Is this what you want:
> x <- read.table(text = "ColumnA ColumnB ColumnC
+ a d d
+ s s e
+ e r e
+ y w y
+ t u i
+ q e l", as.is = TRUE, header =
TRUE)> x$ColumnC[1:3] <- runif(3)
> x
ColumnA ColumnB ColumnC
1 a d 0.965288798790425
2 s s 0.722888228250667
3 e r 0.634451690129936
4 y w y
5 t u i
6 q e l>
Now ColumnC is character, so the random numbers are character strings.
What is the problem you are trying to solve?
On Wed, Feb 15, 2012 at 4:38 AM, Camilo Mora <cmora at dal.ca>
wrote:> Hi:
> I wonder if anyone may know the answer to this question:
>
> COnsider the following data frame (DF):
>
> ColumnA ? ColumnB ? ColumnC
> ?a ? ? ? ? d ? ? ? ? d
> ?s ? ? ? ? s ? ? ? ? e
> ?e ? ? ? ? r ? ? ? ? e
> ?y ? ? ? ? w ? ? ? ? y
> ?t ? ? ? ? u ? ? ? ? i
> ?q ? ? ? ? e ? ? ? ? l
>
> What I need is to replace rows 1 to 3 in ColunmC for a random number?
> I tried DF$ColumnC[DF$ColumnC [1:3]] <- .Random.seed[1:3]
> but does not work.
>
> It may be trivial but have not been able to find a solution.
>
> Thanks,
> Camilo
>
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--
Jim Holtman
Data Munger Guru
What is the problem that you are trying to solve?
Tell me what you want to do, not how you want to do it.