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Reference Guide
RooFormula Class Reference

RooFormula internally uses ROOT's TFormula to compute user-defined expressions of RooAbsArgs.

The string expression can be any valid TFormula expression referring to the listed servers either by name or by their ordinal list position. These three are forms equivalent:

RooFormula("formula", "x*y", RooArgList(x,y)) or
RooFormula("formula", "@0*@1", RooArgList(x,y))
RooFormula("formula", "x[0]*x[1]", RooArgList(x,y))

Note that x[i] is an expression reserved for TFormula. If a variable with the name x is given, the RooFormula interprets x as a variable name, but x[i] as an index in the list of variables.

Category expressions

State information of RooAbsCategories can be accessed using the '::' operator, i.e.*, tagCat::Kaon will resolve to the numerical value of the Kaon state of the RooAbsCategory object named tagCat.

A formula to switch between lepton categories could look like this:

RooFormula("formulaWithCat",
"x * (leptonMulti == leptonMulti::one) + y * (leptonMulti == leptonMulti::two)",
RooArgList(x, y, leptonMulti));

Debugging a formula that won't compile

When the formula is preprocessed, RooFit can print information in the debug stream. These can be retrieved by activating the RooFit::MsgLevel RooFit::DEBUG and the RooFit::MsgTopic RooFit::InputArguments. Check the tutorial rf506_msgservice.C for details.

Definition at line 34 of file RooFormula.h.

Public Member Functions

 RooFormula ()
 Default constructor coverity[UNINIT_CTOR]. More...
 
 RooFormula (const char *name, const char *formula, const RooArgList &varList, bool checkVariables=true)
 Construct a new formula. More...
 
 RooFormula (const RooFormula &other, const char *name=0)
 Copy constructor. More...
 
RooArgSet actualDependents () const
 Return list of arguments which are used in the formula. More...
 
Bool_t changeDependents (const RooAbsCollection &newDeps, Bool_t mustReplaceAll, Bool_t nameChange)
 Change used variables to those with the same name in given list. More...
 
virtual TObjectClone (const char *newName=nullptr) const
 Make a clone of an object using the Streamer facility. More...
 
void dump () const
 DEBUG: Dump state information. More...
 
Double_t eval (const RooArgSet *nset=0) const
 Evalute all parameters/observables, and then evaluate formula. More...
 
RooSpan< doubleevaluateSpan (const RooAbsReal *dataOwner, BatchHelpers::RunContext &inputData, const RooArgSet *nset=nullptr) const
 
std::string formulaString () const
 
RooAbsArggetParameter (const char *name) const
 Return pointer to the parameter with given name. More...
 
RooAbsArggetParameter (Int_t index) const
 Return pointer to parameter at given index. More...
 
Bool_t ok () const
 
virtual void Print (Option_t *options=0) const
 Print TNamed name and title. More...
 
virtual void printArgs (std::ostream &os) const
 Print arguments of formula, i.e. dependents that are actually used. More...
 
virtual void printClassName (std::ostream &os) const
 Print class name of formula. More...
 
void printMultiline (std::ostream &os, Int_t contents, Bool_t verbose=kFALSE, TString indent="") const
 Printing interface. More...
 
virtual void printName (std::ostream &os) const
 Print name of formula. More...
 
virtual void printTitle (std::ostream &os) const
 Print title of formula. More...
 
virtual void printValue (std::ostream &os) const
 Print value of formula. More...
 
Bool_t reCompile (const char *newFormula)
 Recompile formula with new expression. More...
 
- Public Member Functions inherited from TNamed
 TNamed ()
 
 TNamed (const char *name, const char *title)
 
 TNamed (const TNamed &named)
 TNamed copy ctor. More...
 
 TNamed (const TString &name, const TString &title)
 
virtual ~TNamed ()
 TNamed destructor. More...
 
virtual void Clear (Option_t *option="")
 Set name and title to empty strings (""). 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 ls (Option_t *option="") const
 List TNamed name and title. More...
 
TNamedoperator= (const TNamed &rhs)
 TNamed assignment operator. More...
 
virtual void SetName (const char *name)
 Set the name of the TNamed. More...
 
virtual void SetNameTitle (const char *name, const char *title)
 Set all the TNamed parameters (name and title). More...
 
virtual void SetTitle (const char *title="")
 Set the title of the TNamed. More...
 
virtual Int_t Sizeof () const
 Return size of the TNamed part of the TObject. More...
 
- 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 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 TObjectDrawClone (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 TObjectFindObject (const char *name) const
 Must be redefined in derived classes. More...
 
virtual TObjectFindObject (const TObject *obj) const
 Must be redefined in derived classes. More...
 
virtual Option_tGetDrawOption () 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 char * GetObjectInfo (Int_t px, Int_t py) const
 Returns string containing info about the object at position (px,py). More...
 
virtual Option_tGetOption () const
 
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...
 
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
 
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). 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...
 
voidoperator new (size_t sz)
 
voidoperator new (size_t sz, void *vp)
 
voidoperator new[] (size_t sz)
 
voidoperator new[] (size_t sz, void *vp)
 
TObjectoperator= (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 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...
 
- Public Member Functions inherited from RooPrintable
 RooPrintable ()
 
virtual ~RooPrintable ()
 
virtual Int_t defaultPrintContents (Option_t *opt) const
 Default choice of contents to be printed (name and value) More...
 
virtual StyleOption defaultPrintStyle (Option_t *opt) const
 
virtual void printAddress (std::ostream &os) const
 Print class name of object. More...
 
virtual void printExtras (std::ostream &os) const
 Interface to print extras of object. More...
 
virtual void printStream (std::ostream &os, Int_t contents, StyleOption style, TString indent="") const
 Print description of object on ostream, printing contents set by contents integer, which is interpreted as an OR of 'enum ContentsOptions' values and in the style given by 'enum StyleOption'. More...
 
virtual void printTree (std::ostream &os, TString indent="") const
 Interface for tree structure printing of object. More...
 

Private Member Functions

void installFormulaOrThrow (const std::string &formulaa)
 Check that the formula compiles, and also fulfills the assumptions. More...
 
RooFormulaoperator= (const RooFormula &other)
 
std::string processFormula (std::string origFormula) const
 Process given formula by replacing all ordinal and name references by x[i], where i matches the position of the argument in _origList. More...
 
std::string reconstructFormula (std::string internalRepr) const
 From the internal representation, construct a formula by replacing all index place holders with the names of the variables that are being used to evaluate it. More...
 
RooArgList usedVariables () const
 Analyse internal formula to find out which variables are actually in use. More...
 

Private Attributes

std::vector< bool_isCategory
 Original list of dependents. More...
 
RooArgList _origList
 
std::unique_ptr< TFormula_tFormula
 Whether an element of the _origList is a category. More...
 

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)
}
 
- Public Types inherited from RooPrintable
enum  ContentsOption {
  kName =1, kClassName =2, kValue =4, kArgs =8,
  kExtras =16, kAddress =32, kTitle =64, kCollectionHeader =128
}
 
enum  StyleOption {
  kInline =1, kSingleLine =2, kStandard =3, kVerbose =4,
  kTreeStructure =5
}
 
- 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 Public Member Functions inherited from RooPrintable
static std::ostream & defaultPrintStream (std::ostream *os=0)
 Return a reference to the current default stream to use in Print(). More...
 
static void nameFieldLength (Int_t newLen)
 Set length of field reserved from printing name of RooAbsArgs in multi-line collection printing to given amount. 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 inherited from TNamed
TString fName
 
TString fTitle
 
- Static Protected Attributes inherited from RooPrintable
static Int_t _nameLength
 

#include <RooFormula.h>

Inheritance diagram for RooFormula:
[legend]

Constructor & Destructor Documentation

◆ RooFormula() [1/3]

RooFormula::RooFormula ( )

Default constructor coverity[UNINIT_CTOR].

Definition at line 99 of file RooFormula.cxx.

◆ RooFormula() [2/3]

RooFormula::RooFormula ( const char *  name,
const char *  formula,
const RooArgList varList,
bool  checkVariables = true 
)

Construct a new formula.

Parameters
[in]nameName of the formula.
[in]formulaFormula to be evaluated. Parameters/observables are identified by name or ordinal position in varList.
[in]varListList of variables to be passed to the formula.
[in]checkVariablesCheck that the variables being passed in the varList are used in the formula expression.

Definition at line 112 of file RooFormula.cxx.

◆ RooFormula() [3/3]

RooFormula::RooFormula ( const RooFormula other,
const char *  name = 0 
)

Copy constructor.

Definition at line 133 of file RooFormula.cxx.

Member Function Documentation

◆ actualDependents()

RooArgSet RooFormula::actualDependents ( ) const
inline

Return list of arguments which are used in the formula.

Definition at line 44 of file RooFormula.h.

◆ changeDependents()

Bool_t RooFormula::changeDependents ( const RooAbsCollection newDeps,
Bool_t  mustReplaceAll,
Bool_t  nameChange 
)

Change used variables to those with the same name in given list.

Parameters
[in]newDepsNew dependents to replace the old ones.
[in]mustReplaceAllWill yield an error if one dependent does not have a replacement.
[in]nameChangePassed down to RooAbsArg::findNewServer(const RooAbsCollection&, Bool_t) const.

Definition at line 308 of file RooFormula.cxx.

◆ Clone()

virtual TObject* RooFormula::Clone ( const char *  newname = nullptr) const
inlinevirtual

Make a clone of an object using the Streamer facility.

If newname is specified, this will be the name of the new object.

Reimplemented from TNamed.

Definition at line 40 of file RooFormula.h.

◆ dump()

void RooFormula::dump ( ) const

DEBUG: Dump state information.

Definition at line 297 of file RooFormula.cxx.

◆ eval()

Double_t RooFormula::eval ( const RooArgSet nset = 0) const

Evalute all parameters/observables, and then evaluate formula.

Evaluate the internal TFormula.

First, all variables serving this instance are evaluated given the normalisation set, and then the formula is evaluated.

Parameters
[in]nsetNormalisation set passed to evaluation of arguments serving values.
Returns
The result of the evaluation.

Definition at line 344 of file RooFormula.cxx.

◆ evaluateSpan()

RooSpan< double > RooFormula::evaluateSpan ( const RooAbsReal dataOwner,
BatchHelpers::RunContext inputData,
const RooArgSet nset = nullptr 
) const

Definition at line 370 of file RooFormula.cxx.

◆ formulaString()

std::string RooFormula::formulaString ( ) const
inline

Definition at line 81 of file RooFormula.h.

◆ getParameter() [1/2]

RooAbsArg* RooFormula::getParameter ( const char *  name) const
inline

Return pointer to the parameter with given name.

Returns
Parameter if in use, nullptr if not in use.

Definition at line 49 of file RooFormula.h.

◆ getParameter() [2/2]

RooAbsArg* RooFormula::getParameter ( Int_t  index) const
inline

Return pointer to parameter at given index.

This returns irrespective of whether the parameter is in use.

Definition at line 55 of file RooFormula.h.

◆ installFormulaOrThrow()

void RooFormula::installFormulaOrThrow ( const std::string &  formulaa)
private

Check that the formula compiles, and also fulfills the assumptions.

Definition at line 479 of file RooFormula.cxx.

◆ ok()

Bool_t RooFormula::ok ( ) const
inline

Definition at line 59 of file RooFormula.h.

◆ operator=()

RooFormula& RooFormula::operator= ( const RooFormula other)
private

◆ Print()

virtual void RooFormula::Print ( Option_t option = 0) const
inlinevirtual

Print TNamed name and title.

Reimplemented from TNamed.

Definition at line 76 of file RooFormula.h.

◆ printArgs()

void RooFormula::printArgs ( std::ostream &  os) const
virtual

Print arguments of formula, i.e. dependents that are actually used.

Reimplemented from RooPrintable.

Definition at line 466 of file RooFormula.cxx.

◆ printClassName()

void RooFormula::printClassName ( std::ostream &  os) const
virtual

Print class name of formula.

Reimplemented from RooPrintable.

Definition at line 457 of file RooFormula.cxx.

◆ printMultiline()

void RooFormula::printMultiline ( std::ostream &  os,
Int_t  contents,
Bool_t  verbose = kFALSE,
TString  indent = "" 
) const
virtual

Printing interface.

Reimplemented from RooPrintable.

Definition at line 416 of file RooFormula.cxx.

◆ printName()

void RooFormula::printName ( std::ostream &  os) const
virtual

Print name of formula.

Reimplemented from RooPrintable.

Definition at line 439 of file RooFormula.cxx.

◆ printTitle()

void RooFormula::printTitle ( std::ostream &  os) const
virtual

Print title of formula.

Reimplemented from RooPrintable.

Definition at line 448 of file RooFormula.cxx.

◆ printValue()

void RooFormula::printValue ( std::ostream &  os) const
virtual

Print value of formula.

Reimplemented from RooPrintable.

Definition at line 430 of file RooFormula.cxx.

◆ processFormula()

std::string RooFormula::processFormula ( std::string  formula) const
private

Process given formula by replacing all ordinal and name references by x[i], where i matches the position of the argument in _origList.

Further, references to category states such as leptonMulti:one are replaced by the category index.

Definition at line 156 of file RooFormula.cxx.

◆ reCompile()

Bool_t RooFormula::reCompile ( const char *  newFormula)

Recompile formula with new expression.

In case of error, the old formula is retained.

Definition at line 283 of file RooFormula.cxx.

◆ reconstructFormula()

std::string RooFormula::reconstructFormula ( std::string  internalRepr) const
private

From the internal representation, construct a formula by replacing all index place holders with the names of the variables that are being used to evaluate it.

Definition at line 261 of file RooFormula.cxx.

◆ usedVariables()

RooArgList RooFormula::usedVariables ( ) const
private

Analyse internal formula to find out which variables are actually in use.

Definition at line 231 of file RooFormula.cxx.

Member Data Documentation

◆ _isCategory

std::vector<bool> RooFormula::_isCategory
private

Original list of dependents.

Definition at line 93 of file RooFormula.h.

◆ _origList

RooArgList RooFormula::_origList
private

Definition at line 92 of file RooFormula.h.

◆ _tFormula

std::unique_ptr<TFormula> RooFormula::_tFormula
private

Whether an element of the _origList is a category.

Definition at line 94 of file RooFormula.h.

Libraries for RooFormula:
[legend]

The documentation for this class was generated from the following files:
RooFormula::RooFormula
RooFormula()
Default constructor coverity[UNINIT_CTOR].
Definition: RooFormula.cxx:99
RooArgList
RooArgList is a container object that can hold multiple RooAbsArg objects.
Definition: RooArgList.h:21
x
Double_t x[n]
Definition: legend1.C:17
y
Double_t y[n]
Definition: legend1.C:17