anchor.diff:  
       // Accessors
       let get (a:matrix) i j   = MG.get a i j
  -    let set (a:matrix) i j x = MG.set a i j x
  -        
  +    let set (a:matrix) i j x = MG.set a i j x    
       // Creation
       let init  m n f = DS.initDenseMatrixDS  m n f |> MS.dense 
       let ofList    xss   = DS.listDenseMatrixDS    xss |> MS.dense
  
positive.code:     /// computes the row specific sample covariance matrix of a data matrix 
      let rowSampleCovarianceMatrixOf (dataMatrix:Matrix<float>) =
          columnCovarianceMatrixOf (dataMatrix.Transpose.NumRows-1) dataMatrix.Transpose
  
      //----------------------------------------------------------------------------
  
  end
  
  [<AutoOpen>]
  module MatrixExtension =
  
  
negative.code:                 for rowi=0 to m.NumRows-1 do 
                  yield f (seq [for coli=0 to m.NumCols-1 do yield m.[rowi,coli]])
                  ]    
      end
  
      module MG = Generic
  