Defines a LogWriter that can perform lossy decimation on a stream of DataEntries, by outputting values that can be reconstructed via linear interpolation. More...

#include <LinearApproxLogWriter.h>

Inheritance diagram for LinearApproxLogWriter:

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Collaboration diagram for LinearApproxLogWriter:

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Classes
class	VarData

Public Member Functions
	LinearApproxLogWriter (LogWriter &outputTo, const Str &varName, DataValue *approxErrorValue, bool makeDirEntries, Logger &logger)

virtual	~LinearApproxLogWriter ()

virtual unsigned int	write (const LogEntry entry, const Unit unit=NULL)
	Write an entry to the text log. More...

virtual unsigned int	writeHeader ()
	Write the log header, if any. More...

virtual void	endCycle ()
	Do what needs to be done at the end of the cycle. More...

virtual void	config (Logger &logger)
	Configure from a config file. More...

virtual unsigned int	writeFooter ()
	Write the log footer, if any. More...

virtual void	setParameter (DataValue *approxError, Logger &logger)

virtual unsigned int	flush ()

Public Member Functions inherited from DecimationLogWriter
	DecimationLogWriter (LogWriter &outputTo, DecimationType decimationType)
	Constructor. More...

virtual	~DecimationLogWriter ()
	Destructor. More...

DecimationType	getDecimationType () const

Public Member Functions inherited from LogWriter
virtual	~LogWriter ()
	Destructor. More...

virtual void	setOutStream (OutStream &outStream)
	Sets the OutStream. More...

virtual bool	isValid ()
	Return true if logStream_ is available. More...

virtual void	resetInputs ()
	Reset cached input settings. More...

void	addParent ()

void	removeParent ()

int	getParentCount ()

virtual void	activate ()

virtual void	deactivate ()

virtual bool	isActive ()

virtual void	lockWrites ()

virtual void	unlockWrites ()

Private Member Functions
	LinearApproxLogWriter (const LinearApproxLogWriter &old)

unsigned int	sendOutput (DataEntry *dataEntry)

Private Attributes
const Str	varName_

DataValue *	approxErrorValue_

LinearApproxLogWriter::VarData *	varData_

EventEntry	cycleStartEntry_

Timestamp	lastTime_

Friends
class	Supervisor

Additional Inherited Members
Public Types inherited from DecimationLogWriter
enum	DecimationType { UNDEFINED_DECIMATION = -1, NO_DECIMATION, ALL_DATA, LINEAR_APPROXIMATION, MOST_RECENT, DECIMATION_COUNT, DECIMATION_MULTI }

Public Types inherited from LogWriter
enum	ServiceType { NO_SERVICE = -1, SERVICE_COURIER, SERVICE_EXPRESS, SERVICE_PRIORITY, SERVICE_NORMAL, SERVICE_BULK, SERVICE_COUNT, SERVICE_MULTI }

Static Public Member Functions inherited from DecimationLogWriter
static const char *	DecimationType2Str (DecimationLogWriter::DecimationType decimationType)

static DecimationType	Str2DecimationType (const char *const typeStr, int len=-1)

Static Public Member Functions inherited from LogWriter
static ServiceType	Str2ServiceType (const char *const serviceTypeStr, int len=-1)

static const char *	ServiceType2Str (LogWriter::ServiceType serviceType)

static size_t	ServiceType2Strlen (LogWriter::ServiceType serviceType)

Static Public Attributes inherited from DecimationLogWriter
static const char *const	DECIMATION_TYPE_STRS [DECIMATION_COUNT]

static const size_t	DECIMATION_TYPE_STRLEN [DECIMATION_COUNT]

Static Public Attributes inherited from LogWriter
static const char *const	SERVICE_TYPE_STRS [SERVICE_COUNT]

static size_t const	SERVICE_TYPE_STRLEN [SERVICE_COUNT]

Protected Member Functions inherited from LogWriter
	LogWriter ()
	Protected constructor for pure virtual class. More...

	LogWriter (OutStream &outStream)
	Protected constructor for pure virtual class. More...

Protected Attributes inherited from DecimationLogWriter
LogWriter &	outputTo_
	Stores an LogWriter. More...

DecimationType	decimationType_
	Stores the decimationType. More...

Protected Attributes inherited from LogWriter
OutStream *	logStream_
	Stores an OutStream. More...

bool	wroteHeader_

bool	wroteFooter_

Mutex	writeMutex_

int	parentCount_

bool	active_

Detailed Description

Defines a LogWriter that can perform lossy decimation on a stream of DataEntries, by outputting values that can be reconstructed via linear interpolation.

The resulting output will have no more error than the specified error limits (using the DataValue's absDiff() function to calculate differences – important in the case of Location values). See:
K. Konstantinides and B. K. Natarajan, "An architecture for lossy compression of waveforms using piecewise linear approximation," IEEE Trans. Signal Processing, vol. 42, no. 9, pp. 2449-2454, Sept. 1994. (http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=317866)

See TextLogWriter for conversion to text See FileLogWriter for output to the filesystem.

Constructor & Destructor Documentation

LinearApproxLogWriter::LinearApproxLogWriter	(	LogWriter &	outputTo,
		const Str &	varName,
		DataValue *	approxErrorValue,
		bool	makeDirEntries,
		Logger &	logger
	)