nsamp {prob} | R Documentation |
Calculates the number of samples from an urn under different sampling scenarios.
nsamp(n, k, replace = FALSE, ordered = FALSE)
n |
an integer or integer vector. |
k |
an integer or integer vector. |
replace |
logical indicating whether sampling should be done with replacement. |
ordered |
logical indicating whether order among samples is important. |
The nsamp()
function will calculate the number of samples from an urn under assorted assumptions on the sampling procedure. The arguments are: n
, the number of (distinguishable) objects in the urn, k
, the sample size, and replace
, ordered
as documented in urnsamples
.
nsamp()
is vectorized, so that entering vectors instead of numbers for n
, k
, replace
, and ordered
results in a vector of corresponding answers.
The formulas used in the four possible combinations of replace
and ordered
are as follows.
replace = TRUE
and ordered = TRUE
, the value is n^k.
replace = FALSE
and ordered = TRUE
, the value is
n!/(n-k)!.
replace = FALSE
and ordered = FALSE
, the value is
n!/[k!(n-k)!].
replace = TRUE
and ordered = FALSE
, the value is
(n-1+k)!/[(n-1)!k!].
A number.
G. Jay Kerns gkerns@ysu.edu.
nsamp(n=3, k=2, replace = TRUE, ordered = TRUE) nsamp(n=3, k=2, replace = TRUE, ordered = FALSE) nsamp(n=3, k=2, replace = FALSE, ordered = FALSE) nsamp(n=3, k=2, replace = FALSE, ordered = TRUE)