public static DenseVector UnrollMatrices(List <DenseMatrix> ThetaMatrices)
        {
            DenseVector dvRetVal = null;

            foreach (DenseMatrix Tmatrix in ThetaMatrices)
            {
                foreach (Vector <double> vec in Tmatrix.EnumerateRows())
                {
                    dvRetVal = DenseVector.OfEnumerable(dvRetVal.Concat(vec));
                }
            }
            return(dvRetVal);
        }