Re: [Moses-support] decoding a confusion network using Moses' API
Hi all
So, here is the answer. To extract the string from the Hypothesis
object, I used to use just this method:
Hypothesis::GetTargetPhraseStringRep();
for some reason, it seems to work when translating a string but not when
translating a CN or a lattice. I now use the following function
(inspired by what I found in mosesserver.cpp):
string moses_get_hyp(const Hypothesis* hypo) {
string current();
Phrase p = hypo-GetCurrTargetPhrase();
for (size_t pos = 0 ; posp.GetSize() ; pos++) {
const Factor *factor = p.GetFactor(pos, 0);
current += factor-GetString()+string( );
}
const Hypothesis * prev = hypo-GetPrevHypo();
if(prev != NULL)
return moses_get_hyp(prev)+string( )+current;
return current;
}
I must confess that I don't really understand what I'm doing :( I'm just
copying code that works, and, well, that works.
cheers,
Sylvain
On 27/04/12 13:11, Sylvain Raybaud wrote:
Hi Barrow
By adding
cerr [S2TT] GOT TRANSLATION: *hypo endl;
I was able to determine that the translation that are actually generated
look reasonable. The problem therefore lays in how I extract it from the
hypo object. I think I'll be able to find the problem. I'll let the
list know.
thanks for the help!
cheers,
Sylvain
On 26/04/12 17:54, Barry Haddow wrote:
Hi Sylvain
I think ProcessSentence() is the right method to call. If you look at moses
server then you'll see a less cluttered example of how to use the Moses api.
It may be your moses_get_hyp() is not back-tracking through the hypothesis
correctly.
Note that you are calling UntransformScore() which probably explains your
odd
translation score. It doesn't make much sense to do this, as you won't get a
probability (it's not normalised). It is unusual though, that you appear to
have a positive translation score (in log space).
If you increase the verbosity of moses (to 2 or 3) you'll get a better idea
what it is doing, and you can see whether it really is producing of as the
translation, and why.
cheers - Barry
On Thursday 26 April 2012 16:41:06 Sylvain Raybaud wrote:
wild guessing here: in TranslationTask::Run, I see there are many
alternatives for processing the sentence, like doLatticeMBR etc, not
just runing Manager::ProcessSentence()
Maybe one of these alternatives must be run for processing confusion
networks?
cheers
Sylvain
On 26/04/12 15:53, Sylvain Raybaud wrote:
Hi Barrow
Thanks for the tip, that sounds likely indeed. I'll try it again but
last time I ran the software through valgrind, I got so many errors in
external libs that I just gave up.
In the meantime, here is the complete fonction that handles the
decoding, in case someone sees something obviously wrong in here...
static void moses_translate_phonemes(manager_data_t * pool,
translation_pair_t * pair) {
debug(starting);
const TranslationSystem system =
StaticData::Instance().GetTranslationSystem(TranslationSystem::DEFAULT);
/* there is only one translation system for now */
const StaticData staticData = StaticData::Instance();
const vectorFactorType inputFactorOrder =
staticData.GetInputFactorOrder();
MyConfusionNet * cn =
phonemes_to_cn(pool-mp_engine-phonemes_cm,pair-source-phonemes,pool-
mp_config-cn_width,pool-mp_config-cn_thresh,inputFactorOrder);
Manager * manager = new Manager(*cn,staticData.GetSearchAlgorithm(),
system);
manager-ProcessSentence();
const Hypothesis* hypo = manager-GetBestHypothesis();
string hyp = moses_get_hyp(hypo);
char * hyp_ret = (char*)malloc((strlen(hyp.c_str())+1)*sizeof(char));
strcpy(hyp_ret,hyp.c_str());
pair-translation_score = UntransformScore(hypo-GetScore());
translation_pair_set_target(pair, hyp_ret,NULL);
delete manager;
delete cn;
}
cheers,
Sylvain
On 26/04/12 13:49, Barry Haddow wrote:
Hi Sylvain
I'm not familiar with this part of the code, but the strange score
suggests that there's some uninitialised memory. You could try running
through valgrind and it might give some clues,
cheers - Barry
On Thursday 26 Apr 2012 12:24:11 Sylvain Raybaud wrote:
Hi all
I'm using Moses API for decoding a confusion network. The CN is
created from the output of an ASR engine and a confusion matrix. More
precisely (even though it's probably irrelevant to my problem), the ASR
engine provides a string of phonemes (1-best) and the confusion matrix
provides alternatives for each phonemes (the idea was described in
Jiang et al., _Phonetic representation based speech translation_, MT
Summit XIII, 2011).
When the CN is dumped into a file and I use
moses -f moses.phonemes.cn.ini CN
to decode it, everything is fine.
But when I use Moses API (loading the same configuration file), I get
incomplete translations, like:
ASR output (French): nous font sont toujours chimistes plume
rassembleront ch je trouve que le office de ce tout de suite
Re: [Moses-support] decoding a confusion network using Moses' API
wild guessing here: in TranslationTask::Run, I see there are many
alternatives for processing the sentence, like doLatticeMBR etc, not
just runing Manager::ProcessSentence()
Maybe one of these alternatives must be run for processing confusion
networks?
cheers
Sylvain
On 26/04/12 15:53, Sylvain Raybaud wrote:
Hi Barrow
Thanks for the tip, that sounds likely indeed. I'll try it again but
last time I ran the software through valgrind, I got so many errors in
external libs that I just gave up.
In the meantime, here is the complete fonction that handles the
decoding, in case someone sees something obviously wrong in here...
static void moses_translate_phonemes(manager_data_t * pool,
translation_pair_t * pair) {
debug(starting);
const TranslationSystem system =
StaticData::Instance().GetTranslationSystem(TranslationSystem::DEFAULT);
/* there is only one translation system for now */
const StaticData staticData = StaticData::Instance();
const vectorFactorType inputFactorOrder =
staticData.GetInputFactorOrder();
MyConfusionNet * cn =
phonemes_to_cn(pool-mp_engine-phonemes_cm,pair-source-phonemes,pool-mp_config-cn_width,pool-mp_config-cn_thresh,inputFactorOrder);
Manager * manager = new Manager(*cn,staticData.GetSearchAlgorithm(),
system);
manager-ProcessSentence();
const Hypothesis* hypo = manager-GetBestHypothesis();
string hyp = moses_get_hyp(hypo);
char * hyp_ret = (char*)malloc((strlen(hyp.c_str())+1)*sizeof(char));
strcpy(hyp_ret,hyp.c_str());
pair-translation_score = UntransformScore(hypo-GetScore());
translation_pair_set_target(pair, hyp_ret,NULL);
delete manager;
delete cn;
}
cheers,
Sylvain
On 26/04/12 13:49, Barry Haddow wrote:
Hi Sylvain
I'm not familiar with this part of the code, but the strange score suggests
that there's some uninitialised memory. You could try running through
valgrind
and it might give some clues,
cheers - Barry
On Thursday 26 Apr 2012 12:24:11 Sylvain Raybaud wrote:
Hi all
I'm using Moses API for decoding a confusion network. The CN is
created from the output of an ASR engine and a confusion matrix. More
precisely (even though it's probably irrelevant to my problem), the ASR
engine provides a string of phonemes (1-best) and the confusion matrix
provides alternatives for each phonemes (the idea was described in Jiang
et al., _Phonetic representation based speech translation_, MT Summit
XIII, 2011).
When the CN is dumped into a file and I use
moses -f moses.phonemes.cn.ini CN
to decode it, everything is fine.
But when I use Moses API (loading the same configuration file), I get
incomplete translations, like:
ASR output (French): nous font sont toujours chimistes plume
rassembleront ch je trouve que le office de ce tout de suite
Phonetic representation: n u f on s on t t u ge u r ch i m i s t z p l
y m r a s an b l swa r on ch ge swa t r u v k swa l swa oh f i s swa d
swa s swa t u d s h i t
Translation: of
score: 903011968.00
Note that the transcription is poor (I haven't really tuned the ASR
engine), but still, the translation ought to be more than just of.
Sometimes it's several words, I guess it's a phrase in the phrase table.
The word generally seems to be the translation of a word in the source
sentence.
When I use moses on command line to translate either the 1-best or the
the CN, I get a reasonable translation. When I use the API to translate
the 1-best phonetic representation, I also get a reasonable translation.
I think the CN object is created correctly because moses loads it and
prints it prior to decoding (this is normal verbose behavior). I also
tried to create a PCN object, and got exactly the same results. So I
guess the problem is either how I tell moses to decode it or how I
extract the result from the Hypothesis object. But I'm clueless about
what's the problem is here, since the code is working when I just
translate a string. The translation score seems ridiculously high too.
I'll give below the corresponding code.
Decoding and hypothesis extraction:
***
[...]
Manager * manager = new Manager(*cn,staticData.GetSearchAlgorithm(),
system);
manager-ProcessSentence();
const Hypothesis* hypo = manager-GetBestHypothesis();
string hyp = moses_get_hyp(hypo);
[...]
pair-translation_score = UntransformScore(hypo-GetScore());
[...]
string moses_get_hyp(const Hypothesis* hypo) {
return hypo-GetTargetPhraseStringRep();
}
Creation of the CN:
***
/** new class derived from ConfusionNet, with a new method for directly
creating CN */
class MyConfusionNet : public ConfusionNet {
public:
void addCol(Column);
};
void MyConfusionNet::addCol(Column col) {
data.push_back(col);
}
/** create a column of the CN */
static MyConfusionNet::Column create_phoneme_col(confusion_matrix_t *
cm, const char * ph, int
