GExtremaFinder Class Reference

#include <GExtremaFinder.hh>

Public Member Functions
Constructors, destructors, affectation
	GExtremaFinder (u_int n=0, double *data=NULL, double bin=1.)
	GExtremaFinder (GRealSampleFFT *sptr)
	GExtremaFinder (GRealSampleFFT &s)
	GExtremaFinder (const GExtremaFinder &original)
GExtremaFinder &	operator= (const GExtremaFinder &original)
virtual	~GExtremaFinder ()
Access to data
bool	IsSampleLocal () const
const GRealSampleFFT *	GetSample () const
GRealSampleFFT *	GetSample ()
const GRealSampleFFT *	GetDerivativeSample () const
GRealSampleFFT *	GetDerivativeSample ()
u_int	GetExtremaNum () const
const double *	GetExtremaValues () const
double *	GetExtremaValues ()
const double *	GetExtremaPositions () const
double *	GetExtremaPositions ()
const u_int *	GetExtremaBins () const
u_int *	GetExtremaBins ()
const bool *	GetExtremaMax () const
bool *	GetExtremaMax ()
u_int	GetMaximaNum () const
const double *	GetMaximaValues () const
double *	GetMaximaValues ()
const double *	GetMaximaPositions () const
double *	GetMaximaPositions ()
const u_int *	GetMaximaBins () const
u_int *	GetMaximaBins ()
const double *	GetMaximaCenters () const
double *	GetMaximaCenters ()
const double *	GetMaximaAmplitudes () const
double *	GetMaximaAmplitudes ()
const double *	GetMaximaAverages () const
double *	GetMaximaAverages ()
double	GetMaxValue (u_int i) const
double	GetMaxPosition (u_int i) const
u_int	GetMaxBin (u_int i) const
double	GetMaxCenter (u_int i) const
double	GetMaxAmplitude (u_int i) const
double	GetMaxAverage (u_int i) const
u_int	GetMaxPrevMinBin (u_int i) const
u_int	GetMaxNextMinBin (u_int i) const
double	GetMaxPrevMinPos (u_int i) const
double	GetMaxNextMinPos (u_int i) const
double	GetMaxPrevMinVal (u_int i) const
double	GetMaxNextMinVal (u_int i) const
Extrema analysis
virtual int	Analyse ()
virtual int	Analyse (GRealSampleFFT *sptr)
virtual int	Analyse (GRealSampleFFT &s)
virtual int	DifferentialThreshold (double thr)
virtual void	SetMaximaLowThreshold (double thr)
virtual void	UnsetMaximaLowThreshold ()
virtual int	AnalyseMaxima ()
virtual int	AnalyseMaxima (GRealSampleFFT &s)
virtual int	AnalyseMaxima (GRealSampleFFT &s, double low_thr)
virtual int	AnalyseMaxima (GRealSampleFFT &s, double low_thr, double dif_thr)

Protected Attributes
GRealSampleFFT *	sample_ptr
	Pointer to the data sample to analyse.
bool	sample_local
	Whether the sample is allocated by the class.
GRealSampleFFT *	deriv_ptr
	Derivative of the data sample.
bool	analyzed
	Whether the extrema have been analyzed.
u_int	alloc_size
	Allocated size for arrays.
u_int	extr_num
	Number of extrema.
double *	extr_val
	Array of extrema values.
double *	extr_pos
	Array of extrema positions.
u_int *	extr_bin
	Array of bins with extrema.
bool *	extr_max
	Array indicating if extrema are maxima (or minima)
bool	max_thr_use
	Use of a low signal threshold for maxima analysis.
double	max_thr_low
	Low signal threshold for maxima analysis.
u_int	max_num
	Number of maxima.
double *	max_val
	Array of maxima values.
double *	max_pos
	Array of maxima positions.
u_int *	max_bin
	Array of bins with maxima.
double *	max_ctr
	Array of maxima zone average positions.
double *	max_amp
	Array of maxima zone sum amplitude.
double *	max_avg
	Array of maxima zone average amplitude.
double *	max_prev_min_val
	Array of values of the minimum before maxima.
double *	max_next_min_val
	Array of values of the minimum after maxima.
double *	max_prev_min_pos
	Array of positions of the minimum before maxima.
double *	max_next_min_pos
	Array of positions of the minimum after maxima.
u_int *	max_prev_min_bin
	Array of positions of the minimum before maxima.
u_int *	max_next_min_bin
	Array of positions of the minimum after maxima.

Private Member Functions
	GObjectV (GExtremaFinder)

Initialisation and setting functions
virtual int	InitData (u_int n, double *data, double bin=1.)
virtual int	InitData (GRealSampleFFT *sptr)
virtual int	InitData (GRealSampleFFT &s)
virtual void	ResetData ()
virtual void	ClearData ()
virtual void	CopyData (const GExtremaFinder &original)

Detailed Description

This class performs a maxima / minima search on a sample of real data.

Extrema analysis

Maxima analysis

The maxima analysis is performed from the results of the extrema analysis (maxima and minima).

The analysis selects the maxima and sets the corresponding information in dedicated arrays. The information is the following:

• the number of maxima;
• the raw data from maxima analysis:
  • Values: the signal amplitude at maxima positions;
  • Positions: the position of the maxima along signal axis;
  • Bins: the sample bins that contain a maximum;
• a more detailed analysis of the maxima, analysing the signal over the full range from the preceeding to the following minimum:
  • Centers: total signal mean position for the maxima;
  • Amplitudes: integrated signal for the maxima;
  • Averages: average signal for the maxima;
  • the information about the maxima analysis zone: position and signal of the lower and upper limits of the zone asociated to the maxima.

For the maxima analysis, it is also possible to set a low signal threshold below which the data are not considered:

• a maximum below this threshold is ignored;
• the local maxima zone for integration / average is limited to a region where the signal does not drop below this threshold.

Constructor & Destructor Documentation

GExtremaFinder::GExtremaFinder	(	u_int	n = 0,
		double *	data = NULL,
		double	bin = 1.
	)

Base constructor. The data array is copied into an internal sample for the analysis.

Parameters

n	array dimension (should be a power of 2)
data	data array
bin	bin size

References alloc_size, analyzed, deriv_ptr, extr_bin, extr_max, extr_num, extr_pos, extr_val, InitData(), max_amp, max_avg, max_bin, max_ctr, max_next_min_bin, max_next_min_pos, max_next_min_val, max_num, max_pos, max_prev_min_bin, max_prev_min_pos, max_prev_min_val, max_thr_low, max_thr_use, max_val, sample_local, and sample_ptr.

GExtremaFinder::GExtremaFinder

(

GRealSampleFFT *

sptr

)

Constructor from a GRealSampleFFT pointer. The GRealSampleFFT object is adopted (deleted with the GExtremaFinder object).

Parameters

sptr	pointer to the sample

References alloc_size, analyzed, deriv_ptr, extr_bin, extr_max, extr_num, extr_pos, extr_val, InitData(), max_amp, max_avg, max_bin, max_ctr, max_next_min_bin, max_next_min_pos, max_next_min_val, max_num, max_pos, max_prev_min_bin, max_prev_min_pos, max_prev_min_val, max_thr_low, max_thr_use, max_val, sample_local, and sample_ptr.

GExtremaFinder::GExtremaFinder

(

GRealSampleFFT &

s

)

Constructor from a GRealSampleFFT object. The GRealSampleFFT object is external.

Parameters

s	sample object

References alloc_size, analyzed, deriv_ptr, extr_bin, extr_max, extr_num, extr_pos, extr_val, InitData(), max_amp, max_avg, max_bin, max_ctr, max_next_min_bin, max_next_min_pos, max_next_min_val, max_num, max_pos, max_prev_min_bin, max_prev_min_pos, max_prev_min_val, max_thr_low, max_thr_use, max_val, sample_local, and sample_ptr.

GExtremaFinder::GExtremaFinder

(

const GExtremaFinder &

original

)

Copy constructor.

Parameters

original

object to be copied

References alloc_size, analyzed, CopyData(), deriv_ptr, extr_bin, extr_max, extr_num, extr_pos, extr_val, max_amp, max_avg, max_bin, max_ctr, max_next_min_bin, max_next_min_pos, max_next_min_val, max_num, max_pos, max_prev_min_bin, max_prev_min_pos, max_prev_min_val, max_thr_low, max_thr_use, max_val, sample_local, and sample_ptr.

GExtremaFinder::~GExtremaFinder ( )

virtual

Destructor: cleans-up the data.

References ResetData().

Member Function Documentation

int GExtremaFinder::Analyse ( )

virtual

Function that performs the extrema analysis for the sample currently defined. The function returns the number of extrema points, or a negative value in case of error.

References analyzed, ClearData(), deriv_ptr, GRealSampleFFT::Derivate(), extr_bin, extr_max, extr_num, extr_pos, extr_val, GBaseSampleFFT::GetFunctionData(), GBaseSampleFFT::GetSamplesNumber(), GBaseSampleFFT::GetTimeStep(), GLogWarning(), and sample_ptr.

Referenced by Analyse(), and AnalyseMaxima().

int GExtremaFinder::Analyse ( GRealSampleFFT *  sptr )

virtual

Function that sets a new sample (locally) and performs the extrema analysis.

Parameters

sptr	pointer to the sample

References Analyse(), and InitData().

int GExtremaFinder::Analyse ( GRealSampleFFT &  s )

virtual

Function that sets a new sample (externally) and performs the extrema analysis.

Parameters

s	sample object

References Analyse(), and InitData().

int GExtremaFinder::AnalyseMaxima ( )

virtual

Function that computes the integral and average signal for each maximum. The extrema must have been analysed previously. For each maximum, the analysis is performed between previous and next minimum. The function returns the number of maxima, or a negative value in case of error.

References analyzed, extr_bin, extr_max, extr_num, extr_pos, extr_val, GBaseSampleFFT::GetFunctionData(), GBaseSampleFFT::GetSamplesNumber(), GBaseSampleFFT::GetTimeStep(), GLogWarning(), max_amp, max_avg, max_bin, max_ctr, max_next_min_bin, max_next_min_pos, max_next_min_val, max_num, max_pos, max_prev_min_bin, max_prev_min_pos, max_prev_min_val, max_thr_low, max_thr_use, max_val, and sample_ptr.

Referenced by AnalyseMaxima().

int GExtremaFinder::AnalyseMaxima ( GRealSampleFFT &  s )

virtual

Function that analyses the argument sample and computes the data for maxima (see GExtremaFinder::Analyse and GExtremaFinder::AnalyseMaxima functions).

Parameters

s	sample object

References Analyse(), and AnalyseMaxima().

int GExtremaFinder::AnalyseMaxima ( GRealSampleFFT &  s, double  low_thr  )

virtual

Function that analyses the argument sample and computes the data for maxima (see GExtremaFinder::Analyse and GExtremaFinder::AnalyseMaxima functions). The maxima analysis is performed with a low signal threshold value. If a low threshold is defined the GExtremaFinder::DifferentialThreshold is called.

Parameters

s	sample object
low_thr	maxima analysis low threshold

References Analyse(), AnalyseMaxima(), and SetMaximaLowThreshold().

int GExtremaFinder::AnalyseMaxima ( GRealSampleFFT &  s, double  low_thr, double  dif_thr  )

virtual

Function that analyses the argument sample and computes the data for maxima (see GExtremaFinder::Analyse and GExtremaFinder::AnalyseMaxima functions). The maxima analysis is performed with a low signal threshold value. If an extrema difference validation threshold is defined the GExtremaFinder::DifferentialThreshold is called.

Parameters

s	sample object
low_thr	maxima analysis low threshold
dif_thr	extrema validation threshold

References Analyse(), AnalyseMaxima(), DifferentialThreshold(), and SetMaximaLowThreshold().

void GExtremaFinder::ClearData ( )

virtual

Fonctions that clears the analysis.

References analyzed, extr_num, and max_num.

Referenced by Analyse(), and InitData().

void GExtremaFinder::CopyData ( const GExtremaFinder &  original )

protectedvirtual

This function copies the data from original to the current object.

Parameters

original

object to be copied

References analyzed, deriv_ptr, extr_bin, extr_max, extr_pos, extr_val, GetExtremaBins(), GetExtremaMax(), GetExtremaNum(), GetExtremaPositions(), GetExtremaValues(), GetMaximaAmplitudes(), GetMaximaAverages(), GetMaximaBins(), GetMaximaCenters(), GetMaximaNum(), GetMaximaPositions(), GetMaximaValues(), InitData(), IsSampleLocal(), max_amp, max_avg, max_bin, max_ctr, max_next_min_bin, max_next_min_pos, max_next_min_val, max_pos, max_prev_min_bin, max_prev_min_pos, max_prev_min_val, max_thr_low, max_thr_use, max_val, and sample_ptr.

Referenced by GExtremaFinder(), and operator=().

int GExtremaFinder::DifferentialThreshold ( double  thr )

virtual

Function that selects the extrema if the amplitude difference is larger than the argument threshold. The extrema must have been analysed previously. If the threshold is smaller than a previously set threshold for the same sample, nothing is done. The function returns the new number of extrema, or a negative value in case of error.

Parameters

thr	selected threshold

cerr << "First local extremum " << extr_bin[ix] << " (#" << ix << "): " << extr_val[ix] << endl;

References analyzed, extr_bin, extr_max, extr_num, extr_pos, extr_val, GBaseSampleFFT::GetTimeStep(), GLogWarning(), and sample_ptr.

Referenced by AnalyseMaxima().

const GRealSampleFFT * GExtremaFinder::GetDerivativeSample ( ) const

inline

Return the derivative sample.

References deriv_ptr.

GRealSampleFFT * GExtremaFinder::GetDerivativeSample ( )

inline

Return the derivative sample.

References deriv_ptr.

const u_int * GExtremaFinder::GetExtremaBins ( ) const

inline

Returns the array of extrema sample bin indexes.

References extr_bin.

Referenced by CopyData().

u_int * GExtremaFinder::GetExtremaBins ( )

inline

Returns the array of extrema sample bin indexes.

References extr_bin.

const bool * GExtremaFinder::GetExtremaMax ( ) const

inline

Returns the array of maxima flags.

References extr_max.

Referenced by CopyData().

bool * GExtremaFinder::GetExtremaMax ( )

inline

Returns the array of maxima flags.

References extr_max.

u_int GExtremaFinder::GetExtremaNum ( ) const

inline

Returns the number of extrema.

References extr_num.

Referenced by CopyData().

const double * GExtremaFinder::GetExtremaPositions ( ) const

inline

Returns the array of extrema positions.

References extr_pos.

Referenced by CopyData().

double * GExtremaFinder::GetExtremaPositions ( )

inline

Returns the array of extrema positions.

References extr_pos.

const double * GExtremaFinder::GetExtremaValues ( ) const

inline

Returns the array of extrema values.

References extr_val.

Referenced by CopyData().

double * GExtremaFinder::GetExtremaValues ( )

inline

Returns the array of extrema values.

References extr_val.

double GExtremaFinder::GetMaxAmplitude ( u_int  i ) const

inline

Return the integral signal for a maximum.

Parameters

i	maximum index

References max_amp.

double GExtremaFinder::GetMaxAverage ( u_int  i ) const

inline

Return the average signal for a maximum.

Parameters

i	maximum index

References max_avg.

u_int GExtremaFinder::GetMaxBin ( u_int  i ) const

inline

Return the sample bin index for a maximum.

Parameters

i	maximum index

References max_bin.

double GExtremaFinder::GetMaxCenter ( u_int  i ) const

inline

Return the center (average signal) for a maximum.

Parameters

i	maximum index

References max_ctr.

const double * GExtremaFinder::GetMaximaAmplitudes ( ) const

inline

Returns the array of maxima integral amplitudes.

References max_amp.

Referenced by CopyData().

double * GExtremaFinder::GetMaximaAmplitudes ( )

inline

Returns the array of maxima integral amplitudes.

References max_amp.

const double * GExtremaFinder::GetMaximaAverages ( ) const

inline

Returns the array of maxima amplitudes.

References max_avg.

Referenced by CopyData().

double * GExtremaFinder::GetMaximaAverages ( )

inline

Returns the array of maxima average amplitudes.

References max_avg.

const u_int * GExtremaFinder::GetMaximaBins ( ) const

inline

Returns the array of maxima sample bin indexes.

References max_bin.

Referenced by CopyData().

u_int * GExtremaFinder::GetMaximaBins ( )

inline

Returns the array of maxima sample bin indexes.

References max_bin.

const double * GExtremaFinder::GetMaximaCenters ( ) const

inline

Returns the array of maxima centers (average signal position).

References max_ctr.

Referenced by CopyData().

double * GExtremaFinder::GetMaximaCenters ( )

inline

Returns the array of maxima centers (average signal position).

References max_ctr.

u_int GExtremaFinder::GetMaximaNum ( ) const

inline

Returns the number of maxima.

References max_num.

Referenced by CopyData().

const double * GExtremaFinder::GetMaximaPositions ( ) const

inline

Returns the array of maxima positions.

References max_pos.

Referenced by CopyData().

double * GExtremaFinder::GetMaximaPositions ( )

inline

Returns the array of maxima positions.

References max_pos.

const double * GExtremaFinder::GetMaximaValues ( ) const

inline

Returns the array of maxima values.

References max_val.

Referenced by CopyData().

double * GExtremaFinder::GetMaximaValues ( )

inline

Returns the array of maxima values.

References max_val.

u_int GExtremaFinder::GetMaxNextMinBin ( u_int  i ) const

inline

Return the sample bin index of the minimum after a maximum.

Parameters

i	maximum index

References max_next_min_bin.

double GExtremaFinder::GetMaxNextMinPos ( u_int  i ) const

inline

Return the minimum position after a maximum.

Parameters

i	maximum index

References max_next_min_pos.

double GExtremaFinder::GetMaxNextMinVal ( u_int  i ) const

inline

Return the value of the minimum after a maximum.

Parameters

i	maximum index

References max_next_min_val.

double GExtremaFinder::GetMaxPosition ( u_int  i ) const

inline

Return the position a maximum.

Parameters

i	maximum index

References max_pos.

u_int GExtremaFinder::GetMaxPrevMinBin ( u_int  i ) const

inline

Return the sample bin index of the minimum before a maximum.

Parameters

i	maximum index

References max_prev_min_bin.

double GExtremaFinder::GetMaxPrevMinPos ( u_int  i ) const

inline

Return the minimum position before a maximum.

Parameters

i	maximum index

References max_prev_min_pos.

double GExtremaFinder::GetMaxPrevMinVal ( u_int  i ) const

inline

Return the value of the minimum before a maximum.

Parameters

i	maximum index

References max_prev_min_val.

double GExtremaFinder::GetMaxValue ( u_int  i ) const

inline

Return the signal value for a maximum.

Parameters

i	maximum index

References max_val.

const GRealSampleFFT * GExtremaFinder::GetSample ( ) const

inline

Return the sample.

References sample_ptr.

GRealSampleFFT * GExtremaFinder::GetSample ( )

inline

Return the sample.

References sample_ptr.

GExtremaFinder::GObjectV ( GExtremaFinder  )

private

Macro from GCpp library that defines the following functions:

• ClassName(): return the real class name of the object
• StaticClassName(): return the used class name of the object (that may be a base class of the real object).
• IsInstanceOf<T>(): return true if the current object is an instance of the template class name argument
• Clone(): return an allocated copy of the object.

int GExtremaFinder::InitData ( u_int  n, double *  data, double  dt = 1.  )

virtual

Initialization of the extrema finder from an array of values. A sample is created locally from the data.

Parameters

n	requested size of arrays
data	data array
dt	sampling time step

References GLogWarning().

Referenced by Analyse(), CopyData(), GExtremaFinder(), and InitData().

int GExtremaFinder::InitData ( GRealSampleFFT *  sptr )

virtual

Initialization of the extrema finder from a sample pointer. The data sample is adopted by the class and delete with it.

Parameters

sptr	pointer to the data sample

References GLogWarning(), InitData(), sample_local, and sample_ptr.

int GExtremaFinder::InitData ( GRealSampleFFT &  s )

virtual

Initialization of the extrema finder from an external sample. The data sample pointer is set and considered external.

Parameters

s	data sample

References alloc_size, ClearData(), deriv_ptr, extr_bin, extr_max, extr_pos, extr_val, GBaseSampleFFT::GetSamplesNumber(), max_amp, max_avg, max_bin, max_ctr, max_next_min_bin, max_next_min_pos, max_next_min_val, max_pos, max_prev_min_bin, max_prev_min_pos, max_prev_min_val, max_val, ResetData(), sample_local, and sample_ptr.

bool GExtremaFinder::IsSampleLocal ( ) const

inline

Return true if the data sample is defined locally.

References sample_local.

Referenced by CopyData().

GExtremaFinder & GExtremaFinder::operator=

(

const GExtremaFinder &

original

)

Affectation operator.

Parameters

original

object to be copied

References CopyData().

void GExtremaFinder::ResetData ( )

virtual

Fonctions that deletes the data arrays and resets the analysis.

References alloc_size, analyzed, deriv_ptr, extr_bin, extr_max, extr_num, extr_pos, extr_val, max_amp, max_avg, max_bin, max_ctr, max_next_min_bin, max_next_min_pos, max_next_min_val, max_num, max_pos, max_prev_min_bin, max_prev_min_pos, max_prev_min_val, max_val, sample_local, and sample_ptr.

Referenced by InitData(), and ~GExtremaFinder().

void GExtremaFinder::SetMaximaLowThreshold ( double  thr )

inlinevirtual

Set the use of a low threshold for maxima analysis (the threshold value can be 0 or less).

Parameters

thr	low signal threshold for maxima analysis

References max_thr_low, and max_thr_use.

Referenced by AnalyseMaxima().

void GExtremaFinder::UnsetMaximaLowThreshold ( )

inlinevirtual

Unset the use of a low threshold for maxima analysis.

References max_thr_use.

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

• GExtremaFinder.hh
• GExtremaFinder.cpp
• GExtremaFinder.icc