RnnlmDeterministicFst Class Reference

#include <kaldi-rnnlm.h>

Inheritance diagram for RnnlmDeterministicFst:

Collaboration diagram for RnnlmDeterministicFst:

Public Types
typedef fst::StdArc::Weight	Weight
typedef fst::StdArc::StateId	StateId
typedef fst::StdArc::Label	Label
Public Types inherited from DeterministicOnDemandFst< fst::StdArc >
typedef fst::StdArc ::StateId	StateId
typedef fst::StdArc ::Weight	Weight
typedef fst::StdArc ::Label	Label

Public Member Functions
	RnnlmDeterministicFst (int32 max_ngram_order, KaldiRnnlmWrapper *rnnlm)
virtual StateId	Start ()
virtual Weight	Final (StateId s)
virtual bool	GetArc (StateId s, Label ilabel, fst::StdArc *oarc)
Public Member Functions inherited from DeterministicOnDemandFst< fst::StdArc >
virtual Weight	Final (StateId s)=0
virtual bool	GetArc (StateId s, Label ilabel, fst::StdArc *oarc)=0
	Note: ilabel must not be epsilon. More...
virtual	~DeterministicOnDemandFst ()

Private Types
typedef unordered_map< std::vector< Label >, StateId, VectorHasher< Label > >	MapType

Private Attributes
StateId	start_state_
MapType	wseq_to_state_
std::vector< std::vector< Label > >	state_to_wseq_
KaldiRnnlmWrapper *	rnnlm_
int32	max_ngram_order_
std::vector< std::vector< float > >	state_to_context_

Detailed Description

Definition at line 70 of file kaldi-rnnlm.h.

Member Typedef Documentation

Label

typedef fst::StdArc::Label Label

Definition at line 75 of file kaldi-rnnlm.h.

MapType

typedef unordered_map<std::vector<Label>, StateId, VectorHasher<Label> > MapType

private

Definition at line 92 of file kaldi-rnnlm.h.

StateId

typedef fst::StdArc::StateId StateId

Definition at line 74 of file kaldi-rnnlm.h.

Weight

typedef fst::StdArc::Weight Weight

Definition at line 73 of file kaldi-rnnlm.h.

Constructor & Destructor Documentation

RnnlmDeterministicFst()

RnnlmDeterministicFst	(	int32	max_ngram_order,
		KaldiRnnlmWrapper *	rnnlm
	)

Definition at line 74 of file kaldi-rnnlm.cc.

References KaldiRnnlmWrapper::GetHiddenLayerSize(), KALDI_ASSERT, and KaldiRnnlmWrapper::rnnlm_.

                                                                       {
  KALDI_ASSERT(rnnlm != NULL);
  max_ngram_order_ = max_ngram_order;
  rnnlm_ = rnnlm;

  // Uses empty history for <s>.
  std::vector<Label> bos;
  std::vector<float> bos_context(rnnlm->GetHiddenLayerSize(), 1.0);
  state_to_wseq_.push_back(bos);
  state_to_context_.push_back(bos_context);
  wseq_to_state_[bos] = 0;
  start_state_ = 0;
}

Member Function Documentation

Final()

fst::StdArc::Weight Final ( StateId  s )

virtual

Definition at line 89 of file kaldi-rnnlm.cc.

References KALDI_ASSERT, logprob, and KaldiRnnlmWrapper::rnnlm_.

                                                      {
  // At this point, we should have created the state.
  KALDI_ASSERT(static_cast<size_t>(s) < state_to_wseq_.size());

  std::vector<Label> wseq = state_to_wseq_[s];
  BaseFloat logprob = rnnlm_->GetLogProb(rnnlm_->GetEos(), wseq,
                                         state_to_context_[s], NULL);
  return Weight(-logprob);
}

GetArc()

bool GetArc ( StateId  s, Label  ilabel, fst::StdArc *  oarc  )

virtual

Definition at line 99 of file kaldi-rnnlm.cc.

References KALDI_ASSERT, logprob, and KaldiRnnlmWrapper::rnnlm_.

                                                                           {
  // At this point, we should have created the state.
  KALDI_ASSERT(static_cast<size_t>(s) < state_to_wseq_.size());

  std::vector<Label> wseq = state_to_wseq_[s];
  std::vector<float> new_context(rnnlm_->GetHiddenLayerSize());
  BaseFloat logprob = rnnlm_->GetLogProb(ilabel, wseq,
                                         state_to_context_[s], &new_context);

  wseq.push_back(ilabel);
  if (max_ngram_order_ > 0) {
    while (wseq.size() >= max_ngram_order_) {
      // History state has at most <max_ngram_order_> - 1 words in the state.
      wseq.erase(wseq.begin(), wseq.begin() + 1);
    }
  }

  std::pair<const std::vector<Label>, StateId> wseq_state_pair(
      wseq, static_cast<Label>(state_to_wseq_.size()));

  // Attemps to insert the current <lseq_state_pair>. If the pair already exists
  // then it returns false.
  typedef MapType::iterator IterType;
  std::pair<IterType, bool> result = wseq_to_state_.insert(wseq_state_pair);

  // If the pair was just inserted, then also add it to <state_to_wseq_> and
  // <state_to_context_>.
  if (result.second == true) {
    state_to_wseq_.push_back(wseq);
    state_to_context_.push_back(new_context);
  }

  // Creates the arc.
  oarc->ilabel = ilabel;
  oarc->olabel = ilabel;
  oarc->nextstate = result.first->second;
  oarc->weight = Weight(-logprob);

  return true;
}

Start()

virtual StateId Start ( )

inlinevirtual

Implements DeterministicOnDemandFst< fst::StdArc >.

Definition at line 82 of file kaldi-rnnlm.h.

{ return start_state_; }

Member Data Documentation

max_ngram_order_

int32 max_ngram_order_

private

Definition at line 98 of file kaldi-rnnlm.h.

rnnlm_

KaldiRnnlmWrapper* rnnlm_

private

Definition at line 97 of file kaldi-rnnlm.h.

start_state_

StateId start_state_

private

Definition at line 93 of file kaldi-rnnlm.h.

state_to_context_

std::vector<std::vector<float> > state_to_context_

private

Definition at line 99 of file kaldi-rnnlm.h.

state_to_wseq_

std::vector<std::vector<Label> > state_to_wseq_

private

Definition at line 95 of file kaldi-rnnlm.h.

wseq_to_state_

MapType wseq_to_state_

private

Definition at line 94 of file kaldi-rnnlm.h.

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The documentation for this class was generated from the following files:

• lm/kaldi-rnnlm.h
• lm/kaldi-rnnlm.cc