We propose a variation of simplex-downhill algorithm specifically customized for optimizing parameters in statistical machine translation (SMT) decoder for better end-user automatic evaluation metric scores for translations, such as versions of BLEU, TER and mixtures of them.
the simplex-downhill algorithm looks for a lower point by trying the reflection (line 6), expansion (line 10) and contraction (line 17) points in the order showed in the algorithm, which turned out to be very efficient.