Hi Andy,
You forgot a comma at the end:
people[sample(1:nrow(people), 10, replace = TRUE),]
Now it should work as expected :-)
HTH,
Jorge
On Tue, Jan 27, 2009 at 9:44 PM, Andy <andy.choens@gmail.com> wrote:
> I would like to create a random sample of the rows of a data frame that
> is larger than the number of rows in the data frame. With an individual
> vector, this is easy using select(variable, number, replace = TRUE). I
> looked on-line I found some guides to sample from a data frame using
> indexing, but I don't seem to be able to get the results that I want.
>
> # Example:
> name <- c("andy", "kevin", "lindsay",
"karen")
> age <- c(29, 37, 26, 31)
> gender <- c("M", "M", "F", "F")
> people <- data.frame(name, age, gender)
>
> # I would like to create a random sample of my rows, N =10
> people[sample(1:nrow(people), 10, replace = TRUE)]
>
> Sometimes this generates an error (undefined columns), and sometimes it
> creates a random selection (N=10) of my columns, not my rows. This lead
> me to try:
>
> people[sample(1:ncol(people), 10, replace = TRUE)]
> #AND
> people[sample(people, 10, replace = TRUE)]
>
> Neither works. Could someone please explain to me what I am missing?
>
> I feel like I am close because this does work:
>
> counts <- 1:10
> counts[sample(counts, 20, replace = TRUE)]
>
>
> Thank you
> --andy
>
> System Info
>
> platform i486-pc-linux-gnu
> arch i486
> os linux-gnu
> system i486, linux-gnu
> status
> major 2
> minor 7.1
> year 2008
> month 06
> day 23
> svn rev 45970
> language R
> version.string R version 2.7.1 (2008-06-23)
>
> --
> This is the price and the promise of citizenship.
> -- Barack Obama, 44th President of the United States
>
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