randI {round}

Random Integers of Specified Number of Digits

Description

Create n random integer valued numbers all with a specified number of digits d.

Usage

randI(n, d)

Arguments

n

numeric sample size, i.e., length() of result.

d

a positive integer, giving the exact number of digits the resulting numbers must have.

Details

This is based on runif() and not sample(), which for now also makes it less R version dependent.

Value

A numeric vector of length n of numbers N where each N has exactly d digits; equivalently,

10^{d-1} \le N_i < 10^d,

and every N_i appears with the same probability 1 / (9\cdot 10^{d-1})

Author(s)

Martin Maechler

See Also

Uniform random numbers runif; Random number generators, seeds, etc: RNG.

Examples

plot(
 T2 <- table(randI(1e6, 2))) ; abline(h = 1e6 / (9*10^(2 - 1)), lty=2, col="gray70")
chisq.test(T2) # typically not at all significant
T3 <- table(randI(1e6, 3))
chisq.test(T3)
stopifnot(exprs = {
  identical( 10:99 , as.integer(names(T2)))
  identical(100:999, as.integer(names(T3)))
})