Using GIZA++

If you have parallel corpora you can use GIZA++ to make bilingual dictionaries.

Download your corpora, and convert into one sentence per line.

Download and compile GIZA++.

Use plain2snt.out to convert your corpus into GIZA++ format:

$ plain2snt.out sv-text.txt da-text.txt 
w1:sv-text w2:da-text
sv-text -> sv-text
da-text -> da-text

You may get some warnings about empty sentences like these:

WARNING: filtered out empty sentence (source: sv-text.txt 23 target: da-text.txt 0).
WARNING: filtered out empty sentence (source: sv-text.txt 34 target: da-text.txt 0).

if it is a large corpus you may get a lot of warnings... — if you have a lot of warnings, consider changing the corpus.

After you've done this, you should have a couple of .snt files and a couple of .vcb files.

Next you need to generate word classes, using mkcls:

$ mkcls -m2 -psv-text.txt -c50 -Vsv-text.vcb.classes opt >& mkcls1.log
$ mkcls -m2 -pda-text.txt -c50 -Vda-text.vcb.classes opt >& mkcls1.log

Now use GIZA++ to build your dictionary (-S is the source language, -T is the target language, -C is the generated aligned text file, and -o is the output file prefix):

$ GIZA++ -S sv-text.vcb -T da-text.vcb -C sv-text_da-text.snt -p0 0.98 -o dictionary >& dictionary.log

and wait... You can watch the log in dictionary.log... but the training is likely to take upwards of 10 hours (at most several days), so have something else planned.

See also

• Corpora

External links

• Moses Language Model Howto v2
• statmt.org: Factored training