PermuteArray (ejml-experimental 0.39 API)

java.lang.Object
- org.ejml.dense.row.misc.PermuteArray

```
public class PermuteArray
extends java.lang.Object
```
Generates a permutations of an integer set from 0 to N-1. This can either be generated all at once as a list of one at a time.

Constructor Summary

Constructors
Constructor Description

PermuteArray(int N)

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`static java.util.List<int[]>`	`createList(int N)`	Creates a list of all permutations for a set with N elements.
`static int`	`fact(int N)`	Computes N factorial
`int[]`	`next()`	Creates the next permutation in the sequence.
`int`	`sgn()`	Returns signature of the permutation.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - PermuteArray
```
public PermuteArray(int N)
```
- Method Detail
  - sgn
```
public int sgn()
```
    Returns signature of the permutation. This is the sgn() operator and returns -1 or 1 depending on it being odd or even.
    sgn(σ) = ( − 1)^m
    
    where m is the number of inversions.
    
    NOTE: This implementation is painfully slow O(N!). There is probably another algorithm out there which is much faster.
    
    Returns:
    
    -1 or 1 for odd or even permutations.
  - fact
```
public static int fact(int N)
```
    Computes N factorial
  - createList
```
public static java.util.List<int[]> createList(int N)
```
    Creates a list of all permutations for a set with N elements.
    
    Parameters:
    
    N - Number of elements in the list being permuted.
    
    Returns:
    
    A list containing all the permutations.
  - next
```
public int[] next()
```
    Creates the next permutation in the sequence.
    
    Returns:
    
    An array containing the permutation. The returned array is modified each time this function is called.