Performance comparison

gistfile1.txt

/**
 * populate n * n @Double array
 * using math.random
 */
object FillingAnArray extends App {
  println("in scala")
  for (x <- 1 to 3) {
    val l: Int = Math.pow(10, x).toInt
    val startTime = Double.valueOf(System.currentTimeMillis())
    val random = new Random()
    val n = l
    val array = Array.ofDim[Double](n, n)
    for (x <- 0 to n - 1; y <- 0 to n - 1) {
      array(x)(y) = random.nextDouble()
    }
    val stoptime = Double.valueOf(System.currentTimeMillis())
    println(l + "," + (stoptime - startTime))
  }

}

// sample outcome of above program
// in scala
// 10,4.0
// 100,11.0
// 1000,82.0

public class FillingAnArrayJava {

	public static void main(String[] args) {
		System.out.println("in java");
		for (int i = 1; i <= 3; i++) {
			int n = Double.valueOf(Math.pow(10, i)).intValue();
			double startTime = Double.valueOf(System.currentTimeMillis());
			Random random = new Random();
			Double array[][] = new Double[n][n];
			for (int x = 0; x < n - 1; x++) {
				for (int y = 0; y < n - 1; y++) {
					array[x][y] = random.nextDouble();
				}
			}
			double stoptime = Double.valueOf(System.currentTimeMillis());
			System.out.println(n + " ," + (stoptime - startTime));
		}
	}
}

// sample output of above program
// in java
// 10 ,0.0
// 100 ,11.0
// 1000 ,88.0