Sampling in which zero probabilities are removed
Sampling in which zero probabilities are removed
rng_respecting_sample(x, size, replace, prob)
x |
either a vector of one or more elements from which to choose, or a positive integer. See ‘Details.’ |
size |
a non-negative integer giving the number of items to choose. |
replace |
should sampling be with replacement? |
prob |
a vector of probability weights for obtaining the elements of the vector being sampled. |
a vector of length size with elements drawn from either x or from the integers 1:x.
thanks to Pedro Neves for finding this feature in base::sample
Richel J.C. Bilderbeek
See sample for more details
# Number of draws
n <- 1000
# Do normal sampling
set.seed(42)
draws_1 <- DDD:::rng_respecting_sample(
1:3, size = n, replace = TRUE, prob = c(1.0, 1.0, 1.0)
)
# Do a sampling with one element of probability zero
set.seed(42)
draws_2 <- DDD:::rng_respecting_sample(
1:4, size = n, replace = TRUE, prob = c(1.0, 1.0, 1.0, 0.0)
)
testit::assert(sum(draws_2 == 4) == 0)
testit::assert(draws_1 == draws_2)
# Use base sampling will give different results,
# as it results in different RNG values
set.seed(42)
draws_3 <- sample(
1:4, size = n, replace = TRUE, prob = c(1.0, 1.0, 1.0, 0.0)
)
testit::assert(sum(draws_3 == 4) == 0)
testit::assert(!all(draws_1 == draws_3))Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.