cKSplit Class Reference

#include <cksplit.h>

Description

Implements k-split, an adaptive histogram-like density estimation algorithm. During result collection, k-split will dynamically subdivide "busy" bins (ones that collect a large number of observations), thereby refining the resolution of the histogram where needed.

The histogram produced by k-split will be an approximation, because the algorithm has no information on to divide up observations collected into a bin before it was split. Nevertheless, for stationary distributions, k-split usually produces a superior estimate of the distribution than uniform-bin histograms. If the distribution changes over time, and especially if it shows a distinct (increasing or decreasing) trend, k-split's estimate often contains artifacts that are not part of the input distribution.

See also

Iterator Grid

Inheritance diagram for cKSplit:

Classes
struct	Grid
	Supporting struct for cKSplit. Represents one grid in the k-split data structure. More...
class	Iterator
	Walks along cells of the distribution stored in a cKSplit object. More...

Public Types
typedef int(*	CritFunc) (const cKSplit &, cKSplit::Grid &, int, double *)
typedef double(*	DivFunc) (const cKSplit &, cKSplit::Grid &, double, double *)
Public Types inherited from cPrecollectionBasedDensityEst

Public Member Functions
Constructors, destructor, assignment.
	cKSplit (const char *name=nullptr, bool weighted=false)
	cKSplit (const cKSplit &r)
virtual	~cKSplit ()
cKSplit &	operator= (const cKSplit &res)
Redefined cObject member functions.
virtual cKSplit *	dup () const override
virtual void	parsimPack (cCommBuffer *buffer) const override
virtual void	parsimUnpack (cCommBuffer *buffer) override
Redefined member functions from cStatistic and its subclasses.
virtual void	setUpBins () override
virtual int	getNumBins () const override
virtual double	getBinEdge (int k) const override
virtual double	getBinValue (int k) const override
virtual void	merge (const cStatistic *other) override
virtual void	saveToFile (FILE *) const override
virtual void	loadFromFile (FILE *) override
Configuring the k-split algorithm.
void	setCritFunc (CritFunc _critfunc, double *_critdata)
void	setDivFunc (DivFunc _divfunc, double *_divdata)
void	setRangeExtension (bool enabled)
Querying the k-split data structure.
int	getTreeDepth () const
int	getTreeDepth (Grid &grid) const
double	getRealCellValue (Grid &grid, int cell) const
void	printGrids () const
Grid &	getGrid (int k) const
Grid &	getRootGrid () const
Public Member Functions inherited from cPrecollectionBasedDensityEst
	cPrecollectionBasedDensityEst (const cPrecollectionBasedDensityEst &other)
	cPrecollectionBasedDensityEst (const char *name=nullptr, bool weighted=false)
virtual	~cPrecollectionBasedDensityEst ()
cPrecollectionBasedDensityEst &	operator= (const cPrecollectionBasedDensityEst &res)
virtual void	collect (double value) override
virtual void	collectWeighted (double value, double weight) override
virtual void	clear () override
virtual void	setRange (double lower, double upper)
virtual void	setRangeAuto (int numPrecollect=100, double rangeExtensionFactor=2.0)
virtual void	setRangeAutoLower (double upper, int numPrecollect=100, double rangeExtensionFactor=2.0)
virtual void	setRangeAutoUpper (double lower, int numPrecollect=100, double rangeExtensionFactor=2.0)
virtual void	setNumPrecollectedValues (int numPrecollect)
virtual int	getNumPrecollectedValues () const
virtual double	getRangeExtensionFactor () const
virtual bool	binsAlreadySetUp () const override
virtual int64_t	getNumUnderflows () const override
virtual int64_t	getNumOverflows () const override
virtual double	getUnderflowSumWeights () const override
virtual double	getOverflowSumWeights () const override
Public Member Functions inherited from cAbstractHistogram
	cAbstractHistogram (const cAbstractHistogram &other)
	cAbstractHistogram (const char *name=nullptr, bool weighted=false)
virtual	~cAbstractHistogram ()
cAbstractHistogram &	operator= (const cAbstractHistogram &res)
virtual double	getBinPDF (int k) const
virtual Bin	getBinInfo (int k) const
virtual double	getPDF (double x) const
virtual double	getCDF (double x) const
virtual double	draw () const override
virtual _OPPDEPRECATED bool	isTransformed () const final
virtual _OPPDEPRECATED void	transform () final
virtual _OPPDEPRECATED int	getNumCells () const final
virtual _OPPDEPRECATED double	getBasepoint (int k) const final
virtual _OPPDEPRECATED double	getCellValue (int k) const final
virtual _OPPDEPRECATED double	getCellPDF (int k) const final
virtual _OPPDEPRECATED int64_t	getUnderflowCell () const final
virtual _OPPDEPRECATED int64_t	getOverflowCell () const final
virtual _OPPDEPRECATED Bin	getCellInfo (int k) const final
Public Member Functions inherited from cStdDev
	cStdDev (const cStdDev &r)
	cStdDev (const char *name=nullptr, bool weighted=false)
virtual	~cStdDev ()
cStdDev &	operator= (const cStdDev &res)
virtual std::string	str () const override
virtual bool	isWeighted () const override
virtual int64_t	getCount () const override
virtual double	getSum () const override
virtual double	getSqrSum () const override
virtual double	getMin () const override
virtual double	getMax () const override
virtual double	getMean () const override
virtual double	getStddev () const override
virtual double	getVariance () const override
virtual double	getSumWeights () const override
virtual double	getWeightedSum () const override
virtual double	getSqrSumWeights () const override
virtual double	getWeightedSqrSum () const override
Public Member Functions inherited from cStatistic
	cStatistic (const cStatistic &r)
	cStatistic (const char *name=nullptr)
virtual	~cStatistic ()
cStatistic &	operator= (const cStatistic &res)
virtual void	collect (SimTime value)
virtual void	collectWeighted (SimTime value, double weight)
virtual void	collectWeighted (double value, SimTime weight)
virtual void	collectWeighted (SimTime value, SimTime weight)
virtual void	record ()
virtual void	recordWithUnit (const char *unit)
virtual void	recordAs (const char *name, const char *unit=nullptr)
virtual _OPPDEPRECATED double	getWeights () const final
virtual _OPPDEPRECATED void	collect2 (double value, double weight) final
virtual _OPPDEPRECATED void	collect2 (SimTime value, double weight) final
virtual _OPPDEPRECATED void	collect2 (double value, SimTime weight) final
virtual _OPPDEPRECATED void	collect2 (SimTime value, SimTime weight) final
virtual _OPPDEPRECATED double	random () const final
virtual _OPPDEPRECATED void	clearResult () final
Public Member Functions inherited from cRandom
	cRandom (cRNG *rng)
	cRandom (const char *name=nullptr, cRNG *rng=nullptr)
virtual	~cRandom ()
virtual void	setRNG (cRNG *rng)
cRNG *	getRNG () const
Public Member Functions inherited from cOwnedObject
	cOwnedObject ()
	cOwnedObject (const char *name, bool namepooling=true)
	cOwnedObject (const cOwnedObject &obj)
virtual	~cOwnedObject ()
cOwnedObject &	operator= (const cOwnedObject &o)
virtual cObject *	getOwner () const override
virtual bool	isOwnedObject () const override
virtual bool	isSoftOwner () const
Public Member Functions inherited from cNamedObject
	cNamedObject ()
	cNamedObject (const char *name, bool namepooling=true)
	cNamedObject (const cNamedObject &obj)
virtual	~cNamedObject ()
cNamedObject &	operator= (const cNamedObject &o)
virtual void	setName (const char *s)
virtual const char *	getName () const override
virtual void	setNamePooling (bool b)
virtual bool	getNamePooling ()
Public Member Functions inherited from cObject
	cObject ()
	cObject (const cObject &other)
virtual	~cObject ()
virtual const char *	getClassName () const
bool	isName (const char *s) const
virtual const char *	getFullName () const
virtual std::string	getFullPath () const
const cObject *	getThisPtr () const
virtual _OPPDEPRECATED std::string	info () const
virtual _OPPDEPRECATED std::string	detailedInfo () const
virtual void	forEachChild (cVisitor *v)
cObject *	findObject (const char *name, bool deep=true)
void	copyNotSupported () const

Protected Member Functions
virtual void	collectIntoHistogram (double val) override
virtual void	collectWeightedIntoHistogram (double value, double weight) override
Protected Member Functions inherited from cPrecollectionBasedDensityEst
virtual void	setupRange ()
Protected Member Functions inherited from cObject
virtual void	take (cOwnedObject *obj)
virtual void	drop (cOwnedObject *obj)
void	dropAndDelete (cOwnedObject *obj)

Additional Inherited Members
Static Public Member Functions inherited from cOwnedObject
static long	getTotalObjectCount ()
static long	getLiveObjectCount ()
static void	resetObjectCounters ()
static cDefaultList *	getDefaultOwner ()

Constructor & Destructor Documentation

cKSplit ( const char *  name = nullptr, bool  weighted = false  )

explicit

Constructor.

cKSplit

(

const cKSplit &

r

)

Copy constructor.

virtual ~cKSplit ( )

virtual

Destructor.

Member Function Documentation

cKSplit& operator=

(

const cKSplit &

res

)

Assignment operator. The name member is not copied; see cNamedObject's operator=() for more details.

virtual cKSplit* dup ( ) const

inlineoverridevirtual

Creates and returns an exact copy of this object. See cObject for more details.

Reimplemented from cStdDev.

virtual void parsimPack ( cCommBuffer *  buffer ) const

overridevirtual

Serializes the object into an MPI send buffer. Used by the simulation kernel for parallel execution. See cObject for more details.

Reimplemented from cPrecollectionBasedDensityEst.

virtual void parsimUnpack ( cCommBuffer *  buffer )

overridevirtual

Deserializes the object from an MPI receive buffer. Used by the simulation kernel for parallel execution. See cObject for more details.

Reimplemented from cPrecollectionBasedDensityEst.

virtual void collectIntoHistogram ( double  val )

overrideprotectedvirtual

Called internally by collect(), this method updates the k-split data structure with the new value.

Implements cPrecollectionBasedDensityEst.

virtual void collectWeightedIntoHistogram ( double  value, double  weight  )

overrideprotectedvirtual

Called internally by collect().

Implements cPrecollectionBasedDensityEst.

virtual void setUpBins ( )

overridevirtual

Transforms the table of pre-collected values into the k-split data structure.

Implements cAbstractHistogram.

virtual int getNumBins ( ) const

overridevirtual

Returns the number of histogram cells used.

Implements cAbstractHistogram.

virtual double getBinEdge ( int  k ) const

overridevirtual

Returns the kth cell boundary.

Implements cAbstractHistogram.

virtual double getBinValue ( int  k ) const

overridevirtual

Returns the number of observations that fell into the kth histogram cell.

Implements cAbstractHistogram.

virtual void merge ( const cStatistic *  other )

overridevirtual

Merging is not supported by this class. This method throws an error.

Reimplemented from cPrecollectionBasedDensityEst.

virtual void saveToFile ( FILE *  ) const

overridevirtual

Writes the contents of the object into a text file.

Reimplemented from cPrecollectionBasedDensityEst.

virtual void loadFromFile ( FILE *  )

overridevirtual

Reads the object data from a file, in the format written out by saveToFile().

Reimplemented from cPrecollectionBasedDensityEst.

void setCritFunc	(	CritFunc	_critfunc,
		double *	_critdata
	)

Configures the k-split algorithm by supplying a custom split criterion function.

void setDivFunc	(	DivFunc	_divfunc,
		double *	_divdata
	)

Configures the k-split algorithm by supplying a custom cell division function.

void setRangeExtension

(

bool

enabled

)

Enables/disables range extension. If range extension is enabled, a new observation that falls outside the k-split range (i.e. outside the root grid) will cause the range to be expanded (i.e. new root getGrid(s) to be placed above the current root grid). If range extension is disabled, such observations will simply be counted as underflows or overflows.

int getTreeDepth

(

)

const

Returns the depth of the k-split tree.

int getTreeDepth

(

Grid &

grid

)

const

Returns the depth of the k-split tree measured from the specified grid.

double getRealCellValue	(	Grid &	grid,
		int	cell
	)		const

Returns the actual amount of observations in cell 'cell' of 'grid'. This is not necessarily an integer value because of previous cell splits.

void printGrids

(

)

const

Dumps the contents of the k-split data structure to EV.

Grid& getGrid ( int  k ) const

inline

Returns the kth grid in the k-split data structure.

Grid& getRootGrid ( ) const

inline

Returns the root grid of the k-split data structure.

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

• cksplit.h