How to shuffle a “DenseMatrix” in F#

Question

In Matlab we can write the following code to shuffle a matrix:

data = data(:, randperm(size(data,2)));

there is what I write with Math.NET:

Answer 1

@GuyCoder and @s952163, thanks for your help. I implemented a quick-and-dirty version. It is not good enough but it works.

Please feel free to comment. Thank you.

#load "../packages/FsLab.1.0.2/FsLab.fsx"
open System
open System.IO
open MathNet.Numerics.LinearAlgebra.Double
open MathNet.Numerics
open MathNet.Numerics.LinearAlgebra
open MathNet.Numerics.Distributions

// implementation of the Fisher-Yates shuffle by Mathias
// http://www.clear-lines.com/blog/post/Optimizing-some-old-F-code.aspx
let swap fst snd i =
   if i = fst then snd else
   if i = snd then fst else
   i
let shuffle items (rng: Random) =
   let rec shuffleTo items upTo =
      match upTo with
      | 0 -> items
      | _ ->
         let fst = rng.Next(upTo)
         let shuffled = List.permute (swap fst (upTo - 1)) items
         shuffleTo shuffled (upTo - 1)
   let length = List.length items
   shuffleTo items length

let csvfile = @"/eUSB/sync/fsharp/UFLDL-tutorial-F#/housing.csv"
let housingAsLines = 
    File.ReadAllLines(csvfile)
        |> Array.map (fun t -> t.Split(',')
                            |> Array.map (fun t -> float t))
let housingAsMatrix= DenseMatrix.OfRowArrays housingAsLines
let housingAsMatrixTmp = housingAsMatrix.Transpose()
let v1 = DenseVector.Create(housingAsMatrixTmp.ColumnCount,1.0)
let housingAsMatrixT = housingAsMatrixTmp.InsertRow(0,v1)

let m = housingAsMatrixT.RowCount - 1
let listOfArray = [0..m]
let random = new Random()
let shuffled = shuffle listOfArray random

let z = [for i in shuffled -> (housingAsMatrixT.[i, *])]
let final = DenseMatrix.OfRowVectors z