test performance of breeze abs(v) vs v.map(Math.abs(_))

absTest.scala

import breeze.linalg.{Vector => BV, DenseVector => DBV}
import breeze.numerics.abs

def absTest(n: Int = 1000, m: Int = 10) {
  var start = System.currentTimeMillis()
  val vectors = (1 to n).toArray.map(i => DBV((1 to m).toArray.map(j => -1.0 + (2.0 * Math.random()))))
  var end = System.currentTimeMillis()
  println(s"Time for Creating: ${end - start}")

  start = System.currentTimeMillis()
  vectors.map(v => abs(v))
  end = System.currentTimeMillis()
  println(s"Time for mapping breeze.numerics.abs: ${end - start}")

  start = System.currentTimeMillis()
  vectors.map(v => v.map(x => Math.abs(x)))
  end = System.currentTimeMillis()
  println(s"Time for mapping Math.abs: ${end - start}")
}

results.txt

scala> absTest(n = 1000000, m = 10)
Time for Creating: 1471
Time for mapping breeze.numerics.abs: 622
Time for mapping Math.abs: 1255