Implementation details of -write-ngrams?

[Andreas Stolcke]

In message <20061021075440.GA3056 at localhost.localdomain>you wrote:
> Hello,
> 
> Where can I find a detailed description of the algorithm for computing
> n-gram counts (-write-ngrams) in SRILM? Thanks!

The concept of posterior ngram counts is explained in section 3.3.2
of the paper

A. O. Hatch, B. Peskin, and A. Stolcke (2005), Improved Phonetic
Speaker Recognition Using Lattice Decoding, Proc. IEEE ICASSP,
Philadelphia, vol. 1, pp. 169-172.
http://www.speech.sri.com/cgi-bin/run-distill?papers/icassp2005-spkr-phonelats.ps.gz

(where you have to replace "phone" with "word" since the default is to
compute word ngrams).  Note this is not a new concept.

The algorithm is a forward-backward computation with on-the-fly lattice
expansion.  For further details you'll have to read the source code.

Andreas