public MatrixR LUInverse(MatrixR m)
        {
            int     n = m.GetRows();
            MatrixR u = m.Identity();

            LUDecompose(m);
            VectorR uv = new VectorR(n);

            for (int i = 0; i < n; i++)
            {
                uv = u.GetRowVector(i);
                LUSubstitute(m, uv);
                u.ReplaceRow(uv, i);
            }
            MatrixR inv = u.GetTranspose();

            return(inv);
        }