Advanced 1-dimensional orthogonal transform functions.

Author: Miroslav Morhac

Class to carry out transforms of 1D spectra, its filtering and enhancement. It allows to calculate classic Fourier, Cosine, Sin, Hartley, Walsh, Haar transforms as well as mixed transforms (Fourier- Walsh, Fourier-Haar, Walsh-Haar, Cosine-Walsh, Cosine-Haar, Sin-Walsh and Sin-Haar). All the transforms are fast.

The algorithms in this class have been published in the following references:

C.V. Hampton, B. Lian, Wm. C. McHarris: Fast-Fourier-transform spectral enhancement techniques for gamma-ray spectroscopy.NIM A353(1994) 280-284.
Morhac M., Matousek V., New adaptive Cosine-Walsh transform and its application to nuclear data compression, IEEE Transactions on Signal Processing 48 (2000) 2693.
Morhac M., Matousek V., Data compression using new fast adaptive Cosine-Haar transforms, Digital Signal Processing 8 (1998) 63.
Morhac M., Matousek V.: Multidimensional nuclear data compression using fast adaptive Walsh-Haar transform. Acta Physica Slovaca 51 (2001) 307.

Definition at line 20 of file TSpectrumTransform.h.

Public Types
enum	{ kTransformHaar =0, kTransformWalsh =1, kTransformCos =2, kTransformSin =3, kTransformFourier =4, kTransformHartley =5, kTransformFourierWalsh =6, kTransformFourierHaar =7, kTransformWalshHaar =8, kTransformCosWalsh =9, kTransformCosHaar =10, kTransformSinWalsh =11, kTransformSinHaar =12, kTransformForward =0, kTransformInverse =1 }

Public Types inherited from TObject
enum	EStatusBits { kCanDelete = BIT(0), kMustCleanup = BIT(3), kObjInCanvas = BIT(3), kIsReferenced = BIT(4), kHasUUID = BIT(5), kCannotPick = BIT(6), kNoContextMenu = BIT(8), kInvalidObject = BIT(13) }

enum	{ kIsOnHeap = 0x01000000, kNotDeleted = 0x02000000, kZombie = 0x04000000, kBitMask = 0x00ffffff }

enum	{ kSingleKey = BIT(0), kOverwrite = BIT(1), kWriteDelete = BIT(2) }

Public Member Functions
	TSpectrumTransform ()

	TSpectrumTransform (Int_t size)
	the constructor creates TSpectrumTransform object. More...

virtual	~TSpectrumTransform ()
	Destructor. More...

void	Enhance (const Double_t source, Double_t destVector)
	This function transforms the source spectrum. More...

void	FilterZonal (const Double_t source, Double_t destVector)
	This function transforms the source spectrum. More...

void	SetDirection (Int_t direction)
	This function sets the direction of the transform: More...

void	SetEnhanceCoeff (Double_t enhanceCoeff)
	This function sets the enhancement coefficient: More...

void	SetFilterCoeff (Double_t filterCoeff)
	This function sets the filter coefficient: More...

void	SetRegion (Int_t xmin, Int_t xmax)
	This function sets the filtering or enhancement region: More...

void	SetTransformType (Int_t transType, Int_t degree)
	This function sets the following parameters for transform: More...

void	Transform (const Double_t source, Double_t destVector)
	This function transforms the source spectrum. More...

Public Member Functions inherited from TNamed
	TNamed ()

	TNamed (const char name, const char title)

	TNamed (const TString &name, const TString &title)

	TNamed (const TNamed &named)

TNamed &	operator= (const TNamed &rhs)
	TNamed assignment operator. More...

virtual	~TNamed ()

virtual void	Clear (Option_t *option="")
	Set name and title to empty strings (""). More...

virtual TObject *	Clone (const char *newname="") const
	Make a clone of an object using the Streamer facility. More...

virtual Int_t	Compare (const TObject *obj) const
	Compare two TNamed objects. More...

virtual void	Copy (TObject &named) const
	Copy this to obj. More...

virtual void	FillBuffer (char *&buffer)
	Encode TNamed into output buffer. More...

virtual const char *	GetName () const
	Returns name of object. More...

virtual const char *	GetTitle () const
	Returns title of object. More...

virtual ULong_t	Hash () const
	Return hash value for this object. More...

virtual Bool_t	IsSortable () const

virtual void	SetName (const char *name)
	Change (i.e. More...

virtual void	SetNameTitle (const char name, const char title)
	Change (i.e. set) all the TNamed parameters (name and title). More...

virtual void	SetTitle (const char *title="")
	Change (i.e. set) the title of the TNamed. More...

virtual void	ls (Option_t *option="") const
	List TNamed name and title. More...

virtual void	Print (Option_t *option="") const
	Print TNamed name and title. More...

virtual Int_t	Sizeof () const
	Return size of the TNamed part of the TObject. More...

Public Member Functions inherited from TObject
	TObject ()

	TObject (const TObject &object)
	TObject copy ctor. More...

TObject &	operator= (const TObject &rhs)
	TObject assignment operator. More...

virtual	~TObject ()
	TObject destructor. More...

virtual void	AppendPad (Option_t *option="")
	Append graphics object to current pad. More...

virtual void	Browse (TBrowser *b)
	Browse object. May be overridden for another default action. More...

virtual const char *	ClassName () const
	Returns name of class to which the object belongs. More...

virtual void	Delete (Option_t *option="")
	Delete this object. More...

virtual Int_t	DistancetoPrimitive (Int_t px, Int_t py)
	Computes distance from point (px,py) to the object. More...

virtual void	Draw (Option_t *option="")
	Default Draw method for all objects. More...

virtual void	DrawClass () const
	Draw class inheritance tree of the class to which this object belongs. More...

virtual TObject *	DrawClone (Option_t *option="") const
	Draw a clone of this object in the current pad. More...

virtual void	Dump () const
	Dump contents of object on stdout. More...

virtual void	Execute (const char method, const char params, Int_t *error=0)
	Execute method on this object with the given parameter string, e.g. More...

virtual void	Execute (TMethod method, TObjArray params, Int_t *error=0)
	Execute method on this object with parameters stored in the TObjArray. More...

virtual void	ExecuteEvent (Int_t event, Int_t px, Int_t py)
	Execute action corresponding to an event at (px,py). More...

virtual TObject *	FindObject (const char *name) const
	Must be redefined in derived classes. More...

virtual TObject *	FindObject (const TObject *obj) const
	Must be redefined in derived classes. More...

virtual Option_t *	GetDrawOption () const
	Get option used by the graphics system to draw this object. More...

virtual UInt_t	GetUniqueID () const
	Return the unique object id. More...

virtual const char *	GetIconName () const
	Returns mime type name of object. More...

virtual Option_t *	GetOption () const

virtual char *	GetObjectInfo (Int_t px, Int_t py) const
	Returns string containing info about the object at position (px,py). More...

virtual Bool_t	HandleTimer (TTimer *timer)
	Execute action in response of a timer timing out. More...

virtual Bool_t	InheritsFrom (const char *classname) const
	Returns kTRUE if object inherits from class "classname". More...

virtual Bool_t	InheritsFrom (const TClass *cl) const
	Returns kTRUE if object inherits from TClass cl. More...

virtual void	Inspect () const
	Dump contents of this object in a graphics canvas. More...

virtual Bool_t	IsFolder () const
	Returns kTRUE in case object contains browsable objects (like containers or lists of other objects). More...

virtual Bool_t	IsEqual (const TObject *obj) const
	Default equal comparison (objects are equal if they have the same address in memory). More...

Bool_t	IsOnHeap () const

Bool_t	IsZombie () const

virtual Bool_t	Notify ()
	This method must be overridden to handle object notification. More...

virtual void	Paint (Option_t *option="")
	This method must be overridden if a class wants to paint itself. More...

virtual void	Pop ()
	Pop on object drawn in a pad to the top of the display list. More...

virtual Int_t	Read (const char *name)
	Read contents of object with specified name from the current directory. More...

virtual void	RecursiveRemove (TObject *obj)
	Recursively remove this object from a list. More...

virtual void	SaveAs (const char filename="", Option_t option="") const
	Save this object in the file specified by filename. More...

virtual void	SavePrimitive (std::ostream &out, Option_t *option="")
	Save a primitive as a C++ statement(s) on output stream "out". More...

virtual void	SetDrawOption (Option_t *option="")
	Set drawing option for object. More...

virtual void	SetUniqueID (UInt_t uid)
	Set the unique object id. More...

virtual void	UseCurrentStyle ()
	Set current style settings in this object This function is called when either TCanvas::UseCurrentStyle or TROOT::ForceStyle have been invoked. More...

virtual Int_t	Write (const char *name=0, Int_t option=0, Int_t bufsize=0)
	Write this object to the current directory. More...

virtual Int_t	Write (const char *name=0, Int_t option=0, Int_t bufsize=0) const
	Write this object to the current directory. More...

void *	operator new (size_t sz)

void *	operator new[] (size_t sz)

void *	operator new (size_t sz, void *vp)

void *	operator new[] (size_t sz, void *vp)

void	operator delete (void *ptr)
	Operator delete. More...

void	operator delete[] (void *ptr)
	Operator delete []. More...

void	SetBit (UInt_t f, Bool_t set)
	Set or unset the user status bits as specified in f. More...

void	SetBit (UInt_t f)

void	ResetBit (UInt_t f)

Bool_t	TestBit (UInt_t f) const

Int_t	TestBits (UInt_t f) const

void	InvertBit (UInt_t f)

virtual void	Info (const char method, const char msgfmt,...) const
	Issue info message. More...

virtual void	Warning (const char method, const char msgfmt,...) const
	Issue warning message. More...

virtual void	Error (const char method, const char msgfmt,...) const
	Issue error message. More...

virtual void	SysError (const char method, const char msgfmt,...) const
	Issue system error message. More...

virtual void	Fatal (const char method, const char msgfmt,...) const
	Issue fatal error message. More...

void	AbstractMethod (const char *method) const
	Use this method to implement an "abstract" method that you don't want to leave purely abstract. More...

void	MayNotUse (const char *method) const
	Use this method to signal that a method (defined in a base class) may not be called in a derived class (in principle against good design since a child class should not provide less functionality than its parent, however, sometimes it is necessary). More...

void	Obsolete (const char method, const char asOfVers, const char *removedFromVers) const
	Use this method to declare a method obsolete. More...

Protected Member Functions
void	BitReverse (Double_t *working_space, Int_t num)
	This function carries out bit-reverse reordering of data Function parameters: More...

void	BitReverseHaar (Double_t *working_space, Int_t shift, Int_t num, Int_t start)
	This function carries out bit-reverse reordering for Haar transform Function parameters: More...

void	Fourier (Double_t *working_space, Int_t num, Int_t hartley, Int_t direction, Int_t zt_clear)
	This function calculates Fourier based transform of a part of data Function parameters: More...

Int_t	GeneralExe (Double_t *working_space, Int_t zt_clear, Int_t num, Int_t degree, Int_t type)
	This function calculates generalized (mixed) transforms of different degrees Function parameters: More...

Int_t	GeneralInv (Double_t *working_space, Int_t num, Int_t degree, Int_t type)
	This function calculates inverse generalized (mixed) transforms Function parameters: More...

void	Haar (Double_t *working_space, Int_t num, Int_t direction)
	This function calculates Haar transform of a part of data Function parameters: More...

void	Walsh (Double_t *working_space, Int_t num)
	This function calculates Walsh transform of a part of data Function parameters: More...

Protected Member Functions inherited from TObject
void	MakeZombie ()

virtual void	DoError (int level, const char location, const char fmt, va_list va) const
	Interface to ErrorHandler (protected). More...

Protected Attributes
Int_t	fSize
	length of transformed data More...

Int_t	fTransformType
	type of transformation (Haar, Walsh, Cosine, Sine, Fourier, Hartley, Fourier-Walsh, Fourier-Haar, Walsh-Haar, Cosine-Walsh, Cosine-Haar, Sine-Walsh, Sine-Haar) More...

Int_t	fDegree
	degree of mixed transform, applies only for Fourier-Walsh, Fourier-Haar, Walsh-Haar, Cosine-Walsh, Cosine-Haar, Sine-Walsh, Sine-Haar transforms More...

Int_t	fDirection
	forward or inverse transform More...

Int_t	fXmin
	first channel of filtered or enhanced region More...

Int_t	fXmax
	last channel of filtered or enhanced region More...

Double_t	fFilterCoeff
	value set in the filtered region More...

Double_t	fEnhanceCoeff
	multiplication coefficient applied in enhanced region; More...

Protected Attributes inherited from TNamed
TString	fName

TString	fTitle

Additional Inherited Members
Static Public Member Functions inherited from TObject
static Long_t	GetDtorOnly ()
	Return destructor only flag. More...

static void	SetDtorOnly (void *obj)
	Set destructor only flag. More...

static Bool_t	GetObjectStat ()
	Get status of object stat flag. More...

static void	SetObjectStat (Bool_t stat)
	Turn on/off tracking of objects in the TObjectTable. More...

#include <TSpectrumTransform.h>

Inheritance diagram for TSpectrumTransform:

[legend]

Member Enumeration Documentation

anonymous enum

Enumerator
kTransformHaar
kTransformWalsh
kTransformCos
kTransformSin
kTransformFourier
kTransformHartley
kTransformFourierWalsh
kTransformFourierHaar
kTransformWalshHaar
kTransformCosWalsh
kTransformCosHaar
kTransformSinWalsh
kTransformSinHaar
kTransformForward
kTransformInverse

Definition at line 33 of file TSpectrumTransform.h.

Constructor & Destructor Documentation

TSpectrumTransform::TSpectrumTransform ( )

TSpectrumTransform::TSpectrumTransform ( Int_t size )

the constructor creates TSpectrumTransform object.

Its size must be > than zero and must be power of 2. It sets default transform type to be Cosine transform. Transform parameters can be changed using setter functions.

Definition at line 53 of file TSpectrumTransform.cxx.

TSpectrumTransform::~TSpectrumTransform ( )

virtual

Destructor.

Definition at line 84 of file TSpectrumTransform.cxx.

Member Function Documentation

void TSpectrumTransform::BitReverse	(	Double_t *	working_space,
		Int_t	num
	)

protected

This function carries out bit-reverse reordering of data Function parameters:

working_space-pointer to vector of processed data
num-length of processed data

Definition at line 226 of file TSpectrumTransform.cxx.

Referenced by Enhance(), FilterZonal(), and Transform().

void TSpectrumTransform::BitReverseHaar	(	Double_t *	working_space,
		Int_t	shift,
		Int_t	num,
		Int_t	start
	)

protected

This function carries out bit-reverse reordering for Haar transform Function parameters:

working_space-pointer to vector of processed data
shift-shift of position of processing
start-initial position of processed data
num-length of processed data

Definition at line 385 of file TSpectrumTransform.cxx.

Referenced by Enhance(), FilterZonal(), and Transform().

void TSpectrumTransform::Enhance	(	const Double_t *	source,
		Double_t *	destVector
	)

This function transforms the source spectrum.

The calling program should fill in input parameters. Then it multiplies transformed coefficients in the given region (fXmin, fXmax) by the given fEnhanceCoeff and transforms it back Processed data are written into dest spectrum.

Function parameters:

source-pointer to the vector of source spectrum, its length should be size except for inverse FOURIER, FOUR-WALSh, FOUR-HAAR transform. These need 2*size length to supply real and imaginary coefficients.
destVector-pointer to the vector of dest data, its length should be size except for direct FOURIER, FOUR-WALSh, FOUR-HAAR. These need 2*size length to store real and imaginary coefficients

Example - script Enhance.c:

Fig. 1 Original spectrum (black line) and enhanced spectrum (red line) using Cosine transform (channels 0-1024 were multiplied by 2)

Script:

Example to illustrate Enhance function (class TSpectrumTransform). To execute this example, do:

root > .x Enhance.C

void Enhance() {
   Int_t i;
   Double_t nbins = 4096;
   Double_t xmin = 0;
   Double_t xmax = (Double_t)nbins;
   Double_t * source = new Double_t[nbins];
   Double_t * dest = new Double_t[nbins];
   TH1F *h = new TH1F("h","Enhancement using Cosine transform",nbins,xmin,xmax);
   TH1F *d = new TH1F("d","",nbins,xmin,xmax);
   TFile *f = new TFile("spectra/TSpectrum.root");
   h=(TH1F*) f->Get("transform1;1");
   for (i = 0; i < nbins; i++) source[i]=h->GetBinContent(i + 1);
   TCanvas *Transform1 = gROOT->GetListOfCanvases()->FindObject("Transform1");
   if (!Transform1) Transform1 = new TCanvas("Transform","Transform1",10,10,1000,700);
   h->SetAxisRange(700,1024);
   h->Draw("L");
   TSpectrum *s = new TSpectrum();
   TSpectrumTransform *t = new TSpectrumTransform(4096);
   t->SetTransformType(t->kTransformCos,0);
   t->SetRegion(0, 1024);
   t->SetEnhanceCoeff(2);
   t->Enhance(source,dest);
   for (i = 0; i < nbins; i++) d->SetBinContent(i + 1,dest[i]);
   d->SetLineColor(kRed);
   d->Draw("SAME L");
}

Definition at line 1778 of file TSpectrumTransform.cxx.

void TSpectrumTransform::FilterZonal	(	const Double_t *	source,
		Double_t *	destVector
	)

This function transforms the source spectrum.

The calling program should fill in input parameters. Then it sets transformed coefficients in the given region (fXmin, fXmax) to the given fFilterCoeff and transforms it back. Filtered data are written into dest spectrum.

Function parameters:

source-pointer to the vector of source spectrum, its length should be size except for inverse FOURIER, FOUR-WALSH, FOUR-HAAR transform. These need 2*size length to supply real and imaginary coefficients.
destVector-pointer to the vector of dest data, its length should be size except for direct FOURIER, FOUR-WALSH, FOUR-HAAR. These need 2*size length to store real and imaginary coefficients

Example - script Filter.c:

Fig. 1 Original spectrum (black line) and filtered spectrum (red line) using Cosine transform and zonal filtration (channels 2048-4095 were set to 0)

Script:

Example to illustrate FilterZonal function (class TSpectrumTransform). To execute this example, do:

root > .x Filter.C

#include <TSpectrum>
#include <TSpectrumTransform>
void Filter() {
   Int_t i;
   Double_t nbins = 4096;
   Double_t xmin = 0;
   Double_t xmax = (Double_t)nbins;
   Double_t * source = new Double_t[nbins];
   Double_t * dest = new Double_t[nbins];
   TH1F *h = new TH1F("h","Zonal filtering using Cosine transform",nbins,xmin,xmax);
   TH1F *d = new TH1F("d","",nbins,xmin,xmax);
   TFile *f = new TFile("spectra/TSpectrum.root");
   h=(TH1F*) f->Get("transform1;1");
   for (i = 0; i < nbins; i++) source[i]=h->GetBinContent(i + 1);
   TCanvas *Transform1 = gROOT->GetListOfCanvases()->FindObject("Transform1");
   if (!Transform1) Transform1 = new TCanvas("Transform","Transform1",10,10,1000,700);
   h->SetAxisRange(700,1024);
   h->Draw("L");
   TSpectrum *s = new TSpectrum();
   TSpectrumTransform *t = new TSpectrumTransform(4096);
   t->SetTransformType(t->kTransformCos,0);
   t->SetRegion(2048, 4095);
   t->FilterZonal(source,dest);
   for (i = 0; i < nbins; i++) d->SetBinContent(i + 1,dest[i]);
   d->SetLineColor(kRed);
   d->Draw("SAME L");
}

Definition at line 1268 of file TSpectrumTransform.cxx.

void TSpectrumTransform::Fourier	(	Double_t *	working_space,
		Int_t	num,
		Int_t	hartley,
		Int_t	direction,
		Int_t	zt_clear
	)

protected

This function calculates Fourier based transform of a part of data Function parameters:

working_space-pointer to vector of transformed data
num-length of processed data
hartley-1 if it is Hartley transform, 0 otherwise
direction-forward or inverse transform

Definition at line 264 of file TSpectrumTransform.cxx.

Referenced by Enhance(), FilterZonal(), and Transform().

int TSpectrumTransform::GeneralExe	(	Double_t *	working_space,
		Int_t	zt_clear,
		Int_t	num,
		Int_t	degree,
		Int_t	type
	)

protected

This function calculates generalized (mixed) transforms of different degrees Function parameters:

working_space-pointer to vector of transformed data
zt_clear-flag to clear imaginary data before staring
num-length of processed data
degree-degree of transform (see manual)
type-type of mixed transform (see manual)

Definition at line 430 of file TSpectrumTransform.cxx.

Referenced by Enhance(), FilterZonal(), and Transform().

int TSpectrumTransform::GeneralInv	(	Double_t *	working_space,
		Int_t	num,
		Int_t	degree,
		Int_t	type
	)

protected

This function calculates inverse generalized (mixed) transforms Function parameters:

working_space-pointer to vector of transformed data
num-length of processed data
degree-degree of transform (see manual)
type-type of mixed transform (see manual)

Definition at line 546 of file TSpectrumTransform.cxx.

Referenced by Enhance(), FilterZonal(), and Transform().

void TSpectrumTransform::Haar	(	Double_t *	working_space,
		Int_t	num,
		Int_t	direction
	)

protected

This function calculates Haar transform of a part of data Function parameters:

working_space-pointer to vector of transformed data
num-length of processed data
direction-forward or inverse transform

Definition at line 95 of file TSpectrumTransform.cxx.

Referenced by Enhance(), FilterZonal(), and Transform().

void TSpectrumTransform::SetDirection ( Int_t direction )

This function sets the direction of the transform:

direction (forward or inverse)

Definition at line 2277 of file TSpectrumTransform.cxx.

void TSpectrumTransform::SetEnhanceCoeff ( Double_t enhanceCoeff )

This function sets the enhancement coefficient:

enhanceCoeff - after the transform the enhanced region (xmin, xmax) is multiplied by this coefficient. Applies only for enhancement operation.

Definition at line 2299 of file TSpectrumTransform.cxx.

void TSpectrumTransform::SetFilterCoeff ( Double_t filterCoeff )

This function sets the filter coefficient:

filterCoeff - after the transform the filtered region (xmin, xmax) is replaced by this coefficient. Applies only for filtereng operation.

Definition at line 2290 of file TSpectrumTransform.cxx.

void TSpectrumTransform::SetRegion	(	Int_t	xmin,
		Int_t	xmax
	)

This function sets the filtering or enhancement region:

xmin, xmax

Definition at line 2263 of file TSpectrumTransform.cxx.

void TSpectrumTransform::SetTransformType	(	Int_t	transType,
		Int_t	degree
	)

This function sets the following parameters for transform:

transType - type of transform (Haar, Walsh, Cosine, Sine, Fourier, Hartley, Fourier-Walsh, Fourier-Haar, Walsh-Haar, Cosine-Walsh, Cosine-Haar, Sine-Walsh, Sine-Haar)
degree - degree of mixed transform, applies only for Fourier-Walsh, Fourier-Haar, Walsh-Haar, Cosine-Walsh, Cosine-Haar, Sine-Walsh, Sine-Haar transforms

Definition at line 2236 of file TSpectrumTransform.cxx.

void TSpectrumTransform::Transform	(	const Double_t *	source,
		Double_t *	destVector
	)

This function transforms the source spectrum.

The calling program should fill in input parameters. Transformed data are written into dest spectrum.

Function parameters:

source-pointer to the vector of source spectrum, its length should be size except for inverse FOURIER, FOUR-WALSH, FOUR-HAAR transform. These need 2*size length to supply real and imaginary coefficients.
destVector-pointer to the vector of dest data, its length should be size except for direct FOURIER, FOUR-WALSH, FOUR-HAAR. These need 2*size length to store real and imaginary coefficients

Transform methods

Goal: to analyse experimental data using orthogonal transforms

orthogonal transforms can be successfully used for the processing of nuclear spectra (not only)
they can be used to remove high frequency noise, to increase signal-to-background ratio as well as to enhance low intensity components [1], to carry out e.g. Fourier analysis etc.
we have implemented the function for the calculation of the commonly used orthogonal transforms as well as functions for the filtration and enhancement of experimental data

References:

[1] C.V. Hampton, B. Lian, Wm. C. McHarris: Fast-Fourier-transform spectral enhancement techniques for gamma-ray spectroscopy. NIM A353 (1994) 280-284.

[2] Morhac; M., Matouoek V., New adaptive Cosine-Walsh transform and its application to nuclear data compression, IEEE Transactions on Signal Processing 48 (2000) 2693.

[3] Morhac; M., Matouoek V., Data compression using new fast adaptive Cosine-Haar transforms, Digital Signal Processing 8 (1998) 63.

[4] Morhac; M., Matouoek V.: Multidimensional nuclear data compression using fast adaptive Walsh-Haar transform. Acta Physica Slovaca 51 (2001) 307.

Example - script Transform.c:

Fig. 1 Original gamma-ray spectrum

Fig. 2 Transformed spectrum from Fig. 1 using Cosine transform

Script:

Example to illustrate Transform function (class TSpectrumTransform). To execute this example, do:

root > .x Transform.C

#include <TSpectrum>
#include <TSpectrumTransform>
void Transform() {
   Int_t i;
   Double_t nbins = 4096;
   Double_t xmin = 0;
   Double_t xmax = (Double_t)nbins;
   Double_t * source = new Double_t[nbins];
   Double_t * dest = new Double_t[nbins];
   TH1F *h = new TH1F("h","Transformed spectrum using Cosine transform",nbins,xmin,xmax);
   TFile *f = new TFile("spectra/TSpectrum.root");
   h=(TH1F*) f->Get("transform1;1");
   for (i = 0; i < nbins; i++) source[i]=h->GetBinContent(i + 1);
   TCanvas *Transform1 = gROOT->GetListOfCanvases()->FindObject("Transform1");
   if (!Transform1) Transform1 = new TCanvas("Transform","Transform1",10,10,1000,700);
   TSpectrum *s = new TSpectrum();
   TSpectrumTransform *t = new TSpectrumTransform(4096);
   t->SetTransformType(t->kTransformCos,0);
   t->SetDirection(t->kTransformForward);
   t->Transform(source,dest);
   for (i = 0; i < nbins; i++) h->SetBinContent(i + 1,dest[i]);
   h->SetLineColor(kRed);
   h->Draw("L");
}

Definition at line 740 of file TSpectrumTransform.cxx.

void TSpectrumTransform::Walsh	(	Double_t *	working_space,
		Int_t	num
	)

protected

This function calculates Walsh transform of a part of data Function parameters:

working_space-pointer to vector of transformed data
num-length of processed data

Definition at line 173 of file TSpectrumTransform.cxx.

Referenced by Enhance(), FilterZonal(), and Transform().

Member Data Documentation

Int_t TSpectrumTransform::fDegree

protected

degree of mixed transform, applies only for Fourier-Walsh, Fourier-Haar, Walsh-Haar, Cosine-Walsh, Cosine-Haar, Sine-Walsh, Sine-Haar transforms

Definition at line 25 of file TSpectrumTransform.h.

Referenced by Enhance(), FilterZonal(), SetTransformType(), Transform(), and TSpectrumTransform().

Int_t TSpectrumTransform::fDirection

protected

forward or inverse transform

Definition at line 26 of file TSpectrumTransform.h.

Referenced by SetDirection(), Transform(), and TSpectrumTransform().

Double_t TSpectrumTransform::fEnhanceCoeff

protected

multiplication coefficient applied in enhanced region;

Definition at line 30 of file TSpectrumTransform.h.

Referenced by Enhance(), SetEnhanceCoeff(), and TSpectrumTransform().

Double_t TSpectrumTransform::fFilterCoeff

protected

value set in the filtered region

Definition at line 29 of file TSpectrumTransform.h.

Referenced by FilterZonal(), SetFilterCoeff(), and TSpectrumTransform().

Int_t TSpectrumTransform::fSize

protected

length of transformed data

Definition at line 23 of file TSpectrumTransform.h.

Referenced by Enhance(), FilterZonal(), SetRegion(), SetTransformType(), Transform(), and TSpectrumTransform().

Int_t TSpectrumTransform::fTransformType

protected

type of transformation (Haar, Walsh, Cosine, Sine, Fourier, Hartley, Fourier-Walsh, Fourier-Haar, Walsh-Haar, Cosine-Walsh, Cosine-Haar, Sine-Walsh, Sine-Haar)

Definition at line 24 of file TSpectrumTransform.h.

Referenced by Enhance(), FilterZonal(), SetTransformType(), Transform(), and TSpectrumTransform().