Class Permutations

java.lang.Object
org.jblas.util.Permutations

public class Permutations extends Object
Functions which generate random permutations.
Author:
Mikio L. Braun
  • Constructor Details

  • Method Details

    • 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]