Benford

Benford.kt

class Benford(sample: Array<BigInteger>) {
    override fun toString() = str

    private val firstDigits = IntArray(9)
    private val count = sample.size.toDouble()
    private val str: String

    init {
        for (n in sample) {
            firstDigits[n.toString().substring(0, 1).toInt() - 1]++
        }

        str = with(StringBuilder()) {
            for (i in firstDigits.indices) {
                append(i + 1).append('\t').append(firstDigits[i] / count)
                append('\t').append(Math.log10(1 + 1.0 / (i + 1))).append('\n')
            }

            toString()
        }
    }
}