[u/mrichter/AliRoot.git] / RICH / api.txt

How to open session?
	use static methode  AliRunLoader::Open("galice.root","AlicE","update")
How to retrive pointer to alice run loader:
        use pRICH->GetLoader()->GetRunLoader() (all detector classes inherit from AliDetector wich has GetLoader())
	use methode AliRun::GetRunLoader for gAlice (depricated)
How to get pointers to deifferent root trees:
	TreeE belongs to AliRunLoader, available after AliRunLoader::LoadHeader()
	TreeK belongs to AliRunLoader, available after AliRunLoader::LoadKinematics()
	TreeH belongs to AliLoader   , available after AliLoader::LoadHits()
	TreeS belongs to AliLoader   , available after AliLoader::LoadSDigits()
	TreeD belongs to AliLoader   , available after AliLoader::LoadDigits()
	TreeR belongs to AliLoader   , available after AliLoader::LoadRecPoints()


How to work with the stack of particles?
	- pointer to the stack is returned by gAlice->Stack() (global gAlice of type AliRun) or AliRunLoader::Stack() but
        before one needs to load event header by AliRunLoader::LoadHeader() otherwise both methods return 0.
        Moreover loading header gives the information about number of particles only. 
        To retrive the list of particle one also needs to load kinematics by AliRunLoader::LoadKinematics()        
	- total amount of particles in stack for a given event:         AliRunLoader::Stack()->GetNtrack() or AliRun::GetEvent() (after LoadHeader())
	- total amount of primiry particles in stack for a given event: AliRunLoader::Stack()->GetNprimary() or AliLoader::TreeH()->GetEntries() (after LoadHeader())


How to retrive hits:
	Hits a stored on primiry by primiry basis. To retrieve all hits one needs to do:
	initialise the root tree and containers:    AliLoader::LoadHits() 
	read number of primiries in current event:
	loop on the list of primiries:


How to retrive sdigits? 
	Sdigits stored in tree S with the branch of TClonesArray, all sdigits in a single TClonesArray
	So the tree has only one entry.
	One needs to say:
	pRich->GetLoader()->LoadSDigits(); this one open file, get the tree and invoke AliRICH::SetTreeAddress()    


gAlice->GetMCApp()->GetCurrentTrackNumber()


What are the debug methodes avail:
	AliModule::GetDebug() 
	AliModule::SetDebug()
	AliRun::GetDebug()
	AliRun::SetDebug()


How to get info for tid number?
	Header and Kinematics trees must be loaded, then possible to retrive pointer to Stack of particles
	Int_t AliRunLoader::LoadHeader(); Int_t AliRunLoader::LoadKinematics()
	AliStack *AliRunLoader::Stack()
	TParticle *AliStack::Particle(tid)
	TParticle::Print()

How to deal with AliRunDigitizer?
	AliRunDigitizer::Exec() just call AliRunDigitizer::Digitize()	

How to avoid using gAlice?
	Rich()->GetLoader()->GetRunLoader()->GetAliRun() returns gAlice global pointer.
Commit	Line	Data
ab6b554e	1	How to open session?
	2	use static methode AliRunLoader::Open("galice.root","AlicE","update")
	3	How to retrive pointer to alice run loader:
	4	use pRICH->GetLoader()->GetRunLoader() (all detector classes inherit from AliDetector wich has GetLoader())
	5	use methode AliRun::GetRunLoader for gAlice (depricated)
	6	How to get pointers to deifferent root trees:
	7	TreeE belongs to AliRunLoader, available after AliRunLoader::LoadHeader()
	8	TreeK belongs to AliRunLoader, available after AliRunLoader::LoadKinematics()
	9	TreeH belongs to AliLoader , available after AliLoader::LoadHits()
	10	TreeS belongs to AliLoader , available after AliLoader::LoadSDigits()
	11	TreeD belongs to AliLoader , available after AliLoader::LoadDigits()
	12	TreeR belongs to AliLoader , available after AliLoader::LoadRecPoints()
	13
	14
7185d942	15	How to work with the stack of particles?
ab6b554e	16	- pointer to the stack is returned by gAlice->Stack() (global gAlice of type AliRun) or AliRunLoader::Stack() but
	17	before one needs to load event header by AliRunLoader::LoadHeader() otherwise both methods return 0.
	18	Moreover loading header gives the information about number of particles only.
	19	To retrive the list of particle one also needs to load kinematics by AliRunLoader::LoadKinematics()
	20	- total amount of particles in stack for a given event: AliRunLoader::Stack()->GetNtrack() or AliRun::GetEvent() (after LoadHeader())
	21	- total amount of primiry particles in stack for a given event: AliRunLoader::Stack()->GetNprimary() or AliLoader::TreeH()->GetEntries() (after LoadHeader())
3582c1f9	22
3582c1f9	23
3582c1f9	24
09c52ebc	25	How to retrive hits:
	26	Hits a stored on primiry by primiry basis. To retrieve all hits one needs to do:
	27	initialise the root tree and containers: AliLoader::LoadHits()
	28	read number of primiries in current event:
	29	loop on the list of primiries:
3582c1f9	30
3582c1f9	31
3582c1f9	32
09c52ebc	33	How to retrive sdigits?
	34	Sdigits stored in tree S with the branch of TClonesArray, all sdigits in a single TClonesArray
	35	So the tree has only one entry.
	36	One needs to say:
	37	pRich->GetLoader()->LoadSDigits(); this one open file, get the tree and invoke AliRICH::SetTreeAddress()
3582c1f9	38
	39
	40
	41	gAlice->GetMCApp()->GetCurrentTrackNumber()
	42
	43
7185d942	44	What are the debug methodes avail:
	45	AliModule::GetDebug()
	46	AliModule::SetDebug()
	47	AliRun::GetDebug()
	48	AliRun::SetDebug()
3582c1f9	49
3582c1f9	50
09c52ebc	51	How to get info for tid number?
	52	Header and Kinematics trees must be loaded, then possible to retrive pointer to Stack of particles
	53	Int_t AliRunLoader::LoadHeader(); Int_t AliRunLoader::LoadKinematics()
	54	AliStack *AliRunLoader::Stack()
	55	TParticle *AliStack::Particle(tid)
	56	TParticle::Print()
3582c1f9	57
09c52ebc	58	How to deal with AliRunDigitizer?
09c52ebc	59	AliRunDigitizer::Exec() just call AliRunDigitizer::Digitize()
3582c1f9	60
7185d942	61	How to avoid using gAlice?
	62	Rich()->GetLoader()->GetRunLoader()->GetAliRun() returns gAlice global pointer.
	63
3582c1f9	64
3582c1f9	65