[u/mrichter/AliRoot.git] / STEER / AliLego.cxx

/**************************************************************************
 * Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
 *                                                                        *
 * Author: The ALICE Off-line Project.                                    *
 * Contributors are mentioned in the code where appropriate.              *
 *                                                                        *
 * Permission to use, copy, modify and distribute this software and its   *
 * documentation strictly for non-commercial purposes is hereby granted   *
 * without fee, provided that the above copyright notice appears in all   *
 * copies and that both the copyright notice and this permission notice   *
 * appear in the supporting documentation. The authors make no claims     *
 * about the suitability of this software for any purpose. It is          *
 * provided "as is" without express or implied warranty.                  *
 **************************************************************************/

/*
$Log$
Revision 1.9  1999/12/03 10:54:01  fca
Fix lego summary

Revision 1.8  1999/10/01 09:54:33  fca
Correct logics for Lego StepManager

Revision 1.7  1999/09/29 09:24:29  fca
Introduction of the Copyright and cvs Log

*/

//////////////////////////////////////////////////////////////
//////////////////////////////////////////////////////////////
//                            
//  Utility class to evaluate the material budget from
//  a given radius to the surface of an arbitrary cylinder
//  along radial directions from the centre:
// 
//   - radiation length
//   - Interaction length
//   - g/cm2
// 
//  Geantinos are shot in the bins in the fNtheta bins in theta
//  and fNphi bins in phi with specified rectangular limits.
//  The statistics are accumulated per
//    fRadMin < r < fRadMax    and  <0 < z < fZMax
//
//  To activate this option, you can do:
//      Root > gAlice.RunLego();
//  or  Root > .x menu.C  then select menu item "RunLego"
//  Note that when calling gAlice->RunLego, an optional list
//  of arguments may be specified.
//
//Begin_Html
/*
<img src="picts/alilego.gif">
*/
//End_Html
//
//////////////////////////////////////////////////////////////

#include "TMath.h"
#include "AliLego.h"
#include "AliRun.h"
#include "AliConst.h"
#include "AliVMC.h"

ClassImp(AliLego)


//___________________________________________
AliLego::AliLego()
{
   fHistRadl = 0;
   fHistAbso = 0;
   fHistGcm2 = 0;
   fHistReta = 0;
}

//___________________________________________
AliLego::AliLego(const char *title, Int_t ntheta, Float_t themin, Float_t themax,
		 Int_t nphi, Float_t phimin, Float_t phimax,
		 Float_t rmin, Float_t rmax, Float_t zmax)
  : TNamed("Lego Generator",title)
{
// specify the angular limits and the size of the rectangular box
   
   fGener = new AliLegoGenerator(ntheta, themin, themax,
		       nphi, phimin, phimax, rmin, rmax, zmax);
   
   gAlice->SetGenerator(fGener);

   Float_t etamin = -TMath::Log(TMath::Tan(TMath::Min((Double_t)themax*kDegrad/2,TMath::Pi()/2-1.e-10)));
   Float_t etamax = -TMath::Log(TMath::Tan(TMath::Max((Double_t)themin*kDegrad/2,              1.e-10)));

   fHistRadl = new TH2F("hradl","Radiation length map",    
			nphi,phimin,phimax,ntheta,themin,themax);
   fHistAbso = new TH2F("habso","Interaction length map",  
			nphi,phimin,phimax,ntheta,themin,themax);
   fHistGcm2 = new TH2F("hgcm2","g/cm2 length map",        
			nphi,phimin,phimax,ntheta,themin,themax);
   fHistReta = new TH2F("hetar","Radiation length vs. eta",
			nphi,phimin,phimax,ntheta,etamin,etamax);

}

//___________________________________________
AliLego::~AliLego()
{
   delete fHistRadl;
   delete fHistAbso;
   delete fHistGcm2;
   delete fHistReta;
}


//___________________________________________
void AliLego::Run()
{
   // loop on phi,theta bins
   gMC->InitLego();
   Float_t thed, phid, eta;
   for (Int_t i=0; i<=fGener->Nphi()*fGener->Ntheta(); ++i) {
// --- Set to 0 radiation length, absorption length and g/cm2 ---
     fTotRadl = 0;
     fTotAbso = 0;
     fTotGcm2 = 0;
     
     gVMC->ProcessEvent();
     
     thed = fGener->CurTheta()*kRaddeg;
     phid = fGener->CurPhi()*kRaddeg;
     eta  = -TMath::Log(TMath::Tan(TMath::Max(
	     TMath::Min((Double_t)(fGener->CurTheta())/2,
			TMath::Pi()/2-1.e-10),1.e-10)));

     fHistRadl->Fill(phid,thed,fTotRadl);
     fHistAbso->Fill(phid,thed,fTotAbso);
     fHistGcm2->Fill(phid,thed,fTotGcm2);
     fHistReta->Fill(phid,eta,fTotRadl);
     gAlice->FinishEvent();
   }
   // store histograms in current Root file
   fHistRadl->Write();
   fHistAbso->Write();
   fHistGcm2->Write();
   fHistReta->Write();
}

//___________________________________________
void AliLego::StepManager()
{
// called from AliRun::Stepmanager from gustep.
// Accumulate the 3 parameters step by step
  
   static Float_t t;
   Float_t a,z,dens,radl,absl;
   Int_t i;
   
   Float_t step  = gMC->TrackStep();
       
   Float_t vect[3], dir[3];
   TLorentzVector pos, mom;

   gMC->TrackPosition(pos);  
   gMC->TrackMomentum(mom);
   gMC->CurrentMaterial(a,z,dens,radl,absl);
   
   if (z < 1) return;
   
// --- See if we have to stop now
   if (TMath::Abs(pos[2]) > fGener->ZMax()  || 
       pos[0]*pos[0] +pos[1]*pos[1] > fGener->RadMax()*fGener->RadMax()) {
     if (gMC->TrackLength()) {
       // Not the first step, add past contribution
       fTotAbso += t/absl;
       fTotRadl += t/radl;
       fTotGcm2 += t*dens;
     }
     gMC->StopTrack();
     return;
   }

// --- See how long we have to go
   for(i=0;i<3;++i) {
     vect[i]=pos[i];
     dir[i]=mom[i];
   }

   t  = fGener->PropagateCylinder(vect,dir,fGener->RadMax(),fGener->ZMax());

   if(step) {
     fTotAbso += step/absl;
     fTotRadl += step/radl;
     fTotGcm2 += step*dens;
   }
}

ClassImp(AliLegoGenerator)

//___________________________________________
AliLegoGenerator::AliLegoGenerator(Int_t ntheta, Float_t themin,
				   Float_t themax, Int_t nphi, 
				   Float_t phimin, Float_t phimax,
				   Float_t rmin, Float_t rmax, Float_t zmax) :
  AliGenerator(0), fRadMin(rmin), fRadMax(rmax), fZMax(zmax), fNtheta(ntheta),
  fNphi(nphi), fThetaBin(ntheta), fPhiBin(-1), fCurTheta(0), fCurPhi(0)
  
{
  SetPhiRange(phimin,phimax);
  SetThetaRange(themin,themax);
  SetName("Lego");
}


//___________________________________________
void AliLegoGenerator::Generate()
{
// Create a geantino with kinematics corresponding to the current
// bins in theta and phi.
   
  //
  // Rootinos are 0
   const Int_t mpart = 0;
   Float_t orig[3], pmom[3];
   Float_t t, cost, sint, cosp, sinp;
   
   // Prepare for next step
   if(fThetaBin>=fNtheta-1)
     if(fPhiBin>=fNphi-1) {
       Warning("Generate","End of Lego Generation");
       return;
     } else { 
       fPhiBin++;
       printf("Generating rays in phi bin:%d\n",fPhiBin);
       fThetaBin=0;
     } else fThetaBin++;

   fCurTheta = (fThetaMin+(fThetaBin+0.5)*(fThetaMax-fThetaMin)/fNtheta);
   fCurPhi   = (fPhiMin+(fPhiBin+0.5)*(fPhiMax-fPhiMin)/fNphi);
   cost      = TMath::Cos(fCurTheta);
   sint      = TMath::Sin(fCurTheta);
   cosp      = TMath::Cos(fCurPhi);
   sinp      = TMath::Sin(fCurPhi);
   
   pmom[0] = cosp*sint;
   pmom[1] = sinp*sint;
   pmom[2] = cost;
   
   // --- Where to start
   orig[0] = orig[1] = orig[2] = 0;
   Float_t dalicz = 3000;
   if (fRadMin > 0) {
     t = PropagateCylinder(orig,pmom,fRadMin,dalicz);
     orig[0] = pmom[0]*t;
     orig[1] = pmom[1]*t;
     orig[2] = pmom[2]*t;
     if (TMath::Abs(orig[2]) > fZMax) return;
   }
   
   Float_t polar[3]={0.,0.,0.};
   Int_t ntr;
   gAlice->SetTrack(1, 0, mpart, pmom, orig, polar, 0, "LEGO ray", ntr);

}

//___________________________________________
Float_t AliLegoGenerator::PropagateCylinder(Float_t *x, Float_t *v, Float_t r, Float_t z)
{
// Propagate to cylinder from inside

   Double_t hnorm, sz, t, t1, t2, t3, sr;
   Double_t d[3];
   const Float_t kSmall  = 1e-8;
   const Float_t kSmall2 = kSmall*kSmall;

// ---> Find intesection with Z planes
   d[0]  = v[0];
   d[1]  = v[1];
   d[2]  = v[2];
   hnorm = TMath::Sqrt(1/(d[0]*d[0]+d[1]*d[1]+d[2]*d[2]));
   d[0] *= hnorm;
   d[1] *= hnorm;
   d[2] *= hnorm;
   if (d[2] > kSmall)       sz = (z-x[2])/d[2];
   else if (d[2] < -kSmall) sz = -(z+x[2])/d[2];
   else                     sz = 1.e10;  // ---> Direction parallel to X-Y, no intersection

// ---> Intersection with cylinders
//      Intersection point (x,y,z)
//      (x,y,z) is on track :    x=X(1)+t*D(1)
//                               y=X(2)+t*D(2)
//                               z=X(3)+t*D(3)
//      (x,y,z) is on cylinder : x**2 + y**2 = R**2
//
//      (D(1)**2+D(2)**2)*t**2
//      +2.*(X(1)*D(1)+X(2)*D(2))*t
//      +X(1)**2+X(2)**2-R**2=0
// ---> Solve second degree equation
   t1 = d[0]*d[0] + d[1]*d[1];
   if (t1 <= kSmall2) {
      t = sz;  // ---> Track parallel to the z-axis, take distance to planes
   } else {
      t2 = x[0]*d[0] + x[1]*d[1];
      t3 = x[0]*x[0] + x[1]*x[1];
      // ---> It should be positive, but there may be numerical problems
      sr = (t2 +TMath::Sqrt(TMath::Max(t2*t2-(t3-r*r)*t1,0.)))/t1;
      // ---> Find minimum distance between planes and cylinder
      t  = TMath::Min(sz,sr);
   }
   return t;
}
Commit	Line	Data
4c039060	1	/**************************************************************************
	2	* Copyright(c) 1998-1999, ALICE Experiment at CERN, All rights reserved. *
	3	* *
	4	* Author: The ALICE Off-line Project. *
	5	* Contributors are mentioned in the code where appropriate. *
	6	* *
	7	* Permission to use, copy, modify and distribute this software and its *
	8	* documentation strictly for non-commercial purposes is hereby granted *
	9	* without fee, provided that the above copyright notice appears in all *
	10	* copies and that both the copyright notice and this permission notice *
	11	* appear in the supporting documentation. The authors make no claims *
	12	* about the suitability of this software for any purpose. It is *
	13	* provided "as is" without express or implied warranty. *
	14	**************************************************************************/
	15
	16	/*
	17	$Log$
b13db077	18	Revision 1.9 1999/12/03 10:54:01 fca
	19	Fix lego summary
	20
00719c1b	21	Revision 1.8 1999/10/01 09:54:33 fca
	22	Correct logics for Lego StepManager
	23
f059c84a	24	Revision 1.7 1999/09/29 09:24:29 fca
	25	Introduction of the Copyright and cvs Log
	26
4c039060	27	*/
4c039060	28
fe4da5cc	29	//////////////////////////////////////////////////////////////
	30	//////////////////////////////////////////////////////////////
	31	//
	32	// Utility class to evaluate the material budget from
	33	// a given radius to the surface of an arbitrary cylinder
	34	// along radial directions from the centre:
	35	//
	36	// - radiation length
	37	// - Interaction length
	38	// - g/cm2
	39	//
	40	// Geantinos are shot in the bins in the fNtheta bins in theta
	41	// and fNphi bins in phi with specified rectangular limits.
	42	// The statistics are accumulated per
	43	// fRadMin < r < fRadMax and <0 < z < fZMax
	44	//
	45	// To activate this option, you can do:
	46	// Root > gAlice.RunLego();
	47	// or Root > .x menu.C then select menu item "RunLego"
	48	// Note that when calling gAlice->RunLego, an optional list
	49	// of arguments may be specified.
	50	//
	51	//Begin_Html
	52	/*
1439f98e	53	<img src="picts/alilego.gif">
fe4da5cc	54	*/
	55	//End_Html
	56	//
	57	//////////////////////////////////////////////////////////////
	58
	59	#include "TMath.h"
1578254f	60	#include "AliLego.h"
fe4da5cc	61	#include "AliRun.h"
fe4da5cc	62	#include "AliConst.h"
b13db077	63	#include "AliVMC.h"
fe4da5cc	64
	65	ClassImp(AliLego)
	66
	67
	68	//___________________________________________
	69	AliLego::AliLego()
	70	{
	71	fHistRadl = 0;
	72	fHistAbso = 0;
	73	fHistGcm2 = 0;
	74	fHistReta = 0;
	75	}
	76
	77	//___________________________________________
b13db077	78	AliLego::AliLego(const char *title, Int_t ntheta, Float_t themin, Float_t themax,
	79	Int_t nphi, Float_t phimin, Float_t phimax,
	80	Float_t rmin, Float_t rmax, Float_t zmax)
	81	: TNamed("Lego Generator",title)
fe4da5cc	82	{
b13db077	83	// specify the angular limits and the size of the rectangular box
	84
	85	fGener = new AliLegoGenerator(ntheta, themin, themax,
	86	nphi, phimin, phimax, rmin, rmax, zmax);
	87
	88	gAlice->SetGenerator(fGener);
	89
	90	Float_t etamin = -TMath::Log(TMath::Tan(TMath::Min((Double_t)themax*kDegrad/2,TMath::Pi()/2-1.e-10)));
	91	Float_t etamax = -TMath::Log(TMath::Tan(TMath::Max((Double_t)themin*kDegrad/2, 1.e-10)));
	92
	93	fHistRadl = new TH2F("hradl","Radiation length map",
	94	nphi,phimin,phimax,ntheta,themin,themax);
	95	fHistAbso = new TH2F("habso","Interaction length map",
	96	nphi,phimin,phimax,ntheta,themin,themax);
	97	fHistGcm2 = new TH2F("hgcm2","g/cm2 length map",
	98	nphi,phimin,phimax,ntheta,themin,themax);
	99	fHistReta = new TH2F("hetar","Radiation length vs. eta",
	100	nphi,phimin,phimax,ntheta,etamin,etamax);
	101
fe4da5cc	102	}
	103
	104	//___________________________________________
	105	AliLego::~AliLego()
	106	{
	107	delete fHistRadl;
	108	delete fHistAbso;
	109	delete fHistGcm2;
	110	delete fHistReta;
	111	}
	112
b13db077	113
	114	//___________________________________________
	115	void AliLego::Run()
	116	{
	117	// loop on phi,theta bins
	118	gMC->InitLego();
	119	Float_t thed, phid, eta;
	120	for (Int_t i=0; i<=fGener->Nphi()*fGener->Ntheta(); ++i) {
	121	// --- Set to 0 radiation length, absorption length and g/cm2 ---
	122	fTotRadl = 0;
	123	fTotAbso = 0;
	124	fTotGcm2 = 0;
	125
	126	gVMC->ProcessEvent();
	127
	128	thed = fGener->CurTheta()*kRaddeg;
	129	phid = fGener->CurPhi()*kRaddeg;
	130	eta = -TMath::Log(TMath::Tan(TMath::Max(
	131	TMath::Min((Double_t)(fGener->CurTheta())/2,
	132	TMath::Pi()/2-1.e-10),1.e-10)));
	133
	134	fHistRadl->Fill(phid,thed,fTotRadl);
	135	fHistAbso->Fill(phid,thed,fTotAbso);
	136	fHistGcm2->Fill(phid,thed,fTotGcm2);
	137	fHistReta->Fill(phid,eta,fTotRadl);
	138	gAlice->FinishEvent();
	139	}
	140	// store histograms in current Root file
	141	fHistRadl->Write();
	142	fHistAbso->Write();
	143	fHistGcm2->Write();
	144	fHistReta->Write();
	145	}
	146
	147	//___________________________________________
	148	void AliLego::StepManager()
	149	{
	150	// called from AliRun::Stepmanager from gustep.
	151	// Accumulate the 3 parameters step by step
	152
	153	static Float_t t;
	154	Float_t a,z,dens,radl,absl;
	155	Int_t i;
	156
	157	Float_t step = gMC->TrackStep();
	158
	159	Float_t vect[3], dir[3];
	160	TLorentzVector pos, mom;
	161
	162	gMC->TrackPosition(pos);
	163	gMC->TrackMomentum(mom);
	164	gMC->CurrentMaterial(a,z,dens,radl,absl);
	165
	166	if (z < 1) return;
	167
	168	// --- See if we have to stop now
	169	if (TMath::Abs(pos[2]) > fGener->ZMax() \|\|
	170	pos[0]pos[0] +pos[1]pos[1] > fGener->RadMax()*fGener->RadMax()) {
	171	if (gMC->TrackLength()) {
	172	// Not the first step, add past contribution
	173	fTotAbso += t/absl;
	174	fTotRadl += t/radl;
	175	fTotGcm2 += t*dens;
	176	}
177	gMC->StopTrack();
178	return;
179	}
180
181	// --- See how long we have to go
182	for(i=0;i<3;++i) {
183	vect[i]=pos[i];
184	dir[i]=mom[i];
185	}
186
187	t = fGener->PropagateCylinder(vect,dir,fGener->RadMax(),fGener->ZMax());
188
189	if(step) {
190	fTotAbso += step/absl;
191	fTotRadl += step/radl;
192	fTotGcm2 += step*dens;
193	}
194	}
195
196	ClassImp(AliLegoGenerator)
197
198	//___________________________________________
199	AliLegoGenerator::AliLegoGenerator(Int_t ntheta, Float_t themin,
200	Float_t themax, Int_t nphi,
201	Float_t phimin, Float_t phimax,
202	Float_t rmin, Float_t rmax, Float_t zmax) :
203	AliGenerator(0), fRadMin(rmin), fRadMax(rmax), fZMax(zmax), fNtheta(ntheta),
204	fNphi(nphi), fThetaBin(ntheta), fPhiBin(-1), fCurTheta(0), fCurPhi(0)
205
206	{
207	SetPhiRange(phimin,phimax);
208	SetThetaRange(themin,themax);
209	SetName("Lego");
210	}
211
212
fe4da5cc	213	//___________________________________________
b13db077	214	void AliLegoGenerator::Generate()
fe4da5cc	215	{
	216	// Create a geantino with kinematics corresponding to the current
	217	// bins in theta and phi.
	218
1578254f	219	//
	220	// Rootinos are 0
	221	const Int_t mpart = 0;
fe4da5cc	222	Float_t orig[3], pmom[3];
	223	Float_t t, cost, sint, cosp, sinp;
	224
b13db077	225	// Prepare for next step
	226	if(fThetaBin>=fNtheta-1)
	227	if(fPhiBin>=fNphi-1) {
	228	Warning("Generate","End of Lego Generation");
	229	return;
	230	} else {
	231	fPhiBin++;
	232	printf("Generating rays in phi bin:%d\n",fPhiBin);
	233	fThetaBin=0;
	234	} else fThetaBin++;
fe4da5cc	235
b13db077	236	fCurTheta = (fThetaMin+(fThetaBin+0.5)*(fThetaMax-fThetaMin)/fNtheta);
b13db077	237	fCurPhi = (fPhiMin+(fPhiBin+0.5)*(fPhiMax-fPhiMin)/fNphi);
fe4da5cc	238	cost = TMath::Cos(fCurTheta);
	239	sint = TMath::Sin(fCurTheta);
	240	cosp = TMath::Cos(fCurPhi);
	241	sinp = TMath::Sin(fCurPhi);
b13db077	242
fe4da5cc	243	pmom[0] = cosp*sint;
	244	pmom[1] = sinp*sint;
	245	pmom[2] = cost;
b13db077	246
b13db077	247	// --- Where to start
fe4da5cc	248	orig[0] = orig[1] = orig[2] = 0;
	249	Float_t dalicz = 3000;
	250	if (fRadMin > 0) {
b13db077	251	t = PropagateCylinder(orig,pmom,fRadMin,dalicz);
	252	orig[0] = pmom[0]*t;
	253	orig[1] = pmom[1]*t;
	254	orig[2] = pmom[2]*t;
	255	if (TMath::Abs(orig[2]) > fZMax) return;
fe4da5cc	256	}
b13db077	257
fe4da5cc	258	Float_t polar[3]={0.,0.,0.};
	259	Int_t ntr;
	260	gAlice->SetTrack(1, 0, mpart, pmom, orig, polar, 0, "LEGO ray", ntr);
fe4da5cc	261
	262	}
	263
	264	//___________________________________________
b13db077	265	Float_t AliLegoGenerator::PropagateCylinder(Float_t x, Float_t v, Float_t r, Float_t z)
fe4da5cc	266	{
	267	// Propagate to cylinder from inside
	268
	269	Double_t hnorm, sz, t, t1, t2, t3, sr;
	270	Double_t d[3];
	271	const Float_t kSmall = 1e-8;
	272	const Float_t kSmall2 = kSmall*kSmall;
	273
	274	// ---> Find intesection with Z planes
	275	d[0] = v[0];
	276	d[1] = v[1];
	277	d[2] = v[2];
	278	hnorm = TMath::Sqrt(1/(d[0]d[0]+d[1]d[1]+d[2]*d[2]));
	279	d[0] *= hnorm;
	280	d[1] *= hnorm;
	281	d[2] *= hnorm;
	282	if (d[2] > kSmall) sz = (z-x[2])/d[2];
	283	else if (d[2] < -kSmall) sz = -(z+x[2])/d[2];
	284	else sz = 1.e10; // ---> Direction parallel to X-Y, no intersection
	285
	286	// ---> Intersection with cylinders
	287	// Intersection point (x,y,z)
	288	// (x,y,z) is on track : x=X(1)+t*D(1)
	289	// y=X(2)+t*D(2)
	290	// z=X(3)+t*D(3)
	291	// (x,y,z) is on cylinder : x2 + y2 = R**2
	292	//
	293	// (D(1)2+D(2)2)t*2
	294	// +2.(X(1)D(1)+X(2)D(2))t
	295	// +X(1)2+X(2)2-R**2=0
	296	// ---> Solve second degree equation
	297	t1 = d[0]d[0] + d[1]d[1];
	298	if (t1 <= kSmall2) {
	299	t = sz; // ---> Track parallel to the z-axis, take distance to planes
	300	} else {
	301	t2 = x[0]d[0] + x[1]d[1];
	302	t3 = x[0]x[0] + x[1]x[1];
	303	// ---> It should be positive, but there may be numerical problems
	304	sr = (t2 +TMath::Sqrt(TMath::Max(t2t2-(t3-rr)*t1,0.)))/t1;
	305	// ---> Find minimum distance between planes and cylinder
	306	t = TMath::Min(sz,sr);
	307	}
	308	return t;
	309	}
	310