fill a list with numbers drawn from an exponential distribution

Main.kt

import kotlin.math.ln

fun main() {
    // a specified mean for an exponential
    // distribution of random numbers
    val specifiedMean = 3.0

    // create a random number generator
    val rng = kotlin.random.Random(System.nanoTime())

    // define a function that creates a function
    //   * rng.nextDouble() returns a random number
    //     in [0.0, 1.0) with equal probability of
    //     drawing any number in the range
    //     (it draws from a uniform distribution)
    //   * -mean * ln(rng.nextDouble()) returns a
    //     random number drawn from an exponential
    //     distribution with the specified mean
    //     (the number will be non-negative, has
    //     no upper bound, and is more likely to
    //     be small than large)
    //
    // * makeExpRNG is a function with one floating
    //   point parameter
    // * makeExpRNG returns a function that has one
    //   integer parameter
    // * the function that makeExpRNG returns in turn
    //   returns a random number drawn from an
    //   exponential distribution
    // * the right-hand side of this assignment is
    //   a lambda that returns a lambda1
    val makeExpRNG =
        { mean:Double -> { n:Int -> -mean * ln(rng.nextDouble()) }}

    // create the random number generator function
    // to use in filling a list with random numbers
    //
    // expRng is a function with one integer parameter
    // that returns a floating point value to its caller
    //
    // it is not necessary to include the type of
    // expRNG explicitly---the Kotlin compiler can
    // infer the type---I have included it here to
    // help the reader see more clearly what is
    // happening
    val expRNG: (Int) -> Double = makeExpRNG( specifiedMean )

    // create a list of 1024 random numbers,
    // each drawn from an exponential distribution
    // with a specified mean
    //
    // * expRNG is a function whose one parameter
    //   is an integer.
    // * that integer will be the index of an
    //   element of the list
    // * in this case, the function does nothing
    //   with the index
    // * for each index, the function returns
    //   a random number drawn from an exponential
    //   distribution with a specified mean
    val data = List<Double>(1024, expRNG )

    // * we expect that that smallest number
    //   in the list will be very close to zero
    // * we expect that the largest number
    //   in the list will be larger than the
    //   specified mean
    // * we expect that the mean to be very
    //   nearly equal to the specified mean
    val min = data.minOrNull()
    val max = data.maxOrNull()
    val mean = data.average()

    println("minimum = $min")
    println("maximum = $max")
    println("mean = $mean")
} // main()