Perhaps I've missed it but I don't believe Numerics has a create random permutation function.
I've had need of randomly permuting columns/rows in matrices and so I wrote this short little function to create the random permutations.
It is an implementation of the FisherYates shuffle.
Public Function RandPermutation(ByVal length As Integer) As Permutation
'This function returns a random permutation mapping of length 'length'.
'For use in the permute rows/columns matrix functions
Randomize()
Dim series(length  1) As Integer
Dim randint, temp As Integer
For x = 0 To length  1
series(x) = x
Next
For i = length  1 To 1 Step 1
randint = Int(Rnd() * (i) + 0.5)
temp = series(i)
series(i) = series(randint)
series(randint) = temp
Next
Return Permutation.FromInversions(series)
End Function
It is nice that you can store this permutation and then use it again for another matrix.
For example if you have 2 matrices with corresponding rows/columns you can permute each with the same permutation and the matrices will still correspond.
This is useful for me in that I have matrices of input variables and corresponding matrices of target values. When doing minibatch gradient descent I can use the random permutation function without losing the correspondence between input and target.
