for (int i = 0; i < xx.Length; i++)
            {
                kolejne = 1;
                ptg = 1;
                if (i < 4) {
                for (int j = 1; j < dlugosc-1; j++)
                {
                    wsp[i, j] = Math.Pow(xx[i], ptg);
                    if (ptg < 3)
                        ptg++;

                    if (j >= 4)
                    {
                        wsp[i, j] = Math.Pow(xx[i] - xx[kolejne], 3);
                        if (kolejne <= xx.Length -1)
                            kolejne++;
                    }

                }
                            }
                else
                {
                    for (int j = 1; j < dlugosc; j++)
                    {
                        wsp[i, j] = Math.Pow(xx[i], ptg);
                        if (ptg < 3)
                            ptg++;

                        if (j >= 4)
                        {
                            wsp[i, j] = Math.Pow(xx[i] - xx[kolejne], 3);
                            if (kolejne <= xx.Length - 1)
                                kolejne++;
                        }

                    }
                }