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ROOT 6.10/09 Reference Guide |
The interface to various event generators.
Is an base class, that defines the interface of ROOT to various event generators. Every event generator should inherit from TGenerator or its subclasses.
Derived class can overload the member function GenerateEvent to do the actual event generation (e.g., call PYEVNT or similar).
The derived class should overload the member function ImportParticles (both types) to read the internal storage of the generated event into either the internal TObjArray or the passed TClonesArray of TParticles.
If the generator code stores event data in the /HEPEVT/ common block Then the default implementation of ImportParticles should suffice. The common block /HEPEVT/ is structed like
// C typedef struct { Int_t nevhep; // Event number Int_t nhep; // # of particles Int_t isthep[4000]; // Status flag of i'th particle Int_t idhep[4000]; // PDG # of particle Int_t jmohep[4000][2]; // 1st & 2nd mother particle # Int_t jdahep[4000][2]; // 1st & 2nd daughter particle # Double_t phep[4000][5]; // 4-momentum and 1 word Double_t vhep[4000][4]; // 4-position of production } HEPEVT_DEF; C Fortran COMMON/HEPEVT/NEVHEP,NHEP,ISTHEP(4000),IDHEP(4000), + JMOHEP(2,4000),JDAHEP(2,4000),PHEP(5,4000),VHEP(4,4000) INTEGER NEVHEP,NHEP,ISTHEP,IDHEP,JMOHEP,JDAHEP DOUBLE PRECISION PHEP,VHEP
The generic member functions SetParameter and GetParameter can be overloaded to set and get parameters of the event generator.
Note, if the derived class interfaces a (set of) Fortran common blocks (like TPythia, TVenus does), one better make the derived class a singleton. That is, something like
class MyGenerator : public TGenerator { public: static MyGenerator* Instance() { if (!fgInstance) fgInstance = new MyGenerator; return fgInstance; } void GenerateEvent() { ... } void ImportParticles(TClonesArray* a, Option_t opt="") {...} Int_t ImportParticles(Option_t opt="") { ... } Int_t SetParameter(const char* name, Double_t val) { ... } Double_t GetParameter(const char* name) { ... } virtual ~MyGenerator() { ... } protected: MyGenerator() { ... } MyGenerator(const MyGenerator& o) { ... } MyGenerator& operator=(const MyGenerator& o) { ... } static MyGenerator* fgInstance; ClassDef(MyGenerator,0); };
Having multiple objects accessing the same common blocks is not safe.
Concrete TGenerator classes can be loaded in scripts and subseqent- ly used in compiled code:
// MyRun.h class MyRun : public TObject { public: static MyRun* Instance() { ... } void SetGenerator(TGenerator* g) { fGenerator = g; } void Run(Int_t n, Option_t* option="") { TFile* file = TFile::Open("file.root","RECREATE"); TTree* tree = new TTree("T","T"); TClonesArray* p = new TClonesArray("TParticles"); tree->Branch("particles", &p); for (Int_t event = 0; event < n; event++) { fGenerator->GenerateEvent(); fGenerator->ImportParticles(p,option); tree->Fill(); } file->Write(); file->Close(); } ... protected: TGenerator* fGenerator; ClassDef(MyRun,0); }; // Config.C void Config() { MyRun* run = MyRun::Instance(); run->SetGenerator(MyGenerator::Instance()); } // main.cxx int main(int argc, char** argv) { TApplication app("", 0, 0); gSystem->ProcessLine(".x Config.C"); MyRun::Instance()->Run(10); return 0; }
This is especially useful for example with TVirtualMC or similar.
Definition at line 144 of file TGenerator.h.
Public Member Functions | |
TGenerator () | |
TGenerator (const char *name, const char *title="Generator class") | |
Event generator default constructor. More... | |
virtual | ~TGenerator () |
Event generator default destructor. More... | |
virtual void | Browse (TBrowser *b) |
browse generator More... | |
virtual Int_t | DistancetoPrimitive (Int_t px, Int_t py) |
Compute distance from point px,py to objects in event. More... | |
virtual void | Draw (Option_t *option="") |
Insert one event in the pad list. More... | |
virtual void | ExecuteEvent (Int_t event, Int_t px, Int_t py) |
Execute action corresponding to one event. More... | |
virtual void | GenerateEvent () |
must be implemented in concrete class (see eg TPythia6) More... | |
virtual TObjArray * | GetListOfParticles () const |
Int_t | GetNumberOfParticles () const |
Return the number of particles in the stack. More... | |
virtual Double_t | GetParameter (const char *) const |
virtual TParticle * | GetParticle (Int_t i) const |
Returns pointer to primary number i;. More... | |
virtual TObjArray * | GetPrimaries (Option_t *option="") |
Float_t | GetPtCut () const |
virtual Int_t | ImportParticles (TClonesArray *particles, Option_t *option="") |
It reads the /HEPEVT/ common block which has been filled by the GenerateEvent method. More... | |
virtual TObjArray * | ImportParticles (Option_t *option="") |
It reads the /HEPEVT/ common block which has been filled by the GenerateEvent method. More... | |
virtual void | Paint (Option_t *option="") |
Paint one event. More... | |
virtual void | SetParameter (const char *, Double_t) |
virtual void | SetPtCut (Float_t ptcut=0) |
Set Pt threshold below which primaries are not drawn. More... | |
virtual void | SetViewRadius (Float_t rbox=1000) |
Set lower and upper values of the view range. More... | |
virtual void | SetViewRange (Float_t xmin=-10000, Float_t ymin=-10000, Float_t zmin=-10000, Float_t xmax=10000, Float_t ymax=10000, Float_t zmax=10000) |
Set lower and upper values of the view range. More... | |
virtual void | ShowNeutrons (Bool_t show=1) |
Set flag to display or not neutrons. More... | |
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TNamed () | |
TNamed (const char *name, const char *title) | |
TNamed (const TString &name, const TString &title) | |
TNamed (const TNamed &named) | |
TNamed copy ctor. More... | |
virtual | ~TNamed () |
virtual void | Clear (Option_t *option="") |
Set name and title to empty strings (""). More... | |
virtual TObject * | Clone (const char *newname="") const |
Make a clone of an object using the Streamer facility. More... | |
virtual Int_t | Compare (const TObject *obj) const |
Compare two TNamed objects. More... | |
virtual void | Copy (TObject &named) const |
Copy this to obj. More... | |
virtual void | FillBuffer (char *&buffer) |
Encode TNamed into output buffer. More... | |
virtual const char * | GetName () const |
Returns name of object. More... | |
virtual const char * | GetTitle () const |
Returns title of object. More... | |
virtual ULong_t | Hash () const |
Return hash value for this object. More... | |
virtual Bool_t | IsSortable () const |
virtual void | ls (Option_t *option="") const |
List TNamed name and title. More... | |
TNamed & | operator= (const TNamed &rhs) |
TNamed assignment operator. More... | |
virtual void | Print (Option_t *option="") const |
Print TNamed name and title. 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... | |
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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 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 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 | 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 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 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 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... | |
Bool_t | IsOnHeap () const |
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... | |
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 | 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, Bool_t set) |
Set or unset the user status bits as specified in f. More... | |
void | SetBit (UInt_t f) |
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... | |
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 | |
TGenerator (const TGenerator &tg) | |
TGenerator & | operator= (const TGenerator &tg) |
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virtual void | DoError (int level, const char *location, const char *fmt, va_list va) const |
Interface to ErrorHandler (protected). More... | |
void | MakeZombie () |
Protected Attributes | |
TObjArray * | fParticles |
display neutrons if true More... | |
Float_t | fPtCut |
Bool_t | fShowNeutrons |
Pt cut. Do not show primaries below. More... | |
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TString | fName |
TString | fTitle |
Additional Inherited Members | |
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enum | { kIsOnHeap = 0x01000000, kNotDeleted = 0x02000000, kZombie = 0x04000000, kBitMask = 0x00ffffff } |
enum | { kSingleKey = BIT(0), kOverwrite = BIT(1), kWriteDelete = BIT(2) } |
enum | EStatusBits { kCanDelete = BIT(0), kMustCleanup = BIT(3), kObjInCanvas = BIT(3), kIsReferenced = BIT(4), kHasUUID = BIT(5), kCannotPick = BIT(6), kNoContextMenu = BIT(8), kInvalidObject = BIT(13) } |
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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... | |
#include <TGenerator.h>
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inlineprotected |
Definition at line 151 of file TGenerator.h.
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inline |
Definition at line 163 of file TGenerator.h.
TGenerator::TGenerator | ( | const char * | name, |
const char * | title = "Generator class" |
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Event generator default constructor.
Definition at line 160 of file TGenerator.cxx.
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virtual |
Event generator default destructor.
Definition at line 176 of file TGenerator.cxx.
Compute distance from point px,py to objects in event.
Reimplemented from TObject.
Definition at line 334 of file TGenerator.cxx.
Insert one event in the pad list.
Reimplemented from TObject.
Definition at line 348 of file TGenerator.cxx.
Execute action corresponding to one event.
Reimplemented from TObject.
Definition at line 495 of file TGenerator.cxx.
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virtual |
must be implemented in concrete class (see eg TPythia6)
Reimplemented in TPythia6, and TPythia8.
Definition at line 189 of file TGenerator.cxx.
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inlinevirtual |
Definition at line 176 of file TGenerator.h.
Int_t TGenerator::GetNumberOfParticles | ( | ) | const |
Return the number of particles in the stack.
Definition at line 506 of file TGenerator.cxx.
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inlinevirtual |
Definition at line 171 of file TGenerator.h.
Returns pointer to primary number i;.
Definition at line 515 of file TGenerator.cxx.
Definition at line 177 of file TGenerator.h.
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inline |
Definition at line 178 of file TGenerator.h.
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virtual |
It reads the /HEPEVT/ common block which has been filled by the GenerateEvent method.
If the event generator does not use the HEPEVT common block, This routine has to be overloaded by the subclasses.
The function loops on the generated particles and store them in the TClonesArray pointed by the argument particles. The default action is to store only the stable particles (ISTHEP = 1) This can be demanded explicitly by setting the option = "Final" If the option = "All", all the particles are stored.
Reimplemented in TPythia6, and TPythia8.
Definition at line 270 of file TGenerator.cxx.
It reads the /HEPEVT/ common block which has been filled by the GenerateEvent method.
If the event generator does not use the HEPEVT common block, This routine has to be overloaded by the subclasses.
The default action is to store only the stable particles (ISTHEP = 1) This can be demanded explicitly by setting the option = "Final" If the option = "All", all the particles are stored.
Reimplemented in TPythia6, and TPythia8.
Definition at line 205 of file TGenerator.cxx.
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inlineprotected |
Definition at line 153 of file TGenerator.h.
Definition at line 180 of file TGenerator.h.
Set Pt threshold below which primaries are not drawn.
Definition at line 537 of file TGenerator.cxx.
Set lower and upper values of the view range.
Definition at line 549 of file TGenerator.cxx.
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virtual |
Set lower and upper values of the view range.
Definition at line 559 of file TGenerator.cxx.
Set flag to display or not neutrons.
Definition at line 574 of file TGenerator.cxx.
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protected |
display neutrons if true
Definition at line 149 of file TGenerator.h.
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protected |
Definition at line 147 of file TGenerator.h.
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protected |
Pt cut. Do not show primaries below.
Definition at line 148 of file TGenerator.h.