A script to test the time-expense of scala.math.ulp

ulp_speed.scala

import scala.math.ulp

/**
 * ThirdWay calls `ulp` occasionally. This script tries to assess costs.
 */

def timeIt[R](f: => R): Long = {
    val start = System.currentTimeMillis
    f
    System.currentTimeMillis - start
}

val n = 1000000

val timings = (0 until n).map { i =>
    val x = i.toDouble
    timeIt { ulp(x) } 
}

val μ = timings.sum / n.toDouble
                                            // # => On my MBP mid-2012
println(s"Average timing: $μ ms")           // # => 6.9E-5 ms
println(s"Ops per second: ${1.0/μ*1000}")   // # => 1.4492753623188406E7