Octane v1.01.20 - The Open Compression Toolkit for C++

http://octane.sourceforge.net/

SymbolWeightVector Class Reference

#include <symbolweightvector.hpp>

Inheritance diagram for SymbolWeightVector:

List of all members.

---

Detailed Description

The SymbolWeightVector class is a helper class which holds a vector of probabilities, typically associated with a modeler.

It provides basic functionality to save and load state and display debugging information, and report memory usage.

Definition at line 61 of file symbolweightvector.hpp.

Public Member Functions
	SymbolWeightVector ()
	constructor
virtual	~SymbolWeightVector ()
	destructor
virtual std::string	GetName ()
	provide a unique name for the coder, used in some cases to automatically register the object with a manager
virtual std::string	GetDescription ()
	optionally provide a longer (maybe 20-60 characters) description
virtual std::string	GetHelpInformation ()
	optionally provide more information about the object on request for help
virtual void	ShowDebuggingInfo ()
	show any debugging info on request (used by various derived classes) [optional]
virtual unsigned int	GetMemoryUsed ()
	Report actual current memory usage (in bytes).
virtual unsigned int	GetDiskspaceUsed (bool fortempdecompressiononly)
	Report disk space (in bytes) that would be used when saving state to file (in bytes).
virtual bool	SaveState (bitwriter &to, bool fortempdecompressiononly)
	Save state of object to output stream (if appropriate).
virtual bool	LoadState (bitreader &from)
	Load state of object from input stream (if appropriate).
void	ResetWeights ()
	Reset all probabilities.
void	NormalizeToProbabilityDistribution ()
	Normalize vector values into a probability distribution.
void	SetSymbolCount (int newsize)
	Set the number of symbols we should store weights for; can be called at any time to shrink or grow size.
int	GetSymbolCount ()
	Get count of symbols.
TSymbolWeightVectorWeight	GetSymbolWeight (int index)
	Get the weight (probability or freq count) of a symbol.
void	SetSymbolWeight (int index, TSymbolWeightVectorWeight weight)
	Set the weight (probability or freq count) of a symbol.
void	IncremementSymbolWeight (int index)
	Increment the weight of a given entry.
bool	CountSymbolFrequencies (OctaneParser *parserp, bitreader &from)
	Higher level function for automatic setting of frequencies with help of parser.
void	EnforceZeroCountFloor (TSymbolWeightVectorWeight symbolfloorval)
	It's common that we may have symbols for characters we dont see for completeness and it's common to want to force these to some minimal value (like 1); some coders (like huffman), will break without this.
Protected Attributes
int	symbolcount
	size of vector (# of symbol probabilities)
vector< TSymbolWeightVectorWeight >	weightvector
	vector of probabilities

---

Member Function Documentation

virtual std::string SymbolWeightVector::GetName (   )  [inline, virtual]

provide a unique name for the coder, used in some cases to automatically register the object with a manager Returns: a short *unique* name Reimplemented from OctaneClass. Definition at line 76 of file symbolweightvector.hpp. {return "SymbolWeightVector";}

virtual std::string SymbolWeightVector::GetDescription (   )  [inline, virtual]

optionally provide a longer (maybe 20-60 characters) description Returns: a one line description Reimplemented from OctaneClass. Definition at line 77 of file symbolweightvector.hpp. {return "Symbol Weight Vector";}

virtual std::string SymbolWeightVector::GetHelpInformation (   )  [inline, virtual]

optionally provide more information about the object on request for help Returns: a long string (can be multiple newlines) Reimplemented from OctaneClass. Definition at line 78 of file symbolweightvector.hpp. {return "";}

bool SymbolWeightVector::SaveState (  bitwriter &  to, bool  fortempdecompressiononly )  [virtual]

Save state of object to output stream (if appropriate). Returns: true on success (or if no information needs to be saved). Reimplemented from OctaneClass. Definition at line 58 of file symbolweightvector.cpp. References bitwriter::put(), symbolcount, and weightvector. Referenced by OctaneModeler_WeightVectored::SaveState(). { // save state // return true on success to.put(symbolcount); for (int count=0;count<symbolcount;++count) to.put(weightvector[count]); return true; }

bool SymbolWeightVector::LoadState (  bitreader &  from  )  [virtual]

Load state of object from input stream (if appropriate). Returns: true on success (or if no information needs to be loaded). Reimplemented from OctaneClass. Definition at line 68 of file symbolweightvector.cpp. References bitreader::get(), SetSymbolCount(), symbolcount, and weightvector. Referenced by OctaneModeler_WeightVectored::LoadState(). { // load state from.get(symbolcount); // force size of vector SetSymbolCount(symbolcount); // read weights for (int count=0;count<symbolcount;++count) from.get(weightvector[count]); // return true on success return true; }

bool SymbolWeightVector::CountSymbolFrequencies (  OctaneParser *  parserp, bitreader &  from )

Higher level function for automatic setting of frequencies with help of parser. This will actually parse the input using the parser, and count frequency of each symbol, and then normalize it into a probability distribution. Returns: true on success Definition at line 116 of file symbolweightvector.cpp. References OctaneParser::GetSymbolCount(), IncremementSymbolWeight(), OctaneParser::ParseNextSymbolFromInput(), ResetWeights(), and SetSymbolCount(). Referenced by ZeroOrderModeler::CreateModelUsingStream(). { // higher level function for automatic setting of frequencies with help of parser; returns true on success bool bretv=true; int symbolnumber; // set our weight vector to size of symbolcount SetSymbolCount(parserp->GetSymbolCount()); // reset probabilities ResetWeights(); // now parse input and count frequencies, OOP parsing a symbol from parser until we hit end while (parserp->ParseNextSymbolFromInput(from,symbolnumber)) IncremementSymbolWeight(symbolnumber); // return success return bretv; }

---

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

• modelers/symbolweightvector.hpp
• modelers/symbolweightvector.cpp

 

Generated on 20 May 2004 by doxygen 1.3.3