[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 different 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?
        - first of all, the stack includes primary as well as secondary particles
	- pointer to the stack is returned by AliRun::Stack() (global gAlice of type AliRun - depricated way to do)
          or by 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:         AliStack::GetNtrack() or AliRun::GetEvent() (after LoadHeader())
	- total amount of primiry particles in stack for a given event: AliStack::GetNprimary() or AliLoader::TreeH()->GetEntries() (after LoadHeader())


How to retrive hits:
	Hits a stored on primary by primary basis. To retrieve all hits one needs to do:
	initialise the root tree and containers:    AliLoader::LoadHits() 
	read number of primaries 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()    

What are the debug methodes avail:
	AliModule::GetDebug() now depricated, use AliDebug printout instead
	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)
998b831f	6	How to get pointers to different root trees:
ab6b554e	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?
998b831f	16	- first of all, the stack includes primary as well as secondary particles
	17	- pointer to the stack is returned by AliRun::Stack() (global gAlice of type AliRun - depricated way to do)
	18	or by AliRunLoader::Stack() but before one needs to load event header by AliRunLoader::LoadHeader() otherwise both methods return 0.
	19	Moreover loading header gives the information about number of particles only.
	20	To retrive the list of particle one also needs to load kinematics by AliRunLoader::LoadKinematics()
	21	- total amount of particles in stack for a given event: AliStack::GetNtrack() or AliRun::GetEvent() (after LoadHeader())
	22	- total amount of primiry particles in stack for a given event: AliStack::GetNprimary() or AliLoader::TreeH()->GetEntries() (after LoadHeader())
3582c1f9	23
3582c1f9	24
3582c1f9	25
09c52ebc	26	How to retrive hits:
998b831f	27	Hits a stored on primary by primary basis. To retrieve all hits one needs to do:
09c52ebc	28	initialise the root tree and containers: AliLoader::LoadHits()
998b831f	29	read number of primaries in current event:
09c52ebc	30	loop on the list of primiries:
3582c1f9	31
3582c1f9	32
3582c1f9	33
09c52ebc	34	How to retrive sdigits?
	35	Sdigits stored in tree S with the branch of TClonesArray, all sdigits in a single TClonesArray
	36	So the tree has only one entry.
	37	One needs to say:
	38	pRich->GetLoader()->LoadSDigits(); this one open file, get the tree and invoke AliRICH::SetTreeAddress()
3582c1f9	39
7185d942	40	What are the debug methodes avail:
998b831f	41	AliModule::GetDebug() now depricated, use AliDebug printout instead
7185d942	42	AliModule::SetDebug()
	43	AliRun::GetDebug()
	44	AliRun::SetDebug()
3582c1f9	45
3582c1f9	46
09c52ebc	47	How to get info for tid number?
	48	Header and Kinematics trees must be loaded, then possible to retrive pointer to Stack of particles
	49	Int_t AliRunLoader::LoadHeader(); Int_t AliRunLoader::LoadKinematics()
	50	AliStack *AliRunLoader::Stack()
	51	TParticle *AliStack::Particle(tid)
	52	TParticle::Print()
3582c1f9	53
09c52ebc	54	How to deal with AliRunDigitizer?
09c52ebc	55	AliRunDigitizer::Exec() just call AliRunDigitizer::Digitize()
3582c1f9	56
7185d942	57	How to avoid using gAlice?
	58	Rich()->GetLoader()->GetRunLoader()->GetAliRun() returns gAlice global pointer.
	59