randomly sample a vector from any distribution (e.g. gamma distribution)

[Kairos2012]

Hi,

help is very much appreciated. Thanks in advance!!!

rgamma(...)
As far as I know with this function (code) one can randomly sample 100 numbers simultanously.

Question: is it possible to sample 100 random numbers e.g. from 100 different gamma distributions using only one command line (or: using only one function)?

One idea how this on command line could look like:
rgamma(1:100, shape=c(s1,s2,...,s100), rate=c(r1,r2,...,r100))

What I do not know: is it correct to assume that effectively only ONE random number (with the respective paramateres s1<>s2<>...<>s100 und r1<>r2<>...<>r100) has been drawn from only ONE gamma distribution (out of 100 different gamma distributions) ?

Thanks again for any thoughts and advice!
Merry Christmas!

 

[Dason]

If all you want is a single random draw from each of the 100 gamma distributions then all you need to do is change your n to 100 (instead of 1:100).

# The first is from a gamma(1,1), the second from gamma(100, 1)
rgamma(2, c(1, 100), c(1, 1))

If you wanted to vary the number of observations from each of the gamma distributions then you could use mapply

# Grab 1 observation from gamma(6, 1,)
# grab 2 from gamma(7, 1)
# grab 3 from gamma(8, 1)
# grab 4 from gamma(9,1)
# grab 5 from gamma(10, 1)
mapply(rgamma, n = 1:5, shape = 6:10, rate = rep(1, 5))