[R] combining vectors to matrices or data frames

Renaud Lancelot
Wed, 15 May 2002 16:17:15 -0000

use list and do.call:

MyList <- list()

for(i in 1:5]){
  #some calculations for a,b,c,d,e
  a<- ... b<- ... c<- .. ....
  MyList[[i]] <- c(a,b,c,d,e)
  }

MyData <- do.call("rbind", MyList)

will work fro relatively small ( < 1000, say) values of i. Otherwise,
other solutions will be quicker.

Best,

Renaud

Jan Malte Wiener wrote:
>
> hi,
>
> during a for(i in 1:xx]) loop I always newly calculate a vector
> (e.g. tmp<-c(a,b,c,d,e) )
> now i need that vector to be attached at the bootom of a matrix (or
> data.frame).
>
> e.g.
>
> m<-matrix()
>
> for(i in 1:5]){
>         #some calculations for a,b,c,d,e
>         a<- ... b<- ... c<- .. ....
>
>         tmp<-c(a,b,c,d,e)
>
>         ??? now I need to attach this tmp to the matrix m ???
> }
>
> i couldn't get rbind or append to work properly
>
> thanks for advice,
> jan
>
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--
Dr Renaud Lancelot, v?t?rinaire
CIRAD, D?partement Elevage et M?decine V?t?rinaire (CIRAD-Emvt)
Programme Productions Animales
http://www.cirad.fr/presentation/programmes/prod-ani.shtml (Fran?ais)
http://www.cirad.fr/presentation/en/program-eng/prod-ani.shtml (English)

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