ets  TOL1 &lt; 0,  then  SQRT(EPS)  is used
          instead TOL1, where EPS is the machine precision
          (see LAPACK Library routine DLAMCH).
          This parameter is ignored if INIT is 'N' or 'L'.

  TOL2    DOUBLE PRECISION
          If TOL2 &gt;= 0, TOL2 is the tolerance which measures the
          relative error desired in the sum of squares, for the
          whole optimization process. Termination occurs when the
          actual relative reduction in the sum of squares is at
          mos