edu.neu.ccs.util
Class ProbStatTools

java.lang.Object
  extended byedu.neu.ccs.util.ProbStatTools

public class ProbStatTools
extends Object

Class ProbStatTools collects static methods that are useful for randomization, probability, and statistics.

Since:
2.3.3

Constructor Summary
private ProbStatTools()
          Prevent instantiation.
 
Method Summary
static int[] integerSequence(int n)
          Returns an array with the integers in sequence: 0, 1, etc, up to (n-1).
static int[] randomPermutation(int n)
          Returns an array whose contents is a random permutation of the integers from 0 to (n-1).
static int[] randomPermutation(int[] data)
          Returns an array whose contents is a random permutation of the contents in the data array.
static int[] repeatData(int[] data, int k)
          Returns an int array that repeats the data in the given array sequentially k times.
static int[] selectWithNoRepetition(int[] data, int k)
          Returns an array whose contents is a random selection of k elements from the contents of the given data with no repetition of a selected index.
static int[] selectWithNoRepetition(int n, int k)
          Returns an array of length k consisting of integers chosen from 0 to (n-1) with no repetition permitted.
static int[] selectWithRepetition(int[] data, int k)
          Returns an array whose contents is a random selection of k elements from the contents of the given data with repetition of a selected index permitted.
static int[] selectWithRepetition(int n, int k)
          Returns an array of length k consisting of integers chosen from 0 to (n-1) with repetition permitted.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

ProbStatTools

private ProbStatTools()
Prevent instantiation.

Method Detail

integerSequence

public static int[] integerSequence(int n)

Returns an array with the integers in sequence: 0, 1, etc, up to (n-1).

If n is less than or equal to zero, then returns an empty array of integers.


selectWithRepetition

public static int[] selectWithRepetition(int n,
                                         int k)

Returns an array of length k consisting of integers chosen from 0 to (n-1) with repetition permitted.

If n or k is less than or equal to zero, then returns an empty array of integers.


selectWithNoRepetition

public static int[] selectWithNoRepetition(int n,
                                           int k)

Returns an array of length k consisting of integers chosen from 0 to (n-1) with no repetition permitted.

If k is less than or equal to zero or greater than n, then returns an empty array of integers.


randomPermutation

public static int[] randomPermutation(int n)

Returns an array whose contents is a random permutation of the integers from 0 to (n-1).

If n is less than or equal to zero, then returns an empty array of integers.


selectWithRepetition

public static int[] selectWithRepetition(int[] data,
                                         int k)

Returns an array whose contents is a random selection of k elements from the contents of the given data with repetition of a selected index permitted.

The data array is unchanged.

If the data array is null or if k is less than or equal to zero, then returns an empty array of integers.


selectWithNoRepetition

public static int[] selectWithNoRepetition(int[] data,
                                           int k)

Returns an array whose contents is a random selection of k elements from the contents of the given data with no repetition of a selected index.

The data array is unchanged.

If the data array is null or if k is less than or equal to zero or if k is greater than the data array size, then returns an empty array of integers.


randomPermutation

public static int[] randomPermutation(int[] data)

Returns an array whose contents is a random permutation of the contents in the data array.

The data array is unchanged.

If the data array is null, then returns an empty array of integers.


repeatData

public static int[] repeatData(int[] data,
                               int k)

Returns an int array that repeats the data in the given array sequentially k times.

If the data array is null or if k is less than or equal to zero, then returns an empty array of integers.

If k equals one, then copies the given data.