
<I>ftol</I> is a nonnegative input variable. Termination
occurs when both the actual and predicted relative
reductions in the sum of squares are at most <I>ftol</I>.
Therefore, <I>ftol</I> measures the relative error desired
in the sum of squares.
<P>
<I>xtol</I> is a nonnegative input variable. Termination
occurs when the relative error between two consecutive
iterates is at most <I>xtol</I>. Therefore, <I>xtol</I> measures the
relative error desired in the approximate solution.
<P>
<I>gtol</I> is a nonne