Class ScaleDeterministicOnDemandFst takes another DeterministicOnDemandFst and scales the weights (like applying a language-model scale). More...

#include <deterministic-fst.h>

Inheritance diagram for ScaleDeterministicOnDemandFst:

[legend]

Collaboration diagram for ScaleDeterministicOnDemandFst:

[legend]

Public Types
typedef StdArc::Weight	Weight

typedef StdArc::StateId	StateId

typedef StdArc::Label	Label

Public Types inherited from DeterministicOnDemandFst< StdArc >
typedef StdArc ::StateId	StateId

typedef StdArc ::Weight	Weight

typedef StdArc ::Label	Label

Public Member Functions
	ScaleDeterministicOnDemandFst (float scale, DeterministicOnDemandFst< StdArc > *det_fst)

StateId	Start ()

Weight	Final (StateId s)

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

Public Member Functions inherited from DeterministicOnDemandFst< StdArc >
virtual Weight	Final (StateId s)=0

virtual bool	GetArc (StateId s, Label ilabel, StdArc *oarc)=0
	Note: ilabel must not be epsilon. More...

virtual	~DeterministicOnDemandFst ()

Private Attributes
float	scale_

DeterministicOnDemandFst< StdArc > &	det_fst_

Detailed Description

Class ScaleDeterministicOnDemandFst takes another DeterministicOnDemandFst and scales the weights (like applying a language-model scale).

For instance, to subtract existing LM scores from a lattice you could use this with a negative weight; and to interpolate LMs you can also use this with weights less than one.

It's specialized for StdArc because there is no generic way to scale weights.

Definition at line 129 of file deterministic-fst.h.

Member Typedef Documentation

◆ Label

typedef StdArc::Label Label

Definition at line 133 of file deterministic-fst.h.

◆ StateId

typedef StdArc::StateId StateId

Definition at line 132 of file deterministic-fst.h.

◆ Weight

typedef StdArc::Weight Weight

Definition at line 131 of file deterministic-fst.h.

Constructor & Destructor Documentation

◆ ScaleDeterministicOnDemandFst()

ScaleDeterministicOnDemandFst	(	float	scale,
		DeterministicOnDemandFst< StdArc > *	det_fst
	)

inline

Definition at line 136 of file deterministic-fst.h.

137 :

138 scale_(scale), det_fst_(*det_fst) { }

fst::ScaleDeterministicOnDemandFst::det_fst_

DeterministicOnDemandFst< StdArc > & det_fst_

Definition: deterministic-fst.h:160

fst::ScaleDeterministicOnDemandFst::scale_

float scale_

Definition: deterministic-fst.h:159

Member Function Documentation

◆ Final()

Weight Final ( StateId s )

inline

Definition at line 142 of file deterministic-fst.h.

                           {
     // Note: Weight is indirectly a typedef to TropicalWeight.
     Weight final = det_fst_.Final(s);
     if (final == Weight::Zero()) return Weight::Zero();
     else return TropicalWeight(final.Value() * scale_);
   }

◆ GetArc()

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

inline

Definition at line 149 of file deterministic-fst.h.

                                                             {
     if (det_fst_.GetArc(s, ilabel, oarc)) {
       oarc->weight = TropicalWeight(oarc->weight.Value() * scale_);
       return true;
     } else {
       return false;
     }
   }