[R] How to replace range of data in a dataframe

[jim holtman]

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.