Re: [R] Concatenating data frame

From: jim holtman <jholtman_at_gmail.com>
Date: Thu 11 May 2006 - 09:02:15 EST

Put the intermediate results in a list and then use do.call:

result <- list()
for (i in 1:100){

    result[[i]] <- data.frame(id=sample(letters,1), value=i) }
newDataFrame <- do.call('rbind', result)

On 5/10/06, Charles Cheung <boom2k1@hotmail.com> wrote:
>
> Hello, I have searched through the R-help archive and find that the
> easiest
> way to concatenate data records in a dataframe is to use rbind()
>
>
> I know we can do that using rbind, but it is slow when we are doing rbind
> thousands of times to a growing list, each time adding one or two records
> to
> the ever growing existing data because in
>
> existingRecords<-rbind(existingRecords, aNewRecordToBeAdded),
>
> I am making a copy of the data each time rbind is called!
>
> Is there a way to avoid these data copying?
>
>
> Thank you in advance!
>
> Charles
>
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--
Jim Holtman
Cincinnati, OH
+1 513 646 9390 (Cell)
+1 513 247 0281 (Home)

What the problem you are trying to solve?

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Received on Thu May 11 09:13:41 2006

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