Package smile.math

Class Random

  • public class Random
extends java.lang.Object
    This is a high quality random number generator as a replacement of the standard Random class of Java system.
    Author:
    Haifeng Li

    • Constructor Summary

      Constructors 
      Constructor Description
      Random()
      Initialize with default random number generator engine.
      Random​(long seed)
      Initialize with given seed for default random number generator engine.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      double nextDouble()
      Generator a random number uniformly distributed in [0, 1).
      double nextDouble​(double lo, double hi)
      Generate a uniform random number in the range [lo, hi)
      void nextDoubles​(double[] d)
      Generate n uniform random numbers in the range [0, 1)
      void nextDoubles​(double[] d, double lo, double hi)
      Generate n uniform random numbers in the range [lo, hi)
      int nextInt()
      Returns a random integer.
      int nextInt​(int n)
      Returns a random integer in [0, n).
      long nextLong()  
      void permutate​(double[] x)
      Generates a permutation of given array.
      void permutate​(float[] x)
      Generates a permutation of given array.
      int[] permutate​(int n)
      Generates a permutation of 0, 1, 2, ..., n-1, which is useful for sampling without replacement.
      void permutate​(int[] x)
      Generates a permutation of given array.
      void permutate​(java.lang.Object[] x)
      Generates a permutation of given array.
      void setSeed​(long seed)
      Initialize the random generator with a seed.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • Random

        public Random()
        Initialize with default random number generator engine.

      • Random

        public Random​(long seed)
        Initialize with given seed for default random number generator engine.

    • Method Detail

      • nextDouble

        public double nextDouble()
        Generator a random number uniformly distributed in [0, 1).
        Returns:
        a pseudo random number

      • nextDoubles

        public void nextDoubles​(double[] d)
        Generate n uniform random numbers in the range [0, 1)
        Parameters:
        d - array of random numbers to be generated

      • nextDouble

        public double nextDouble​(double lo,
                         double hi)
        Generate a uniform random number in the range [lo, hi)
        Parameters:
        lo - lower limit of range
        hi - upper limit of range
        Returns:
        a uniform random real in the range [lo, hi)

      • nextDoubles

        public void nextDoubles​(double[] d,
                        double lo,
                        double hi)
        Generate n uniform random numbers in the range [lo, hi)
        Parameters:
        lo - lower limit of range
        hi - upper limit of range
        d - array of random numbers to be generated

      • setSeed

        public void setSeed​(long seed)
        Initialize the random generator with a seed.

      • nextInt

        public int nextInt()
        Returns a random integer.

      • nextInt

        public int nextInt​(int n)
        Returns a random integer in [0, n).

      • nextLong

        public long nextLong()

      • permutate

        public int[] permutate​(int n)
        Generates a permutation of 0, 1, 2, ..., n-1, which is useful for sampling without replacement.

      • permutate

        public void permutate​(int[] x)
        Generates a permutation of given array.

      • permutate

        public void permutate​(float[] x)
        Generates a permutation of given array.

      • permutate

        public void permutate​(double[] x)
        Generates a permutation of given array.

      • permutate

        public void permutate​(java.lang.Object[] x)
        Generates a permutation of given array.