There are a few kinds of pruning in syntactic decoding: -ttable-limit sets the max number of target side rules per source rule.
-cube-pruning-pop-limit controls the beam size aka pop limit even if the algorithm isn't cube pruning. Default 1000. I think the parser can also throw out entire source side matches. This is disabled by default; ask Phil Williams about it. Kenneth On 06/18/13 12:36, Per Tunedal wrote: > Hi, > Is histogram pruning always on? What's the default stack size? Why isn't > it listed among the settings on the Syntax Tutorial page? > > How is the search and pruning actually done for hierarchical models? > When is the histogram pruning done? > > I've tested with the settings: > moses_chart -f trainTreeSyntaxInSourceAndTarget/model/moses.ini < > fr-sv.test.fr > fr-sv.test.fr.TreeSyntaxInSourceAndTarget.translated 2> > stderrTreeSyntaxInSourceAndTarget.txt > > I suppose I got the default cube-pruning-pop-limit 1000, but what about > the histogram pruning? I've read that the stack size isn't much of a > problem when using cube pruning (Advanced Features page). > > BTW The results are very disappointing. > > Yours, > Per Tunedal > > PS I've read a lot of books and papers on the subject but got lost in > the details. A very simplified explanation with the main steps for the > implementation in Moses would be helpful. > > On Tue, Jun 18, 2013, at 17:08, Hieu Hoang wrote: >> there is historgram pruning in the chart decoder. It's implemented in >> ChartHypothesisCollection::PruneToSize() >> there is no threshold pruning >> >> >> On 17 June 2013 21:14, Per Tunedal <[email protected]> wrote: >> >>> >>> Hi, >>> I can't find any settings for e.g. histogram pruning for the >>> chart-decoder. Is cube pruning the only pruning used by Moses >>> chart-decoder? >>> When using cube pruning with a phrase model I suppose both threshold >>> pruning and histogram pruning are used as well. The cube pruning only >>> affects what new hypothesis to add to the stack, if I've understood the >>> Advanced Features page correctly. >>> Have I missed something? >>> Yours, >>> Per Tunedal >>> _______________________________________________ >>> Moses-support mailing list >>> [email protected] >>> http://mailman.mit.edu/mailman/listinfo/moses-support >>> >> >> >> >> -- >> Hieu Hoang >> Research Associate >> University of Edinburgh >> http://www.hoang.co.uk/hieu > _______________________________________________ > 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
