
Instituut voor natuur- en bosonderzoek
team Biometrie & Kwaliteitszorg
Gaverstraat 4
9500 Geraardsbergen
Belgium

Research Institute for Nature and Forest
team Biometrics & Quality Assurance
Gaverstraat 4
9500 Geraardsbergen
Belgium

tel. + 32 54/436 185
Thierry.Onkelinx op inbo.be
www.inbo.be

To call in the statistician after the experiment is done may be no more
than asking him to perform a post-mortem examination: he may be able to
say what the experiment died of.
~ Sir Ronald Aylmer Fisher

The plural of anecdote is not data.
~ Roger Brinner

The combination of some data and an aching desire for an answer does not
ensure that a reasonable answer can be extracted from a given body of
data.
~ John Tukey
  

> -----Oorspronkelijk bericht-----
> Van: r-help-bounces op r-project.org 
> [mailto:r-help-bounces op r-project.org] Namens clee
> Verzonden: maandag 11 oktober 2010 16:17
> Aan: r-help op r-project.org
> Onderwerp: [R] help with simple but massive data transformation
> 
> 
> I have data that looks like this:
> 
> start     end     value
> 1          4         2
> 5          8         1  
> 9         10        0
> 
> 
> I want to transform the data so that it becomes:
> 
> startend     value
> 1               2
> 2               2
> 3               2
> 4               2
> 5               1
> 6               1
> 7               1
> 8               1
> 9               0
> 10             0
> 
> ----
> I've written a for loop that can do the transformation BUT I 
> need to do this on very large datasets (millions of rows).  
> Does anyone know of an R package that has a function that can 
> do this transformation?
> 
> Any help is much appreciated!
> 
> Thanks!
> --
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> a-transformation-tp2989850p2989850.html
> Sent from the R help mailing list archive at Nabble.com.
> 
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