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On 2/3/2010 9:18 PM, Sun, Xie (MU-Student) wrote:
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<div style=""> Dear Dr.<font size="2">Andreas Stolcke,<br>
<span style="font-family: Tahoma;"><br>
<span style="font-family: Tahoma;">I am PhD student from University
of Missouri. My name is Xie Sun. Right now I am using the SRILM toolkit
to train a language model. I want to use the model adaptation function.
I am using the command as below:<br>
<span style="font-family: Tahoma;"><br>
ngram -lm main_model -adapt-marginals model_adapted -base-marginals
unigram_model -ppl test_file<br>
<span style="font-family: Tahoma;"><br>
<span style="font-family: Tahoma;">where the unigram_model is coming
from the main_model and model_adapted is the mode I want to adapt.<br>
</span></span></span></span></span></font></div>
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I'm assuming model_adapted refers to the marginals of the adaptation
data. Then this command is correct.<br>
Note that -base-marginals needs to be specified only if the unadapted
unigrams are different from the unigrams in main_model.<br>
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<div style=""><font size="2"><span style="font-family: Tahoma;"><span
style="font-family: Tahoma;"><span style="font-family: Tahoma;"><span
style="font-family: Tahoma;"><span style="font-family: Tahoma;"><span
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<span style="font-family: Tahoma;">I am not sure if what I did is
correct. Besides, one more important question is how I can output the
adapted model. I used the option -write-lm. But it does not work. Could
you give me some hints? I will really appreciate your help.<br>
</span></span></span></span></span></span></span></font></div>
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The AdaptMarginals does not support -write-lm at this point. It should
be very slow as you'd have to compute the normalization for every
context appearing in the LM.<br>
You can simulate the effect of -write-lm by employing the
-rescore-ngram option:<br>
<br>
ngram -lm -main_model -adapt-marginals ... -rescore-ngram main_model
write-lm new_model <br>
<br>
Again, this will take a very long time for regular-sized LMs.<br>
<br>
Andreas<br>
<br>
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