[SRILM User List] harmonizing results with/without '-use-server'

Andrew Philpot philpot at isi.edu
Mon Apr 18 14:31:33 PDT 2011


Testing on a rather small language model, I notice that I get
different results for a given input lattice/pfsg depending on whether
I interrogate the LM directly on the command line or resident in a
server.

Precisely, the server is started thus:

   ngram -lm data/lm5a.lm -unk -server-port 2525

and then invoked via a command such as

   lattice-tool -in-lattice simple.pfsg -use-server 2525 at cent64.isi.edu 
-nbest-decode 10 -out-nbest-dir server-out/

while the command line version is invoked thus:

   lattice-tool -unk -in-lattice simple.pfsg -lm data/lm5a.lm 
-nbest-decode 10 -out-nbest-dir cmdline-out/

It's my intention and understanding that these two would be
equivalent, but they are not.  As far as I can tell, the nature of the
discrepancy is that the server generates only acoustic probabilities,
no LM probabilities (well, they are all 0).  Also the order of
returned results is different, but that very well could be due to the
former issue.  Finally, the acoustic probabilities are are equal
(within a 10-best window) in the server-based case, but vary slightly
in the command line-based case.

I'd like to have results equivalent to the command-line invocation,
but with the potential speedup provided by the
-server-port/-use-server case.  Is this possible, and if so, which
parameter adjustments do I need to make?

Andrew



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