equired of the objective
function at the solution.  If the absolute difference between the
error functions between two successive steps is less than
<CODE>options(3)</CODE>, then this condition is satisfied.
Both this and the previous condition must be
satisfied for termination. Note that testing the function value at each
iteration roughly halves the speed of the algorithm.

<p><CODE>options(5)</CODE> determines whether the patterns are sampled randomly
with replacement. If it is 0 (the default), then patt