Mert procedure of Moses provides an option called "--activate-features" which performs something similar to the opposite of what you need.
--activate-features=STRING ... comma-separated list of features to work on (if undef work on all features), others are fixed to the starting values (or better to their ratios) You can specify one or more features to estimate, keeping the others fixed, in the sense that their their ratios are fixed. In other word, this option groups the "not-active" features into one virtual new feature which is weighted as usual together with the "active" ones. But, considering that mert provides normalization of the weights at each iteration, this option can not be used to fix just one weight. Your request is also not well-defined because any set of weights can be proportionally augmented or reduced to give one of them always the same value, without changing the output of the decoder: multiplying all feature weights by a constant value does not modify the translations, but only their scores by the same constant factor. For instance, if you want to fix the LM (lm) and the word penalty (w), you can activate the translation model (tm) and the distortion model (d) you have to run mert with this --activate-feaures tm,d where features are specified with their short names. best, Nicola On 7/16/09 6:02 PM, "Marta Ruiz" <[email protected]> wrote: Dear all, I was optimizing with mert-moses-new.pl and I wonder how I can fix a lambda to one specific value and keep that value fix during all the optimization. Thanks in advance, Marta _______________________________________________ Moses-support mailing list [email protected] http://mailman.mit.edu/mailman/listinfo/moses-support _______________________________________________ Moses-support mailing list [email protected] http://mailman.mit.edu/mailman/listinfo/moses-support
