The FORMULA class (ROOT version 5)

Example of valid expressions:

sin(x)/x
[0]*sin(x) + [1]*exp(-[2]*x)
x + y**2
x^2 + y^2
[0]*pow([1],4)
2*pi*sqrt(x/y)
gaus(0)*expo(3) + ypol3(5)*x
gausn(0)*expo(3) + ypol3(5)*x

In the last example above:

gaus(0) is a substitute for [0]*exp(-0.5*((x-[1])/[2])**2) and (0) means start numbering parameters at 0

gausn(0) is a substitute for [0]*exp(-0.5*((x-[1])/[2])**2)/(sqrt(2*pi)*[2])) and (0) means start numbering parameters at 0

expo(3) is a substitute for exp([3]+[4]*x)

pol3(5) is a substitute for par[5]+par[6]*x+par[7]*x**2+par[8]*x**3 (here Pol3 stands for Polynomial of degree 3)

TMath functions can be part of the expression, eg:

TMath::Landau(x)*sin(x)
TMath::Erf(x)

Comparisons operators are also supported (&&, ||, ==, <=, >=, !) Examples:

  sin(x*(x<0.5 || x>1))

If the result of a comparison is TRUE, the result is 1, otherwise 0.

Already predefined names can be given. For example, if the formula

TFormula old(sin(x*(x<0.5 || x>1))) one can assign a name to the formula. By default the name of the object = title = formula itself. old.SetName("old"). then, old can be reused in a new expression. TFormula new("x*old") is equivalent to: TFormula new("x*sin(x*(x<0.5 || x>1))")

Up to 4 dimensions are supported (indicated by x, y, z, t) An expression may have 0 parameters or a list of parameters indicated by the sequence [par_number]

A graph showing the logic to compile and analyze a formula is shown in TFormula::Compile and TFormula::Analyze. Once a formula has been compiled, it can be evaluated for a given set of parameters. see graph in TFormula::EvalPar.

This class is the base class for the function classes TF1,TF2 and TF3. It is also used by the ntuple selection mechanism TNtupleFormula.

In version 7 of TFormula, the usage of fOper has been changed to improve the performance of TFormula::EvalPar. Conceptually, fOper was changed from a simple array of Int_t to an array of composite values. For example a 'ylandau(5)' operation used to be encoded as 4105; it is now encoded as (klandau >> kTFOperShift) + 5 Any class inheriting from TFormula and using directly fOper (which is now a private data member), needs to be updated to take this in consideration. The member functions recommended to set and access fOper are: SetAction, GetAction, GetActionParam For more performant access to the information, see the implementation TFormula::EvalPar

CHANGING DEFAULT SETTINGS

When creating complex formula , it may be necessary to increase some default parameters. see static function TFormula::SetMaxima

WHY TFormula CANNOT ACCEPT A CLASS MEMBER FUNCTION ?

This is a frequently asked question. C++ is a strongly typed language. There is no way for TFormula (without recompiling this class) to know about all possible user defined data types. This also apply to the case of a static class function. Because TMath is a special and frequent case, TFormula is aware of all TMath functions.

Definition at line 65 of file TFormula.h.

Public Types
enum	{ kNotGlobal = BIT(10) , kNormalized = BIT(14) , kLinear = BIT(16) }

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) }

Public Member Functions
	TFormula ()
	Formula default constructor.

	TFormula (const char name, const char formula)
	Normal Formula constructor.

	TFormula (const TFormula &formula)
	Default constructor.

virtual	~TFormula ()
	Formula default destructor.

virtual void	Analyze (const char *schain, Int_t &err, Int_t offset=0)
	Analyze a sub-expression in one formula.

virtual Bool_t	AnalyzeFunction (TString &chaine, Int_t &err, Int_t offset=0)
	Check if the chain as function call.

virtual void	Clear (Option_t *option="")
	Resets the objects.

virtual Int_t	Compile (const char *expression="")
	Compile expression already stored in fTitle.

virtual void	Copy (TObject &formula) const
	Copy this formula.

virtual char *	DefinedString (Int_t code)
	Return address of string corresponding to special code.

virtual Double_t	DefinedValue (Int_t code)
	Return value corresponding to special code.

virtual Int_t	DefinedVariable (TString &variable, Int_t &action)
	Check if expression is in the list of defined variables.

virtual Double_t	Eval (Double_t x, Double_t y=0, Double_t z=0, Double_t t=0) const
	Evaluate this formula.

virtual Double_t	EvalPar (const Double_t x, const Double_t params=0)

virtual Double_t	EvalParOld (const Double_t x, const Double_t params=0)
	Evaluate this formula.

virtual TString	GetExpFormula (Option_t *option="") const
	Reconstruct the formula expression from the internal TFormula member variables.

virtual const TObject *	GetLinearPart (Int_t i)
	Return linear part.

virtual Int_t	GetNdim () const

virtual Int_t	GetNpar () const

virtual Int_t	GetNumber () const

Double_t	GetParameter (const char *name) const
	Return value of parameter named parName.

Double_t	GetParameter (Int_t ipar) const
	Return value of parameter number ipar.

virtual Double_t *	GetParameters () const

virtual void	GetParameters (Double_t *params)

virtual const char *	GetParName (Int_t ipar) const
	Return name of one parameter.

virtual Int_t	GetParNumber (const char *name) const
	Return parameter number by name.

virtual Bool_t	IsLinear () const

virtual Bool_t	IsNormalized () const

TFormula &	operator= (const TFormula &rhs)
	Operator =.

void	Optimize ()
	MI include.

virtual void	Print (Option_t *option="") const
	Dump this formula with its attributes.

virtual void	ProcessLinear (TString &replaceformula)
	If the formula is for linear fitting, change the title to normal and fill the LinearParts array.

virtual void	SetNumber (Int_t number)

virtual void	SetParameter (const char *name, Double_t parvalue)
	Initialize parameter number ipar.

virtual void	SetParameter (Int_t ipar, Double_t parvalue)
	Initialize parameter number ipar.

virtual void	SetParameters (const Double_t *params)
	Initialize array of all parameters.

virtual void	SetParameters (Double_t p0, Double_t p1, Double_t p2=0, Double_t p3=0, Double_t p4=0, Double_t p5=0, Double_t p6=0, Double_t p7=0, Double_t p8=0, Double_t p9=0, Double_t p10=0)
	Initialize up to 11 parameters All arguments except THE FIRST TWO are optional In case of a function with only one parameter, call this function with p1=0.

virtual void	SetParName (Int_t ipar, const char *name)
	Set name of parameter number ipar.

virtual void	SetParNames (const char name0="p0", const char name1="p1", const char name2="p2", const char name3="p3", const char name4="p4", const char name5="p5", const char name6="p6", const char name7="p7", const char name8="p8", const char name9="p9", const char *name10="p10")
	Set up to 11 parameter names.

void	Streamer (TBuffer &b, const TClass *onfile_class)
	Stream a class object.

void	Streamer (TBuffer &b, Int_t version, UInt_t start, UInt_t count, const TClass *onfile_class=0)
	specialized streamer function being able to read old TF1 versions as TF1Old in memory

virtual void	Update ()

Public Member Functions inherited from TNamed
	TNamed ()

	TNamed (const char name, const char title)

	TNamed (const TNamed &named)
	TNamed copy ctor.

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

virtual	~TNamed ()
	TNamed destructor.

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

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

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

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

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

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

virtual Bool_t	IsSortable () const

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

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

virtual void	SetName (const char *name)
	Set the name of the TNamed.

virtual void	SetNameTitle (const char name, const char title)
	Set all the TNamed parameters (name and title).

virtual void	SetTitle (const char *title="")
	Set the title of the TNamed.

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

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

	TObject (const TObject &object)
	TObject copy ctor.

virtual	~TObject ()
	TObject destructor.

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

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

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

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.

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

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

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

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

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

virtual TObject *	DrawClone (Option_t *option="") const
	Draw a clone of this object in the current selected pad for instance with: `gROOT->SetSelectedPad(gPad)`.

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

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

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.

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

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

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

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

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

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

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

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

virtual Option_t *	GetOption () const

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

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

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.

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

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

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

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

void	InvertBit (UInt_t f)

Bool_t	IsDestructed () const
	IsDestructed.

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

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

R__ALWAYS_INLINE Bool_t	IsOnHeap () const

R__ALWAYS_INLINE Bool_t	IsZombie () const

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).

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

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

void	operator delete (void *ptr)
	Operator delete.

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

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.

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

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

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

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

void	ResetBit (UInt_t f)

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

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

void	SetBit (UInt_t f)

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

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

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

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

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.

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

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

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

Static Public Member Functions
static void	GetMaxima (Int_t &maxop, Int_t &maxpar, Int_t &maxconst)
	static function to get the maximum value of 3 parameters -maxop : maximum number of operations -maxpar : maximum number of parameters -maxconst : maximum number of constants

static void	SetMaxima (Int_t maxop=1000, Int_t maxpar=1000, Int_t maxconst=1000)
	static function to set the maximum value of 3 parameters

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

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

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

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

Protected Types
enum	{ kEnd = 0 , kAdd = 1 , kSubstract = 2 , kMultiply = 3 , kDivide = 4 , kModulo = 5 , kcos = 10 , ksin = 11 , ktan = 12 , kacos = 13 , kasin = 14 , katan = 15 , katan2 = 16 , kfmod = 17 , kpow = 20 , ksq = 21 , ksqrt = 22 , kstrstr = 23 , kmin = 24 , kmax = 25 , klog = 30 , kexp = 31 , klog10 = 32 , kpi = 40 , kabs = 41 , ksign = 42 , kint = 43 , kSignInv = 44 , krndm = 50 , kAnd = 60 , kOr = 61 , kEqual = 62 , kNotEqual = 63 , kLess = 64 , kGreater = 65 , kLessThan = 66 , kGreaterThan = 67 , kNot = 68 , kcosh = 70 , ksinh = 71 , ktanh = 72 , kacosh = 73 , kasinh = 74 , katanh = 75 , kStringEqual = 76 , kStringNotEqual = 77 , kBitAnd = 78 , kBitOr = 79 , kLeftShift = 80 , kRightShift = 81 , kJumpIf = 82 , kJump = 83 , kexpo = 100 , kxexpo = 100 , kyexpo = 101 , kzexpo = 102 , kxyexpo = 105 , kgaus = 110 , kxgaus = 110 , kygaus = 111 , kzgaus = 112 , kxygaus = 115 , klandau = 120 , kxlandau = 120 , kylandau = 121 , kzlandau = 122 , kxylandau = 125 , kpol = 130 , kxpol = 130 , kypol = 131 , kzpol = 132 , kParameter = 140 , kConstant = 141 , kBoolOptimize = 142 , kStringConst = 143 , kVariable = 144 , kFunctionCall = 145 , kData = 146 , kUnary = 147 , kBinary = 148 , kThree = 149 , kDefinedVariable = 150 , kDefinedString = 151 , kPlusD = 152 , kPlusDD = 153 , kMultD = 154 , kMultDD = 155 , kBoolOptimizeOr = 156 , kBoolOptimizeAnd = 157 , kBoolSet = 158 , kFDM = 159 , kFD0 = 160 , kFD1 = 161 , kFD2 = 162 , kFD3 = 163 }

typedef Double_t(TObject::*	TFuncG) (const Double_t , const Double_t ) const

Protected Types inherited from TObject
enum	{ kOnlyPrepStep = BIT(3) }

Protected Member Functions
virtual Bool_t	CheckOperands (Int_t leftoperand, Int_t rightoperartion, Int_t &err)
	Check whether the operands at 'leftoper' and 'oper-1' are compatible with the operation at 'oper'.

virtual Bool_t	CheckOperands (Int_t operation, Int_t &err)
	Check whether the operand at 'oper-1' is compatible with the operation at 'oper'.

void	ClearFormula (Option_t *option="")
	Resets the objects.

virtual void	Convert (UInt_t fromVersion)

Double_t	EvalParFast (const Double_t x, const Double_t params)
	Evaluate this formula.

Double_t	EvalPrimitive (const Double_t x, const Double_t params)
	Evaluate primitive formula.

Double_t	EvalPrimitive0 (const Double_t x, const Double_t params)
	Evaluate primitive formula.

Double_t	EvalPrimitive1 (const Double_t x, const Double_t params)
	Evaluate primitive formula.

Double_t	EvalPrimitive2 (const Double_t x, const Double_t params)
	Evaluate primitive formula.

Double_t	EvalPrimitive3 (const Double_t x, const Double_t params)
	Evaluate primitive formula.

Double_t	EvalPrimitive4 (const Double_t x, const Double_t params)
	Evaluate primitive formula.

Short_t	GetAction (Int_t code) const

Short_t	GetActionOptimized (Int_t code) const

Int_t	GetActionParam (Int_t code) const

Int_t	GetActionParamOptimized (Int_t code) const

Int_t *	GetOper () const

Int_t *	GetOperOptimized () const

virtual Bool_t	IsString (Int_t oper) const
	Return true if the expression at the index 'oper' has to be treated as a string.

void	MakePrimitive (const char *expr, Int_t pos)
	MakePrimitive find TFormulaPrimitive replacement for some operands.

Int_t	PreCompile ()
	pointer to optimal function

void	SetAction (Int_t code, Int_t value, Int_t param=0)

void	SetActionOptimized (Int_t code, Int_t value, Int_t param=0)

virtual Bool_t	StringToNumber (Int_t code)
	Try to 'demote' a string into an array bytes.

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).

void	MakeZombie ()

Protected Attributes
TBits	fAlreadyFound

Double_t *	fConst

TString *	fExpr

TString *	fExprOptimized
	Number of operators after optimization.

TObjArray	fFunctions

TObjArray	fLinearParts

TString *	fNames

Int_t	fNconst

Int_t	fNdim

Int_t	fNoper

Int_t	fNOperOptimized
	cache for information

Int_t	fNpar

Int_t	fNstring

Int_t	fNumber

Int_t	fNval

TOperOffset *	fOperOffset
	[fNOperOptimized] List of operators. (See documentation for changes made at version 7)

Int_t *	fOperOptimized
	[fNOperOptimized] List of expressions

TFuncG	fOptimal
	[fNPar] predefined function

Double_t *	fParams

TFormulaPrimitive **	fPredefined
	[fNOperOptimized] Offsets of operrands

Protected Attributes inherited from TNamed
TString	fName

TString	fTitle

Private Attributes
Int_t *	fOper

#include "inc/v5/TFormula.h"

Inheritance diagram for ROOT::v5::TFormula:

[legend]

Member Typedef Documentation

◆ TFuncG

typedef Double_t(TObject::* ROOT::v5::TFormula::TFuncG) (const Double_t *, const Double_t *) const

protected

Definition at line 69 of file TFormula.h.

Member Enumeration Documentation

◆ anonymous enum

anonymous enum

protected

Enumerator
kEnd
kAdd
kSubstract
kMultiply
kDivide
kModulo
kcos
ksin
ktan
kacos
kasin
katan
katan2
kfmod
kpow
ksq
ksqrt
kstrstr
kmin
kmax
klog
kexp
klog10
kpi
kabs
ksign
kint
kSignInv
krndm
kAnd
kOr
kEqual
kNotEqual
kLess
kGreater
kLessThan
kGreaterThan
kNot
kcosh
ksinh
ktanh
kacosh
kasinh
katanh
kStringEqual
kStringNotEqual
kBitAnd
kBitOr
kLeftShift
kRightShift
kJumpIf
kJump
kexpo
kxexpo
kyexpo
kzexpo
kxyexpo
kgaus
kxgaus
kygaus
kzgaus
kxygaus
klandau
kxlandau
kylandau
kzlandau
kxylandau
kpol
kxpol
kypol
kzpol
kParameter
kConstant
kBoolOptimize
kStringConst
kVariable
kFunctionCall
kData
kUnary
kBinary
kThree
kDefinedVariable
kDefinedString
kPlusD
kPlusDD
kMultD
kMultDD
kBoolOptimizeOr
kBoolOptimizeAnd
kBoolSet
kFDM
kFD0
kFD1
kFD2
kFD3

Definition at line 135 of file TFormula.h.

◆ anonymous enum

anonymous enum

Enumerator
kNotGlobal
kNormalized
kLinear

Definition at line 211 of file TFormula.h.

Constructor & Destructor Documentation

◆ TFormula() [1/3]

TFormula::TFormula ( )

Formula default constructor.

Definition at line 136 of file TFormula_v5.cxx.

◆ TFormula() [2/3]

TFormula::TFormula	(	const char *	name,
		const char *	formula
	)

Normal Formula constructor.

Definition at line 163 of file TFormula_v5.cxx.

◆ TFormula() [3/3]

TFormula::TFormula ( const TFormula & formula )

Default constructor.

Definition at line 276 of file TFormula_v5.cxx.

◆ ~TFormula()

TFormula::~TFormula ( )

virtual

Formula default destructor.

Definition at line 314 of file TFormula_v5.cxx.

Member Function Documentation

◆ Analyze()

void TFormula::Analyze	(	const char *	schain,
		Int_t &	err,
		Int_t	offset = `0`
	)

virtual

Analyze a sub-expression in one formula.

Expressions in one formula are recursively analyzed. Result of analysis is stored in the object tables.

Table of function codes and errors

* functions :
 
  +           1                   pow          20
  -           2                   sq           21
  *           3                   sqrt         22
  /           4                   strstr       23
  %           5                   min          24
                                  max          25
                                  log          30
  cos         10                  exp          31
  sin         11                  log10        32
  tan         12
  acos        13                  abs          41
  asin        14                  sign         42
  atan        15                  int          43
  atan2       16
  fmod        17                  rndm         50
 
  cosh        70                  acosh        73
  sinh        71                  asinh        74
  tanh        72                  atanh        75
 
  expo       100                  gaus        110     gausn  (see note below)
  expo(0)    100 0                gaus(0)     110 0   gausn(0)
  expo(1)    100 1                gaus(1)     110 1   gausn(1)
  xexpo      100 x                xgaus       110 x   xgausn
  yexpo      101 x                ygaus       111 x   ygausn
  zexpo      102 x                zgaus       112 x   zgausn
  xyexpo     105 x                xygaus      115 x   xygausn
  yexpo(5)   102 5                ygaus(5)    111 5   ygausn(5)
  xyexpo(2)  105 2                xygaus(2)   115 2   xygausn(2)
 
  landau      120 x   landaun (see note below)
  landau(0)   120 0   landaun(0)
  landau(1)   120 1   landaun(1)
  xlandau     120 x   xlandaun
  ylandau     121 x   ylandaun
  zlandau     122 x   zlandaun
  xylandau    125 x   xylandaun
  ylandau(5)  121 5   ylandaun(5)
  xylandau(2) 125 2   xylandaun(2)
 
  pol0        130 x               pol1        130 1xx
  pol0(0)     130 0               pol1(0)     130 100
  pol0(1)     130 1               pol1(1)     130 101
  xpol0       130 x               xpol1       130 101
  ypol0       131 x               ypol1       131 101
  zpol0       132 x               zpol1       132 1xx
  ypol0(5)    131 5               ypol1(5)    131 105
 
  pi          40
 
  &&          60                  <            64
  ||          61                  >            65
  ==          62                  <=           66
  !=          63                  =>           67
  !           68
  ==(string)  76                  &            78
  !=(string)  77                  |            79
  <<(shift)   80                  >>(shift)    81
  ? :         82
 
* constants (kConstants) :
 
 c0  141 1      c1  141 2  etc..
 
* strings (kStringConst):
 
 sX  143 x
 
* variables (kFormulaVar) :
 
  x    144 0      y    144 1      z    144 2      t    144 3
 
* parameters :
 
  [1]        140 1
  [2]        140 2
  etc.

Special cases for normalized gaussian or landau distributions

the expression "gaus" is a substitute for

[0]*exp(-0.5*((x-[1])/[2])**2)

to obtain a standard normalized gaussian, use "gausn" instead of "gaus" the expression "gausn" is a substitute for

[0]*exp(-0.5*((x-[1])/[2])**2)/(sqrt(2*pi)*[2]))

WARNING: gaus and gausn are mutually exclusive in the same expression.

In the same way the expression "landau" is a substitute for

[0]*TMath::Landau(x,[1],[2],kFALSE)

to obtain a standard normalized landau, use "landaun" instead of "landau" the expression "landaun" is a substitute for

[0]*TMath::Landau(x,[1],[2],kTRUE)

WARNING: landau and landaun are mutually exclusive in the same expression.

Boolean optimization (kBoolOptmize) :

Those pseudo operation are used to implement lazy evaluation of && and ||. When the left hand of the expression if false (respectively true), the evaluation of the right is entirely skipped (since it would not change the value of the expression).

&& 142 11 (one operation on right) 142 21 (2 operations on right) || 142 12 (one operation on right) 142 22 (2 operations on right)

functions calls (kFunctionCall) :

f0 145 0 f1 145 1 etc..

Errors :

1   : Division By Zero
2   : Invalid Floating Point Operation
4   : Empty String
5   : invalid syntax
6   : Too many operators
7   : Too many parameters
10  : z specified but not x and y
11  : z and y specified but not x
12  : y specified but not x
13  : z and x specified but not y
20  : non integer value for parameter number
21  : atan2 requires two arguments
22  : pow requires two arguments
23  : degree of polynomial not specified
24  : Degree of polynomial must be positive
25  : Degree of polynomial must be less than 20
26  : Unknown name
27  : Too many constants in expression
28  : strstr requires two arguments
29  : interpreted or compiled function have to return a numerical type
30  : Bad numerical expression
31  : Part of the variable exist but some of it is not accessible or useable
40  : '(' is expected
41  : ')' is expected
42  : '[' is expected
43  : ']' is expected

Special functions

By default, the formula is assigned fNumber=0. However, the following formula built with simple functions are assigned fNumber:

 "gaus"      100  (or gausn)
 "xygaus"    110
 "expo"      200
 "polN"      300+N
 "landau"    400
 "xylandau"  410

Note that expressions like gaus(0), expo(1) will force fNumber=0

Warning when deriving a class from TFormula

If you overload this member function, you also HAVE TO never call the constructor:

TFormula::TFormula(const char *name,const char *expression)

name

char name[80]

Definition TGX11.cxx:110

ROOT::v5::TFormula::TFormula

TFormula()

Formula default constructor.

Definition TFormula_v5.cxx:136

and write your own constructor

MyClass::MyClass(const char *name,const char *expression) : TFormula()

ROOT::v5::TFormula

The FORMULA class (ROOT version 5)

Definition TFormula.h:65

which has to call the TFormula default constructor and whose implementation should be similar to the implementation of the normal TFormula constructor

This is necessary because the normal TFormula constructor call indirectly the virtual member functions Analyze, DefaultString, DefaultValue and DefaultVariable.

Definition at line 713 of file TFormula_v5.cxx.

◆ AnalyzeFunction()

Bool_t TFormula::AnalyzeFunction	(	TString &	chaine,
		Int_t &	err,
		Int_t	offset = `0`
	)

virtual

Check if the chain as function call.

If you overload this member function, you also HAVE TO never call the constructor:

TFormula::TFormula(const char *name,const char *expression)

and write your own constructor

MyClass::MyClass(const char *name,const char *expression) : TFormula()

which has to call the TFormula default constructor and whose implementation should be similar to the implementation of the normal TFormula constructor

This is necessary because the normal TFormula constructor call indirectly the virtual member functions Analyze, DefaultString, DefaultValue and DefaultVariable.

Definition at line 347 of file TFormula_v5.cxx.

◆ CheckOperands() [1/2]

Bool_t TFormula::CheckOperands	(	Int_t	leftoperand,
		Int_t	rightoperartion,
		Int_t &	err
	)

protectedvirtual

Check whether the operands at 'leftoper' and 'oper-1' are compatible with the operation at 'oper'.

Definition at line 2182 of file TFormula_v5.cxx.

◆ CheckOperands() [2/2]

Bool_t TFormula::CheckOperands	(	Int_t	operation,
		Int_t &	err
	)

protectedvirtual

Check whether the operand at 'oper-1' is compatible with the operation at 'oper'.

Definition at line 2168 of file TFormula_v5.cxx.

◆ Clear()

void TFormula::Clear ( Option_t * option = "" )

virtual

Resets the objects.

Resets the object to its state before compilation.

Reimplemented from TNamed.

Definition at line 2213 of file TFormula_v5.cxx.

◆ ClearFormula()

void TFormula::ClearFormula ( Option_t * option = "" )

protected

Resets the objects.

Resets the object to its state before compilation.

Definition at line 2223 of file TFormula_v5.cxx.

◆ Compile()

Int_t TFormula::Compile ( const char * expression = "" )

virtual

Compile expression already stored in fTitle.

Loop on all subexpressions of formula stored in fTitle

If you overload this member function, you also HAVE TO never call the constructor:

TFormula::TFormula(const char *name,const char *expression)

and write your own constructor

MyClass::MyClass(const char *name,const char *expression) : TFormula()

which has to call the TFormula default constructor and whose implementation should be similar to the implementation of the normal TFormula constructor

This is necessary because the normal TFormula constructor call indirectly the virtual member functions Analyze, DefaultString, DefaultValue and DefaultVariable.

Definition at line 2292 of file TFormula_v5.cxx.

◆ Convert()

void TFormula::Convert ( UInt_t fromVersion )

protectedvirtual

Reimplemented in TTreeFormula.

Definition at line 3564 of file TFormula_v5.cxx.

◆ Copy()

void TFormula::Copy ( TObject & formula ) const

virtual

Copy this formula.

Reimplemented from TNamed.

Definition at line 2461 of file TFormula_v5.cxx.

◆ DefinedString()

char * TFormula::DefinedString ( Int_t code )

virtual

Return address of string corresponding to special code.

This member function is inactive in the TFormula class. It may be redefined in derived classes.

If you overload this member function, you also HAVE TO never call the constructor:

TFormula::TFormula(const char *name,const char *expression)

and write your own constructor

MyClass::MyClass(const char *name,const char *expression) : TFormula()

which has to call the TFormula default constructor and whose implementation should be similar to the implementation of the normal TFormula constructor

This is necessary because the normal TFormula constructor call indirectly the virtual member functions Analyze, DefaultString, DefaultValue and DefaultVariable.

Definition at line 2555 of file TFormula_v5.cxx.

◆ DefinedValue()

Double_t TFormula::DefinedValue ( Int_t code )

virtual

Return value corresponding to special code.

This member function is inactive in the TFormula class. It may be redefined in derived classes.

If you overload this member function, you also HAVE TO never call the constructor:

TFormula::TFormula(const char *name,const char *expression)

and write your own constructor

MyClass::MyClass(const char *name,const char *expression) : TFormula()

which has to call the TFormula default constructor and whose implementation should be similar to the implementation of the normal TFormula constructor

This is necessary because the normal TFormula constructor call indirectly the virtual member functions Analyze, DefaultString, DefaultValue and DefaultVariable.

Definition at line 2586 of file TFormula_v5.cxx.

◆ DefinedVariable()

Int_t TFormula::DefinedVariable	(	TString &	chaine,
		Int_t &	action
	)

virtual

Check if expression is in the list of defined variables.

This member function can be overloaded in derived classes

If you overload this member function, you also HAVE TO never call the constructor:

TFormula::TFormula(const char *name,const char *expression)

and write your own constructor

MyClass::MyClass(const char *name,const char *expression) : TFormula()

which has to call the TFormula default constructor and whose implementation should be similar to the implementation of the normal TFormula constructor

This is necessary because the normal TFormula constructor call indirectly the virtual member functions Analyze, DefaultString, DefaultValue and DefaultVariable.

The expected returns values are

-2 : the name has been recognized but won't be usable
-1 : the name has not been recognized
>=0 : the name has been recognized, return the action parameter.

Reimplemented in TTreeFormula.

Definition at line 2621 of file TFormula_v5.cxx.

◆ Eval()

Double_t TFormula::Eval	(	Double_t	x,
		Double_t	y = `0`,
		Double_t	z = `0`,
		Double_t	t = `0`
	)		const

virtual

Evaluate this formula.

The current value of variables x,y,z,t is passed through x, y, z and t. The parameters used will be the ones in the array params if params is given otherwise parameters will be taken from the stored data members fParams

Definition at line 2668 of file TFormula_v5.cxx.

◆ EvalPar()

virtual Double_t ROOT::v5::TFormula::EvalPar	(	const Double_t *	x,
		const Double_t *	params = `0`
	)

inlinevirtual

Definition at line 235 of file TFormula.h.

◆ EvalParFast()

Double_t TFormula::EvalParFast	(	const Double_t *	x,
		const Double_t *	uparams
	)

protected

Evaluate this formula.

The current value of variables x,y,z,t is passed through the pointer x. The parameters used will be the ones in the array params if params is given otherwise parameters will be taken from the stored data members fParams

Definition at line 4189 of file TFormula_v5.cxx.

◆ EvalParOld()

Double_t TFormula::EvalParOld	(	const Double_t *	x,
		const Double_t *	uparams = `0`
	)

virtual

Evaluate this formula.

The current value of variables x,y,z,t is passed through the pointer x. The parameters used will be the ones in the array params if params is given otherwise parameters will be taken from the stored data members fParams

Definition at line 2687 of file TFormula_v5.cxx.

◆ EvalPrimitive()

Double_t TFormula::EvalPrimitive	(	const Double_t *	x,
		const Double_t *	params
	)

protected

Evaluate primitive formula.

Definition at line 4114 of file TFormula_v5.cxx.

◆ EvalPrimitive0()

Double_t TFormula::EvalPrimitive0	(	const Double_t *	x,
		const Double_t *	params
	)

protected

Evaluate primitive formula.

Definition at line 4135 of file TFormula_v5.cxx.

◆ EvalPrimitive1()

Double_t TFormula::EvalPrimitive1	(	const Double_t *	x,
		const Double_t *	params
	)

protected

Evaluate primitive formula.

Definition at line 4144 of file TFormula_v5.cxx.

◆ EvalPrimitive2()

Double_t TFormula::EvalPrimitive2	(	const Double_t *	x,
		const Double_t *	params
	)

protected

Evaluate primitive formula.

Definition at line 4153 of file TFormula_v5.cxx.

◆ EvalPrimitive3()

Double_t TFormula::EvalPrimitive3	(	const Double_t *	x,
		const Double_t *	params
	)

protected

Evaluate primitive formula.

Definition at line 4163 of file TFormula_v5.cxx.

◆ EvalPrimitive4()

Double_t TFormula::EvalPrimitive4	(	const Double_t *	x,
		const Double_t *	params
	)

protected

Evaluate primitive formula.

Definition at line 4173 of file TFormula_v5.cxx.

◆ GetAction()

Short_t ROOT::v5::TFormula::GetAction ( Int_t code ) const

inlineprotected

Definition at line 104 of file TFormula.h.

◆ GetActionOptimized()

Short_t ROOT::v5::TFormula::GetActionOptimized ( Int_t code ) const

inlineprotected

Definition at line 112 of file TFormula.h.

◆ GetActionParam()

Int_t ROOT::v5::TFormula::GetActionParam ( Int_t code ) const

inlineprotected

Definition at line 105 of file TFormula.h.

◆ GetActionParamOptimized()

Int_t ROOT::v5::TFormula::GetActionParamOptimized ( Int_t code ) const

inlineprotected

Definition at line 113 of file TFormula.h.

◆ GetExpFormula()

TString TFormula::GetExpFormula ( Option_t * option = "" ) const

virtual

Reconstruct the formula expression from the internal TFormula member variables.

This function uses the internal member variables of TFormula to construct the mathematical expression associated with the TFormula instance. This function can be used to get an expanded version of the expression originally assigned to the TFormula instance, i.e. that the string returned by GetExpFormula() doesn't depend on other TFormula object names.

if option contains "p" the returned string will contain the formula expression with symbolic parameters, eg [0] replaced by the actual value of the parameter. Example: if expression in formula is: "[0]*(x>-[1])+[2]*exp(-[3]*x)" and parameters are 3.25,-4.01,4.44,-0.04, GetExpFormula("p") will return: "(3.25*(x>+4.01))+(4.44*exp(+0.04*x))"

Definition at line 3022 of file TFormula_v5.cxx.

◆ GetLinearPart()

const TObject * TFormula::GetLinearPart ( Int_t i )

virtual

Return linear part.

Definition at line 3212 of file TFormula_v5.cxx.

◆ GetMaxima()

void TFormula::GetMaxima	(	Int_t &	maxop,
		Int_t &	maxpar,
		Int_t &	maxconst
	)

static

static function to get the maximum value of 3 parameters -maxop : maximum number of operations -maxpar : maximum number of parameters -maxconst : maximum number of constants

Definition at line 4540 of file TFormula_v5.cxx.

◆ GetNdim()

virtual Int_t ROOT::v5::TFormula::GetNdim ( ) const

inlinevirtual

Definition at line 237 of file TFormula.h.

◆ GetNpar()

virtual Int_t ROOT::v5::TFormula::GetNpar ( ) const

inlinevirtual

Definition at line 238 of file TFormula.h.

◆ GetNumber()

virtual Int_t ROOT::v5::TFormula::GetNumber ( ) const

inlinevirtual

Definition at line 239 of file TFormula.h.

◆ GetOper()

Int_t * ROOT::v5::TFormula::GetOper ( ) const

inlineprotected

Definition at line 103 of file TFormula.h.

◆ GetOperOptimized()

Int_t * ROOT::v5::TFormula::GetOperOptimized ( ) const

inlineprotected

Definition at line 111 of file TFormula.h.

◆ GetParameter() [1/2]

Double_t TFormula::GetParameter ( const char * name ) const

Return value of parameter named parName.

Definition at line 3231 of file TFormula_v5.cxx.

◆ GetParameter() [2/2]

Double_t TFormula::GetParameter ( Int_t ipar ) const

Return value of parameter number ipar.

Definition at line 3222 of file TFormula_v5.cxx.

◆ GetParameters() [1/2]

virtual Double_t * ROOT::v5::TFormula::GetParameters ( ) const

inlinevirtual

Definition at line 243 of file TFormula.h.

◆ GetParameters() [2/2]

virtual void ROOT::v5::TFormula::GetParameters ( Double_t * params )

inlinevirtual

Definition at line 244 of file TFormula.h.

◆ GetParName()

const char * TFormula::GetParName ( Int_t ipar ) const

virtual

Return name of one parameter.

Definition at line 3245 of file TFormula_v5.cxx.

◆ GetParNumber()

Int_t TFormula::GetParNumber ( const char * name ) const

virtual

Return parameter number by name.

Definition at line 3255 of file TFormula_v5.cxx.

◆ IsLinear()

virtual Bool_t ROOT::v5::TFormula::IsLinear ( ) const

inlinevirtual

Definition at line 247 of file TFormula.h.

◆ IsNormalized()

virtual Bool_t ROOT::v5::TFormula::IsNormalized ( ) const

inlinevirtual

Definition at line 248 of file TFormula.h.

◆ IsString()

Bool_t TFormula::IsString ( Int_t oper ) const

protectedvirtual

Return true if the expression at the index 'oper' has to be treated as a string.

Reimplemented in TTreeFormula.

Definition at line 3269 of file TFormula_v5.cxx.

◆ MakePrimitive()

void TFormula::MakePrimitive	(	const char *	expr,
		Int_t	pos
	)

protected

MakePrimitive find TFormulaPrimitive replacement for some operands.

Definition at line 3746 of file TFormula_v5.cxx.

◆ operator=()

TFormula & TFormula::operator= ( const TFormula & rhs )

Operator =.

Definition at line 303 of file TFormula_v5.cxx.

◆ Optimize()

void TFormula::Optimize ( )

MI include.

Optimize formula

Minimize the number of operands
1. several operands are glued together
2. some primitive functions glued together - exemp. (x+y) => PlusXY(x,y)
3. maximize number of standard calls minimizing number of jumps in Eval cases
4. variables, parameters and constants are mapped - using fOperOfssets0 Eval procedure use direct acces to data (only one corresponding case statement in eval procedure)
  pdata[operand={Var,Par,Const}][offset]
  
  pdata[fOperOffsets0[i]][fOperOffset1[i+1]]
The fastest evaluation function is chosen at the end
1. fOptimal := pointer to the fastest function for given evaluation string
  switch(GetActionOptimized(0)){
  
  case kData : {fOptimal= (TFormulaPrimitive::TFuncG)&TFormula::EvalPrimitive0; break;}
  
  case kUnary : {fOptimal= (TFormulaPrimitive::TFuncG)&TFormula::EvalPrimitive1; break;}
  
  case kBinary : {fOptimal= (TFormulaPrimitive::TFuncG)&TFormula::EvalPrimitive2; break;}
  
  case kThree : {fOptimal= (TFormulaPrimitive::TFuncG)&TFormula::EvalPrimitive3; break;}
  
  case kFDM : {fOptimal= (TFormulaPrimitive::TFuncG)&TFormula::EvalPrimitive4; break;}
  
  }
  
  ROOT::v5::TFormulaPrimitive::TFuncG
  Double_t(TObject::* TFuncG)(const Double_t *, const Double_t *) const
  Definition TFormulaPrimitive.h:46
  
  ROOT::v5::TFormula::EvalPrimitive1
  Double_t EvalPrimitive1(const Double_t *x, const Double_t *params)
  Evaluate primitive formula.
  Definition TFormula_v5.cxx:4144
  
  ROOT::v5::TFormula::EvalPrimitive0
  Double_t EvalPrimitive0(const Double_t *x, const Double_t *params)
  Evaluate primitive formula.
  Definition TFormula_v5.cxx:4135
  
  ROOT::v5::TFormula::EvalPrimitive2
  Double_t EvalPrimitive2(const Double_t *x, const Double_t *params)
  Evaluate primitive formula.
  Definition TFormula_v5.cxx:4153
  
  ROOT::v5::TFormula::kData
  @ kData
  Definition TFormula.h:188
  
  ROOT::v5::TFormula::kThree
  @ kThree
  Definition TFormula.h:191
  
  ROOT::v5::TFormula::kFDM
  @ kFDM
  Definition TFormula.h:202
  
  ROOT::v5::TFormula::kBinary
  @ kBinary
  Definition TFormula.h:190
  
  ROOT::v5::TFormula::kUnary
  @ kUnary
  Definition TFormula.h:189
  
  ROOT::v5::TFormula::GetActionOptimized
  Short_t GetActionOptimized(Int_t code) const
  Definition TFormula.h:112
  
  ROOT::v5::TFormula::EvalPrimitive3
  Double_t EvalPrimitive3(const Double_t *x, const Double_t *params)
  Evaluate primitive formula.
  Definition TFormula_v5.cxx:4163
  
  ROOT::v5::TFormula::fOptimal
  TFuncG fOptimal
  [fNPar] predefined function
  Definition TFormula.h:96
  
  ROOT::v5::TFormula::EvalPrimitive4
  Double_t EvalPrimitive4(const Double_t *x, const Double_t *params)
  Evaluate primitive formula.
  Definition TFormula_v5.cxx:4173
2. ex.
  - fOptimal = EvalPrimitive0 - if it return only variable, constant or parameter
  - = ::EvalParameter1 - if only one unary operation
  - = EvalPrimitive2 - if only one binary operation

Definition at line 3818 of file TFormula_v5.cxx.

◆ PreCompile()

Int_t TFormula::PreCompile ( )

protected

pointer to optimal function

Pre compile function.

Definition at line 4481 of file TFormula_v5.cxx.

◆ Print()

void TFormula::Print ( Option_t * option = "" ) const

virtual

Dump this formula with its attributes.

Reimplemented from TNamed.

Definition at line 3277 of file TFormula_v5.cxx.

◆ ProcessLinear()

void TFormula::ProcessLinear ( TString & replaceformula )

virtual

If the formula is for linear fitting, change the title to normal and fill the LinearParts array.

Definition at line 3306 of file TFormula_v5.cxx.

◆ SetAction()

void ROOT::v5::TFormula::SetAction	(	Int_t	code,
		Int_t	value,
		Int_t	param = `0`
	)

inlineprotected

Definition at line 107 of file TFormula.h.

◆ SetActionOptimized()

void ROOT::v5::TFormula::SetActionOptimized	(	Int_t	code,
		Int_t	value,
		Int_t	param = `0`
	)

inlineprotected

Definition at line 115 of file TFormula.h.

◆ SetMaxima()

void TFormula::SetMaxima	(	Int_t	maxop = `1000`,
		Int_t	maxpar = `1000`,
		Int_t	maxconst = `1000`
	)

static

static function to set the maximum value of 3 parameters

maxop : maximum number of operations
maxpar : maximum number of parameters
maxconst : maximum number of constants

None of these parameters cannot be less than 10 (default is 1000) call this function to increase one or all maxima when processing very complex formula, eg TFormula::SetMaxima(100000,1000,1000000); If you process many functions with a small number of operations/parameters you may gain some memory and performance by decreasing these values.

Definition at line 4527 of file TFormula_v5.cxx.

◆ SetNumber()

virtual void ROOT::v5::TFormula::SetNumber ( Int_t number )

inlinevirtual

Definition at line 251 of file TFormula.h.

◆ SetParameter() [1/2]

void TFormula::SetParameter	(	const char *	name,
		Double_t	parvalue
	)

virtual

Initialize parameter number ipar.

Definition at line 3375 of file TFormula_v5.cxx.

◆ SetParameter() [2/2]

void TFormula::SetParameter	(	Int_t	ipar,
		Double_t	parvalue
	)

virtual

Initialize parameter number ipar.

Definition at line 3386 of file TFormula_v5.cxx.

◆ SetParameters() [1/2]

void TFormula::SetParameters ( const Double_t * params )

virtual

Initialize array of all parameters.

See also the next function with the same name.

Definition at line 3397 of file TFormula_v5.cxx.

◆ SetParameters() [2/2]

void TFormula::SetParameters	(	Double_t	p0,
		Double_t	p1,
		Double_t	p2 = `0`,
		Double_t	p3 = `0`,
		Double_t	p4 = `0`,
		Double_t	p5 = `0`,
		Double_t	p6 = `0`,
		Double_t	p7 = `0`,
		Double_t	p8 = `0`,
		Double_t	p9 = `0`,
		Double_t	p10 = `0`
	)

virtual

Initialize up to 11 parameters All arguments except THE FIRST TWO are optional In case of a function with only one parameter, call this function with p1=0.

Minimum two arguments are required to differentiate this function from the SetParameters(cont Double_t *params)

Definition at line 3412 of file TFormula_v5.cxx.

◆ SetParName()

void TFormula::SetParName	(	Int_t	ipar,
		const char *	name
	)

virtual

Set name of parameter number ipar.

Definition at line 3432 of file TFormula_v5.cxx.

◆ SetParNames()

void TFormula::SetParNames	(	const char *	name0 = `"p0"`,
		const char *	name1 = `"p1"`,
		const char *	name2 = `"p2"`,
		const char *	name3 = `"p3"`,
		const char *	name4 = `"p4"`,
		const char *	name5 = `"p5"`,
		const char *	name6 = `"p6"`,
		const char *	name7 = `"p7"`,
		const char *	name8 = `"p8"`,
		const char *	name9 = `"p9"`,
		const char *	name10 = `"p10"`
	)

virtual

Set up to 11 parameter names.

Definition at line 3441 of file TFormula_v5.cxx.

◆ Streamer() [1/2]

void TFormula::Streamer	(	TBuffer &	b,
		const TClass *	onfile_class
	)

Stream a class object.

Definition at line 3460 of file TFormula_v5.cxx.

◆ Streamer() [2/2]

void TFormula::Streamer	(	TBuffer &	b,
		Int_t	version,
		UInt_t	start,
		UInt_t	count,
		const TClass *	onfile_class = `0`
	)

specialized streamer function being able to read old TF1 versions as TF1Old in memory

Definition at line 3498 of file TFormula_v5.cxx.

◆ StringToNumber()

Bool_t TFormula::StringToNumber ( Int_t code )

protectedvirtual

Try to 'demote' a string into an array bytes.

If this is not possible, return false.

Reimplemented in TTreeFormula.

Definition at line 2202 of file TFormula_v5.cxx.

◆ Update()

virtual void ROOT::v5::TFormula::Update ( )

inlinevirtual

Definition at line 263 of file TFormula.h.

Member Data Documentation

◆ fAlreadyFound

TBits ROOT::v5::TFormula::fAlreadyFound

protected

Definition at line 88 of file TFormula.h.

◆ fConst

Double_t* ROOT::v5::TFormula::fConst

protected

Definition at line 82 of file TFormula.h.

◆ fExpr

TString* ROOT::v5::TFormula::fExpr

protected

Definition at line 78 of file TFormula.h.

◆ fExprOptimized

TString* ROOT::v5::TFormula::fExprOptimized

protected

Number of operators after optimization.

Definition at line 92 of file TFormula.h.

◆ fFunctions

TObjArray ROOT::v5::TFormula::fFunctions

protected

Definition at line 85 of file TFormula.h.

◆ fLinearParts

TObjArray ROOT::v5::TFormula::fLinearParts

protected

Definition at line 86 of file TFormula.h.

◆ fNames

TString* ROOT::v5::TFormula::fNames

protected

Definition at line 84 of file TFormula.h.

◆ fNconst

Int_t ROOT::v5::TFormula::fNconst

protected

Definition at line 74 of file TFormula.h.

◆ fNdim

Int_t ROOT::v5::TFormula::fNdim

protected

Definition at line 71 of file TFormula.h.

◆ fNoper

Int_t ROOT::v5::TFormula::fNoper

protected

Definition at line 73 of file TFormula.h.

◆ fNOperOptimized

Int_t ROOT::v5::TFormula::fNOperOptimized

protected

cache for information

Definition at line 91 of file TFormula.h.

◆ fNpar

Int_t ROOT::v5::TFormula::fNpar

protected

Definition at line 72 of file TFormula.h.

◆ fNstring

Int_t ROOT::v5::TFormula::fNstring

protected

Definition at line 77 of file TFormula.h.

◆ fNumber

Int_t ROOT::v5::TFormula::fNumber

protected

Definition at line 75 of file TFormula.h.

◆ fNval

Int_t ROOT::v5::TFormula::fNval

protected

Definition at line 76 of file TFormula.h.

◆ fOper

Int_t* ROOT::v5::TFormula::fOper

private

Definition at line 80 of file TFormula.h.

◆ fOperOffset

TOperOffset* ROOT::v5::TFormula::fOperOffset

protected

[fNOperOptimized] List of operators. (See documentation for changes made at version 7)

Definition at line 94 of file TFormula.h.

◆ fOperOptimized

Int_t* ROOT::v5::TFormula::fOperOptimized

protected

[fNOperOptimized] List of expressions

Definition at line 93 of file TFormula.h.

◆ fOptimal

TFuncG ROOT::v5::TFormula::fOptimal

protected

[fNPar] predefined function

Definition at line 96 of file TFormula.h.

◆ fParams

Double_t* ROOT::v5::TFormula::fParams

protected

Definition at line 83 of file TFormula.h.

◆ fPredefined

TFormulaPrimitive** ROOT::v5::TFormula::fPredefined

protected

[fNOperOptimized] Offsets of operrands

Definition at line 95 of file TFormula.h.

Libraries for ROOT::v5::TFormula:

[legend]

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

hist/hist/inc/v5/TFormula.h
hist/hist/src/TFormula_v5.cxx

CHANGING DEFAULT SETTINGS

WHY TFormula CANNOT ACCEPT A CLASS MEMBER FUNCTION ?

Public Types

Public Member Functions

Static Public Member Functions

Protected Types

Protected Member Functions

Protected Attributes

Private Attributes

Member Typedef Documentation

◆ TFuncG

Member Enumeration Documentation

◆ anonymous enum

◆ anonymous enum

Constructor & Destructor Documentation

◆ TFormula() [1/3]

◆ TFormula() [2/3]

◆ TFormula() [3/3]

◆ ~TFormula()

Member Function Documentation

◆ Analyze()

Table of function codes and errors

Special cases for normalized gaussian or landau distributions

Boolean optimization (kBoolOptmize) :

Errors :

Special functions

Warning when deriving a class from TFormula

◆ AnalyzeFunction()

◆ CheckOperands() [1/2]

◆ CheckOperands() [2/2]

◆ Clear()

◆ ClearFormula()

◆ Compile()

◆ Convert()

◆ Copy()

◆ DefinedString()

◆ DefinedValue()

◆ DefinedVariable()

◆ Eval()

◆ EvalPar()

◆ EvalParFast()

◆ EvalParOld()

◆ EvalPrimitive()

◆ EvalPrimitive0()

◆ EvalPrimitive1()

◆ EvalPrimitive2()

◆ EvalPrimitive3()

◆ EvalPrimitive4()

◆ GetAction()

◆ GetActionOptimized()

◆ GetActionParam()

◆ GetActionParamOptimized()

◆ GetExpFormula()

◆ GetLinearPart()

◆ GetMaxima()

◆ GetNdim()

◆ GetNpar()

◆ GetNumber()

◆ GetOper()

◆ GetOperOptimized()

◆ GetParameter() [1/2]

◆ GetParameter() [2/2]

◆ GetParameters() [1/2]

◆ GetParameters() [2/2]

◆ GetParName()

◆ GetParNumber()

◆ IsLinear()

◆ IsNormalized()

◆ IsString()

◆ MakePrimitive()

◆ operator=()

◆ Optimize()

◆ PreCompile()

◆ Print()

◆ ProcessLinear()

◆ SetAction()

◆ SetActionOptimized()

◆ SetMaxima()

◆ SetNumber()

◆ SetParameter() [1/2]