HLG EOTF

#!/usr/bin/env groovy

int range = 940 - 64;

for (r in 0..range) {

    def e = (double)r / (double)range;
    def o = new BigDecimal(eotf(e))

    println("${r + 64}: ${o.toPlainString()}")
}

double eotf(double o) {

    def y = ioetf(o)

    return 1_000.0 * Math.pow(y, 1.2 - 1.0) * y
}

double ioetf(double e) {

    return e < 0.5 ? Math.pow(e, 2.0) / 3.0 : (Math.exp(((e - 0.55991073) / 0.17883277)) + 0.28466892) / 12
}