Thanks, that sounds like a good thing to try. But where would you specify the feature value? The numbers in the lattice format (as far as I know) are transition probability and distance to next node, so unless you can extend the list of numbers, I'm still not clear on how you incorporate the feature. Also, what weight is used, weight-i?
Suzy On 26/03/2010, at 12:30 PM, Chris Dyer wrote: > That sounds reasonable. And, I don't think you'll need to add an > extra feature to moses to do this. The lattice input format lets you > have a feature associated with a transition (in fact, I think you can > have an arbitrary number of features), so you can use that to encoded > whether the path your on corresponds to the reordered variant or not. > -Chris > > On Thu, Mar 25, 2010 at 8:51 PM, Suzy Howlett > <[email protected]> wrote: >> Hi Chris, >> >> The preprocessing I referred to is a reordering of the words of the >> source >> sentence before translation. The overall idea would be to have a >> single >> Moses model that can handle both reordered and non-reordered >> sentences. The >> only way I've thought of to do this is to combine the sentence- >> level feature >> I mentioned with two phrase translation tables and a lattice input >> combining >> the reordered and non-reordered versions of a single sentence. Then >> we could >> have a number of other features that would influence the system's >> choice of >> which version to use. There are obviously a number of points at >> which this >> scheme could break down, and I have no idea if any of it will work, >> but I >> figured the only way to find out would be to try. I appreciate any >> suggestions you have. >> >> Suzy >> >> On 26/03/2010, at 11:32 AM, Chris Dyer wrote: >> >>> Moses uses features to discriminate between alternative translations >>> of individual sentences, so if the value is constant for all >>> possible >>> translations (for example, because it is a function of the input), >>> the >>> model won't be able to take advantage of it. It sounds like you >>> might >>> be proposing something like this. What are you trying to do? >>> >>> -Chris >>> >>> On Thu, Mar 25, 2010 at 8:14 PM, Suzy Howlett >>> <[email protected]> wrote: >>>> >>>> Hi, >>>> >>>> I am just starting my foray into the world of adding features to >>>> Moses >>>> and haven't quite got my head around it yet. Could someone please >>>> check I'm on the right track, or tell me if I've overlooked an >>>> easier >>>> alternative? >>>> >>>> The feature that I want to add is essentially a sentence-level >>>> flag to >>>> say whether a given input sentence has undergone a particular >>>> kind of >>>> preprocessing before being passed to Moses. My best guess is that I >>>> need to create a file containing a look-up table to indicate which >>>> sentences have been preprocessed, e.g. >>>> >>>> <Sentence 1> ||| 0 >>>> <Sentence 2> ||| 0 >>>> <Sentence 3> ||| 1 >>>> <Sentence 4> ||| 0 >>>> ... >>>> >>>> where 1 and 0 indicate that the sentence has and has not been >>>> preprocessed, respectively. Is this the best way to do it? Does >>>> anyone >>>> know of anyone doing something similar before? >>>> >>>> I imagine I will need a StatelessFeatureFunction that will open the >>>> file and read off the value for the input sentence, and two >>>> parameters >>>> added with AddParam (one for the weight and one to specify the file >>>> containing the table above). Does that sound right so far? If >>>> anyone >>>> has any pointers for getting started implementing this feature, I'd >>>> appreciate them. >>>> >>>> Thanks, >>>> Suzy >>>> >>>> _______________________________________________ >>>> 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
