Sampling with and without replacement
I seem unable to use "replace = F" when I want to sample without
replacement. I would think
that it comes down to "F is not a legitimate abbreviation for FALSE."
except that
Dalgaard (p. 118) uses F for FALSE and it works
"pairwise.t.test(folate, ventilation, pool.sd = F)"
I am having trouble when I try to sample a vector without replacement.
The following code illustrates my problem.
>b <- c(1:8)
>sample(b)
[1] 7 8 3 5 1 6 2 4 # That works correctly--no replacement
(This would be my preferred form, but when I look at the code later it
is helpful to know
explicitly how I did the sampling.)
> sample(b, replace = T)
[1] 7 5 6 2 5 5 4 7 # That is also correct--replacement
> sample(b, replace = F)
[1] 1 7 3 7 3 4 6 5 # There are two 3s and two 7s, so there was
replacement
>sample(b, replace = FALSE)
[1] 8 1 3 2 5 6 7 4 # That works just fine
>sample(b, replace = "F")
[1] 5 3 2 8 4 1 7 6 # quoting the F is fine.
If it is OK to replace TRUE with T, why can't I replace FALSE with F?
I have a similar problem if I write data <= read.table(file.choose(),
header = F)
I'm using a Windows machine with version 2.8.0, but I'm sure that this
is not a machine specific problem.
Thanks,
Dave Howell
--
David C. Howell
PO Box 770059
627 Meadowbrook Circle
Steamboat Springs, CO
80477
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