One of the interface classes to the FFTW package, can be used directly or via the TVirtualFFT class.

Only the basic interface of FFTW is implemented. Computes complex input/output discrete Fourier transforms (DFT) in one or more dimensions. For the detailed information on the computed transforms please refer to the FFTW manual, chapter "What FFTW really computes".

How to use it:

Create an instance of TFFTComplex - this will allocate input and output arrays (unless an in-place transform is specified)
Run the Init() function with the desired flags and settings
Set the data (via SetPoints(), SetPoint() or SetPointComplex() functions)
Run the Transform() function
Get the output (via GetPoints(), GetPoint() or GetPointComplex() functions)
Repeat steps 3)-5) as needed

For a transform of the same size, but with different flags or sign, rerun the Init() function and continue with steps 3)-5)

NOTE:

running Init() function will overwrite the input array! Don't set any data before running the Init() function
FFTW computes unnormalized transform, so doing a transform followed by its inverse will lead to the original array scaled by the transform size

Definition at line 20 of file TFFTComplex.h.

Public Member Functions
	TFFTComplex ()
	default More...

	TFFTComplex (Int_t n, Bool_t inPlace)
	For 1d transforms Allocates memory for the input array, and, if inPlace = kFALSE, for the output array. More...

	TFFTComplex (Int_t ndim, Int_t *n, Bool_t inPlace=kFALSE)
	For multidim. More...

virtual	~TFFTComplex ()
	Destroys the data arrays and the plan. More...

virtual Int_t *	GetN () const

virtual Int_t	GetNdim () const

virtual void	GetPointComplex (const Int_t *ipoint, Double_t &re, Double_t &im, Bool_t fromInput=kFALSE) const
	For multidimensional transforms. Returns real and imaginary parts of the point #ipoint. More...

virtual void	GetPointComplex (Int_t ipoint, Double_t &re, Double_t &im, Bool_t fromInput=kFALSE) const
	returns real and imaginary parts of the point #ipoint More...

virtual Double_t	GetPointReal (const Int_t *, Bool_t) const

virtual Double_t	GetPointReal (Int_t, Bool_t) const

virtual void	GetPoints (Double_t *data, Bool_t fromInput=kFALSE) const
	Copies the output(or input) into the argument array. More...

virtual void	GetPointsComplex (Double_t *data, Bool_t fromInput=kFALSE) const
	Copies the output(input) into the argument array. More...

virtual void	GetPointsComplex (Double_t re, Double_t im, Bool_t fromInput=kFALSE) const
	Copies real and imaginary parts of the output (input) into the argument arrays. More...

virtual Double_t *	GetPointsReal (Bool_t) const

virtual Int_t	GetSign () const

virtual Int_t	GetSize () const

virtual Option_t *	GetTransformFlag () const

virtual Option_t *	GetType () const

virtual void	Init (Option_t flags, Int_t sign, const Int_t )
	Creates the fftw-plan. More...

virtual Bool_t	IsInplace () const

virtual void	SetPoint (const Int_t *ipoint, Double_t re, Double_t im=0)
	For multidim. transforms. Sets real and imaginary parts of point # ipoint. More...

virtual void	SetPoint (Int_t ipoint, Double_t re, Double_t im=0)
	sets real and imaginary parts of point # ipoint More...

virtual void	SetPointComplex (Int_t ipoint, TComplex &c)

virtual void	SetPoints (const Double_t *data)
	set all points. More...

virtual void	SetPointsComplex (const Double_t re, const Double_t im)
	set all points. the values are copied More...

virtual void	Transform ()
	Computes the transform, specified in Init() function. More...

Public Member Functions inherited from TVirtualFFT
	TVirtualFFT ()

virtual	~TVirtualFFT ()
	destructor More...

virtual Int_t *	GetN () const =0

virtual Int_t	GetNdim () const =0

virtual void	GetPointComplex (const Int_t *ipoint, Double_t &re, Double_t &im, Bool_t fromInput=kFALSE) const =0

virtual void	GetPointComplex (Int_t ipoint, Double_t &re, Double_t &im, Bool_t fromInput=kFALSE) const =0

virtual Double_t	GetPointReal (const Int_t *ipoint, Bool_t fromInput=kFALSE) const =0

virtual Double_t	GetPointReal (Int_t ipoint, Bool_t fromInput=kFALSE) const =0

virtual void	GetPoints (Double_t *data, Bool_t fromInput=kFALSE) const =0

virtual void	GetPointsComplex (Double_t *data, Bool_t fromInput=kFALSE) const =0

virtual void	GetPointsComplex (Double_t re, Double_t im, Bool_t fromInput=kFALSE) const =0

virtual Double_t *	GetPointsReal (Bool_t fromInput=kFALSE) const =0

virtual Int_t	GetSign () const =0

virtual Option_t *	GetTransformFlag () const =0

virtual Option_t *	GetType () const =0

virtual void	Init (Option_t flag, Int_t sign, const Int_t kind)=0

virtual Bool_t	IsInplace () const =0

virtual void	SetPoint (const Int_t *ipoint, Double_t re, Double_t im=0)=0

virtual void	SetPoint (Int_t ipoint, Double_t re, Double_t im=0)=0

virtual void	SetPointComplex (Int_t ipoint, TComplex &c)=0

virtual void	SetPoints (const Double_t *data)=0

virtual void	SetPointsComplex (const Double_t re, const Double_t im)=0

virtual void	Transform ()=0

Public Member Functions inherited from TObject
	TObject ()
	TObject constructor. More...

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

virtual	~TObject ()
	TObject destructor. 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...

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...

ULong_t	CheckedHash ()
	Check and record whether this class has a consistent Hash/RecursiveRemove setup (*) and then return the regular Hash value for this object. More...

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

virtual void	Clear (Option_t *="")

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 abstract method. More...

virtual void	Copy (TObject &object) const
	Copy this to obj. 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 selected pad for instance with: `gROOT->SetSelectedPad(gPad)`. More...

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

virtual void	Error (const char method, const char msgfmt,...) const
	Issue error message. 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 void	Fatal (const char method, const char msgfmt,...) const
	Issue fatal error message. 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 const char *	GetIconName () const
	Returns mime type name of object. More...

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

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

virtual Option_t *	GetOption () const

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

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

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

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

Bool_t	HasInconsistentHash () const
	Return true is the type of this object is known to have an inconsistent setup for Hash and RecursiveRemove (i.e. More...

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

void	InvertBit (UInt_t f)

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

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

R__ALWAYS_INLINE Bool_t	IsOnHeap () const

virtual Bool_t	IsSortable () const

R__ALWAYS_INLINE Bool_t	IsZombie () const

virtual void	ls (Option_t *option="") const
	The ls function lists the contents of a class on stdout. 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...

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

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

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

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

void *	operator new (size_t sz)

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

void *	operator new[] (size_t sz)

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

TObject &	operator= (const TObject &rhs)
	TObject assignment operator. 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 void	Print (Option_t *option="") const
	This method must be overridden when a class wants to print itself. 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...

void	ResetBit (UInt_t f)

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...

void	SetBit (UInt_t f)

void	SetBit (UInt_t f, Bool_t set)
	Set or unset the user status bits as specified in f. 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	SysError (const char method, const char msgfmt,...) const
	Issue system error message. More...

R__ALWAYS_INLINE Bool_t	TestBit (UInt_t f) const

Int_t	TestBits (UInt_t f) const

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

Protected Member Functions
UInt_t	MapFlag (Option_t *flag)
	allowed options: More...

Protected Member Functions inherited from TObject
virtual void	DoError (int level, const char location, const char fmt, va_list va) const
	Interface to ErrorHandler (protected). More...

void	MakeZombie ()

Protected Attributes
TString	fFlags

void *	fIn

Int_t *	fN

Int_t	fNdim

void *	fOut

void *	fPlan

Int_t	fSign

Int_t	fTotalSize

Additional Inherited Members
Public Types inherited from TObject
enum	{ kIsOnHeap = 0x01000000 , kNotDeleted = 0x02000000 , kZombie = 0x04000000 , kInconsistent = 0x08000000 , kBitMask = 0x00ffffff }

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

enum	EDeprecatedStatusBits { kObjInCanvas = BIT(3) }

enum	EStatusBits { kCanDelete = BIT(0) , kMustCleanup = BIT(3) , kIsReferenced = BIT(4) , kHasUUID = BIT(5) , kCannotPick = BIT(6) , kNoContextMenu = BIT(8) , kInvalidObject = BIT(13) }

Static Public Member Functions inherited from TVirtualFFT
static TVirtualFFT *	FFT (Int_t ndim, Int_t n, Option_t option)
	Returns a pointer to the FFT of requested size and type. More...

static TVirtualFFT *	GetCurrentTransform ()
	static: return current fgFFT More...

static const char *	GetDefaultFFT ()
	static: return the name of the default fft More...

static void	SetDefaultFFT (const char *name="")
	static: set name of default fft More...

static void	SetTransform (TVirtualFFT *fft)
	static: set the current transfrom to parameter More...

static TVirtualFFT *	SineCosine (Int_t ndim, Int_t n, Int_t r2rkind, Option_t *option)
	Returns a pointer to a sine or cosine transform of requested size and kind. More...

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

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

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

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

Static Protected Attributes inherited from TVirtualFFT
static TString	fgDefault = ""

static TVirtualFFT *	fgFFT = 0

#include <TFFTComplex.h>

Inheritance diagram for TFFTComplex:

[legend]

Constructor & Destructor Documentation

◆ TFFTComplex() [1/3]

TFFTComplex::TFFTComplex ( )

default

Definition at line 52 of file TFFTComplex.cxx.

◆ TFFTComplex() [2/3]

TFFTComplex::TFFTComplex	(	Int_t	n,
		Bool_t	inPlace
	)

For 1d transforms Allocates memory for the input array, and, if inPlace = kFALSE, for the output array.

Definition at line 67 of file TFFTComplex.cxx.

◆ TFFTComplex() [3/3]

TFFTComplex::TFFTComplex	(	Int_t	ndim,
		Int_t *	n,
		Bool_t	inPlace = `kFALSE`
	)

For multidim.

transforms Allocates memory for the input array, and, if inPlace = kFALSE, for the output array

Definition at line 86 of file TFFTComplex.cxx.

◆ ~TFFTComplex()

TFFTComplex::~TFFTComplex ( )

virtual

Destroys the data arrays and the plan.

However, some plan information stays around until the root session is over, and is reused if other plans of the same size are created

Definition at line 109 of file TFFTComplex.cxx.

Member Function Documentation

◆ GetN()

virtual Int_t * TFFTComplex::GetN ( ) const

inlinevirtual

Implements TVirtualFFT.

Definition at line 41 of file TFFTComplex.h.

◆ GetNdim()

virtual Int_t TFFTComplex::GetNdim ( ) const

inlinevirtual

Implements TVirtualFFT.

Definition at line 42 of file TFFTComplex.h.

◆ GetPointComplex() [1/2]

void TFFTComplex::GetPointComplex	(	const Int_t *	ipoint,
		Double_t &	re,
		Double_t &	im,
		Bool_t	fromInput = `kFALSE`
	)		const

virtual

For multidimensional transforms. Returns real and imaginary parts of the point #ipoint.

Implements TVirtualFFT.

Definition at line 203 of file TFFTComplex.cxx.

◆ GetPointComplex() [2/2]

void TFFTComplex::GetPointComplex	(	Int_t	ipoint,
		Double_t &	re,
		Double_t &	im,
		Bool_t	fromInput = `kFALSE`
	)		const

virtual

returns real and imaginary parts of the point #ipoint

Implements TVirtualFFT.

Definition at line 189 of file TFFTComplex.cxx.

◆ GetPointReal() [1/2]

virtual Double_t TFFTComplex::GetPointReal	(	const Int_t *	,
		Bool_t
	)		const

inlinevirtual

Implements TVirtualFFT.

Definition at line 51 of file TFFTComplex.h.

◆ GetPointReal() [2/2]

virtual Double_t TFFTComplex::GetPointReal	(	Int_t	,
		Bool_t
	)		const

inlinevirtual

Implements TVirtualFFT.

Definition at line 50 of file TFFTComplex.h.

◆ GetPoints()

void TFFTComplex::GetPoints	(	Double_t *	data,
		Bool_t	fromInput = `kFALSE`
	)		const

virtual

Copies the output(or input) into the argument array.

Implements TVirtualFFT.

Definition at line 171 of file TFFTComplex.cxx.

◆ GetPointsComplex() [1/2]

void TFFTComplex::GetPointsComplex	(	Double_t *	data,
		Bool_t	fromInput = `kFALSE`
	)		const

virtual

Copies the output(input) into the argument array.

Implements TVirtualFFT.

Definition at line 239 of file TFFTComplex.cxx.

◆ GetPointsComplex() [2/2]

void TFFTComplex::GetPointsComplex	(	Double_t *	re,
		Double_t *	im,
		Bool_t	fromInput = `kFALSE`
	)		const

virtual

Copies real and imaginary parts of the output (input) into the argument arrays.

Implements TVirtualFFT.

Definition at line 221 of file TFFTComplex.cxx.

◆ GetPointsReal()

virtual Double_t * TFFTComplex::GetPointsReal ( Bool_t ) const

inlinevirtual

Implements TVirtualFFT.

Definition at line 54 of file TFFTComplex.h.

◆ GetSign()

virtual Int_t TFFTComplex::GetSign ( ) const

inlinevirtual

Implements TVirtualFFT.

Definition at line 45 of file TFFTComplex.h.

◆ GetSize()

virtual Int_t TFFTComplex::GetSize ( ) const

inlinevirtual

Definition at line 43 of file TFFTComplex.h.

◆ GetTransformFlag()

virtual Option_t * TFFTComplex::GetTransformFlag ( ) const

inlinevirtual

Implements TVirtualFFT.

Definition at line 46 of file TFFTComplex.h.

◆ GetType()

virtual Option_t * TFFTComplex::GetType ( ) const

inlinevirtual

Implements TVirtualFFT.

Definition at line 44 of file TFFTComplex.h.

◆ Init()

void TFFTComplex::Init	(	Option_t *	flags,
		Int_t	sign,
		const Int_t *
	)

virtual

Creates the fftw-plan.

NOTE: input and output arrays are overwritten during initialisation, so don't set any points, before running this function!!!!!

2nd parameter: +1

Argument kind is dummy and doesn't need to be specified

Possible flag_options:

"ES" (from "estimate") - no time in preparing the transform, but probably sub-optimal performance
"M" (from "measure") - some time spend in finding the optimal way to do the transform
"P" (from "patient") - more time spend in finding the optimal way to do the transform
"EX" (from "exhaustive") - the most optimal way is found This option should be chosen depending on how many transforms of the same size and type are going to be done. Planning is only done once, for the first transform of this size and type.

Implements TVirtualFFT.

Definition at line 140 of file TFFTComplex.cxx.

◆ IsInplace()

virtual Bool_t TFFTComplex::IsInplace ( ) const

inlinevirtual

Implements TVirtualFFT.

Definition at line 47 of file TFFTComplex.h.

◆ MapFlag()

UInt_t TFFTComplex::MapFlag ( Option_t * flag )

protected

allowed options:

"ES" - FFTW_ESTIMATE
"M" - FFTW_MEASURE
"P" - FFTW_PATIENT
"EX" - FFTW_EXHAUSTIVE

Definition at line 318 of file TFFTComplex.cxx.

◆ SetPoint() [1/2]

void TFFTComplex::SetPoint	(	const Int_t *	ipoint,
		Double_t	re,
		Double_t	im = `0`
	)

virtual

For multidim. transforms. Sets real and imaginary parts of point # ipoint.

Implements TVirtualFFT.

Definition at line 266 of file TFFTComplex.cxx.

◆ SetPoint() [2/2]

void TFFTComplex::SetPoint	(	Int_t	ipoint,
		Double_t	re,
		Double_t	im = `0`
	)

virtual

sets real and imaginary parts of point # ipoint

Implements TVirtualFFT.

Definition at line 257 of file TFFTComplex.cxx.

◆ SetPointComplex()

void TFFTComplex::SetPointComplex	(	Int_t	ipoint,
		TComplex &	c
	)

virtual

Implements TVirtualFFT.

Definition at line 278 of file TFFTComplex.cxx.

◆ SetPoints()

void TFFTComplex::SetPoints ( const Double_t * data )

virtual

set all points.

the values are copied. points should be ordered as follows: [re_0, im_0, re_1, im_1, ..., re_n, im_n)

Implements TVirtualFFT.

Definition at line 288 of file TFFTComplex.cxx.

◆ SetPointsComplex()

void TFFTComplex::SetPointsComplex	(	const Double_t *	re,
		const Double_t *	im
	)

virtual

set all points. the values are copied

Implements TVirtualFFT.

Definition at line 299 of file TFFTComplex.cxx.

◆ Transform()

void TFFTComplex::Transform ( )

virtual

Computes the transform, specified in Init() function.

Implements TVirtualFFT.

Definition at line 158 of file TFFTComplex.cxx.

Member Data Documentation

◆ fFlags

TString TFFTComplex::fFlags

protected

Definition at line 29 of file TFFTComplex.h.

◆ fIn

void* TFFTComplex::fIn

protected

Definition at line 22 of file TFFTComplex.h.

◆ fN

Int_t* TFFTComplex::fN

protected

Definition at line 27 of file TFFTComplex.h.

◆ fNdim

Int_t TFFTComplex::fNdim

protected

Definition at line 25 of file TFFTComplex.h.

◆ fOut

void* TFFTComplex::fOut

protected

Definition at line 23 of file TFFTComplex.h.

◆ fPlan

void* TFFTComplex::fPlan

protected

Definition at line 24 of file TFFTComplex.h.

◆ fSign

Int_t TFFTComplex::fSign

protected

Definition at line 28 of file TFFTComplex.h.

◆ fTotalSize

Int_t TFFTComplex::fTotalSize

protected

Definition at line 26 of file TFFTComplex.h.

Libraries for TFFTComplex:

[legend]

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Constructor & Destructor Documentation

◆ TFFTComplex() [1/3]

◆ TFFTComplex() [2/3]

◆ TFFTComplex() [3/3]

◆ ~TFFTComplex()

Member Function Documentation

◆ GetN()

◆ GetNdim()

◆ GetPointComplex() [1/2]

◆ GetPointComplex() [2/2]

◆ GetPointReal() [1/2]

◆ GetPointReal() [2/2]

◆ GetPoints()

◆ GetPointsComplex() [1/2]

◆ GetPointsComplex() [2/2]

◆ GetPointsReal()

◆ GetSign()

◆ GetSize()

◆ GetTransformFlag()

◆ GetType()

◆ Init()

◆ IsInplace()

◆ MapFlag()

◆ SetPoint() [1/2]

◆ SetPoint() [2/2]

◆ SetPointComplex()

◆ SetPoints()

◆ SetPointsComplex()

◆ Transform()

Member Data Documentation

◆ fFlags

◆ fIn

◆ fN

◆ fNdim

◆ fOut

◆ fPlan

◆ fSign

◆ fTotalSize