Hi:
Try this:
# Function to generate one sample from the data frame
sampler <- function(df) {
s1 <- sample(nrow(df), 1, replace = FALSE)
s2 <- sample(setdiff(1:nrow(df), s1), 2, replace = FALSE)
list(sample1 = df[s1, grep('^C', names(df))],
sample2 = df[s2, grep('^W', names(df))])
}
sampler(mydf) # try it out on your data frame below
# replicate the process 1000 times
l <- vector('list', 1000)
for(i in seq_along(l)) l[[i]] <- sampler(mydf)
HTH,
Dennis
On Tue, Nov 16, 2010 at 9:53 AM, wangwallace <talentt...@gmail.com> wrote:
>
> Fabulicious!!!!!!!!!!!!!!!!! It worked!!!
>
> One more question, in the following data frame as posted above:
>
> SubID CSE1 CSE2 CSE3 CSE4 WSE1 WSE2 WSE3 WSE4
> 1 6 5 6 2 6 2 2 4
> 2 6 4 7 2 6 6 2 3
> 3 5 5 5 5 5 5 4 5
> 4 5 4 3 4 4 4 5 2
> 5 5 6 7 5 6 4 4 1
> 6 5 4 3 6 4 3 7 3
> 7 3 6 6 3 6 5 2 1
> 8 3 6 6 3 6 5 4 7
>
> I want to draw the first random sample consisting of a row of integers
> under
> the first group of variables (CSE1, CSE2, CSE3, CSE4). For example,
> assuming
> the first draw yielded a sample of the first row (6, 5, 6, 2), now I want
> to
> draw another random sample consisting of two rows of integers under the
> second group of variables (WSE1, WSE2, WSE3, WSE4). Also, for the second
> draw, I want to restrict a vector I am going to sample from to only those
> rows that are not correspond to SubID I have sampled. That is, I want to
> sample two rows of integers under the second group of variables (WSE1,
> WSE2,
> WSE3, WSE4) from rows 2, 3, 4, 5, 6, 7, and 8.
>
> Also, I want to repeat this whole process (drawing 1 random row of integers
> under the first group of variables first, AND then another two random rows
> under the second group of variables) for 1000 times. Any ideas? would that
> be possible to do it by just revising the syntax you wrote above? many
> thanks!!!
> --
> View this message in context:
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> Sent from the R help mailing list archive at Nabble.com.
>
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