powell.powell.control(trace = 0, rhobeg = log(100)/10, rhoend = 1e-04, maxit = 1e+05, fnscale = 1, parscale = 1, ...)trace
should be set to 0, 1, 2 or 3, which controls the amount of
printing. Specifically, there is no output if trace=0 and
there is output only at the return if trace=1. Otherwise,
each new value of RHO is printed, with the best vector of variables
so far and the corresponding value of the objective
function. Further, each new value of F with its variables are output
if trace=3.fn is to
be called.fnscale less than zero implies a maximization rather
than a minimization.par.rhobeg and rhoend must be set to the initial and
final values of a trust region radius, so both must be positive with
rhoend<=rhobeg< code="">.powell