Constructor Detail

• Permutations

  public Permutations()

Method Detail

• randomPermutation

  public static int[] randomPermutation​(int size)

  Create a random permutation of the numbers 0, ..., size - 1. see Algorithm P, D.E. Knuth: The Art of Computer Programming, Vol. 2, p. 145

• randomSubset

  public static int[] randomSubset​(int k,
                                   int n)

  Get a random sample of k out of n elements. See Algorithm S, D. E. Knuth, The Art of Computer Programming, Vol. 2, p.142.

• permutationDoubleMatrixFromPivotIndices

  public static DoubleMatrix permutationDoubleMatrixFromPivotIndices​(int size,
                                                                     int[] ipiv)

  Create a permutation matrix from a LAPACK-style 'ipiv' vector.

  Parameters:

  ipiv - row i was interchanged with row ipiv[i]

• permutationFloatMatrixFromPivotIndices

  public static FloatMatrix permutationFloatMatrixFromPivotIndices​(int size,
                                                                   int[] ipiv)

  Create a permutation matrix from a LAPACK-style 'ipiv' vector.

  Parameters:

  ipiv - row i was interchanged with row ipiv[i]