Before revision:  If the frequency surrogates are constructed by minimal rational interpolation , frequency and parameters can both be sampled in a greedy fashion, by employing a fully non-intrusive "look-ahead" strategy.
After revision:  If the frequency surrogates are constructed by a suitable rational interpolation strategy , frequency and parameters can both be sampled in a greedy fashion, by employing a fully non-intrusive "look-ahead" strategy.