Adding new macro to visualize the QA results - A couple of modifications in the 2D...
[u/mrichter/AliRoot.git] / FMD / AliFMDBaseDigitizer.cxx
CommitLineData
02a27b50 1/**************************************************************************
2 * Copyright(c) 2004, 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/* $Id$ */
16/** @file AliFMDBaseDigitizer.cxx
17 @author Christian Holm Christensen <cholm@nbi.dk>
18 @date Mon Mar 27 12:38:26 2006
19 @brief FMD Digitizers implementation
20 @ingroup FMD_sim
21*/
22//////////////////////////////////////////////////////////////////////////////
23//
24// This class contains the procedures simulation ADC signal for the
25// Forward Multiplicity detector : Hits->Digits and Hits->SDigits
26//
27// Digits consists of
28// - Detector #
29// - Ring ID
30// - Sector #
31// - Strip #
32// - ADC count in this channel
33//
34// Digits consists of
35// - Detector #
36// - Ring ID
37// - Sector #
38// - Strip #
39// - Total energy deposited in the strip
40// - ADC count in this channel
41//
42// As the Digits and SDigits have so much in common, the classes
43// AliFMDDigitizer and AliFMDSDigitizer are implemented via a base
44// class AliFMDBaseDigitizer.
45//
46// +---------------------+
47// | AliFMDBaseDigitizer |
48// +---------------------+
49// ^
50// |
51// +----------+---------+
52// | |
53// +-----------------+ +------------------+
54// | AliFMDDigitizer | | AliFMDSDigitizer |
55// +-----------------+ +------------------+
56//
57// These classes has several paramters:
58//
59// fPedestal
60// fPedestalWidth
61// (Only AliFMDDigitizer)
62// Mean and width of the pedestal. The pedestal is simulated
63// by a Guassian, but derived classes my override MakePedestal
64// to simulate it differently (or pick it up from a database).
65//
66// fVA1MipRange
67// The dymamic MIP range of the VA1_ALICE pre-amplifier chip
68//
69// fAltroChannelSize
70// The largest number plus one that can be stored in one
71// channel in one time step in the ALTRO ADC chip.
72//
73// fSampleRate
74// How many times the ALTRO ADC chip samples the VA1_ALICE
75// pre-amplifier signal. The VA1_ALICE chip is read-out at
76// 10MHz, while it's possible to drive the ALTRO chip at
77// 25MHz. That means, that the ALTRO chip can have time to
78// sample each VA1_ALICE signal up to 2 times. Although it's
79// not certain this feature will be used in the production,
80// we'd like have the option, and so it should be reflected in
81// the code.
82//
83//
84// The shaping function of the VA1_ALICE is generally given by
85//
86// f(x) = A(1 - exp(-Bx))
87//
88// where A is the total charge collected in the pre-amp., and B is a
89// paramter that depends on the shaping time of the VA1_ALICE circut.
90//
91// When simulating the shaping function of the VA1_ALICe
92// pre-amp. chip, we have to take into account, that the shaping
93// function depends on the previous value of read from the pre-amp.
94//
95// That results in the following algorithm:
96//
97// last = 0;
98// FOR charge IN pre-amp. charge train DO
99// IF last < charge THEN
100// f(t) = (charge - last) * (1 - exp(-B * t)) + last
101// ELSE
102// f(t) = (last - charge) * exp(-B * t) + charge)
103// ENDIF
104// FOR i IN # samples DO
105// adc_i = f(i / (# samples))
106// DONE
107// last = charge
108// DONE
109//
110// Here,
111//
112// pre-amp. charge train
113// is a series of 128 charges read from the VA1_ALICE chip
114//
115// # samples
116// is the number of times the ALTRO ADC samples each of the 128
117// charges from the pre-amp.
118//
119// Where Q is the total charge collected by the VA1_ALICE
120// pre-amplifier. Q is then given by
121//
122// E S
123// Q = - -
124// e R
125//
126// where E is the total energy deposited in a silicon strip, R is the
127// dynamic range of the VA1_ALICE pre-amp (fVA1MipRange), e is the
128// energy deposited by a single MIP, and S ALTRO channel size in each
129// time step (fAltroChannelSize).
130//
131// The energy deposited per MIP is given by
132//
133// e = M * rho * w
134//
135// where M is the universal number 1.664, rho is the density of
136// silicon, and w is the depth of the silicon sensor.
137//
138// The final ADC count is given by
139//
140// C' = C + P
141//
142// where P is the (randomized) pedestal (see MakePedestal)
143//
144// This class uses the class template AliFMDMap<Type> to make an
145// internal cache of the energy deposted of the hits. The class
146// template is instantasized as
147//
148// typedef AliFMDMap<std::pair<Float_t, UShort_t> > AliFMDEdepMap;
149//
150// The first member of the values is the summed energy deposition in a
151// given strip, while the second member of the values is the number of
152// hits in a given strip. Using the second member, it's possible to
153// do some checks on just how many times a strip got hit, and what
154// kind of error we get in our reconstructed hits. Note, that this
155// information is currently not written to the digits tree. I think a
156// QA (Quality Assurance) digit tree is better suited for that task.
157// However, the information is there to be used in the future.
158//
159//
160// Latest changes by Christian Holm Christensen
161//
162//////////////////////////////////////////////////////////////////////////////
163
164// /1
165// | A(-1 + B + exp(-B))
166// | f(x) dx = ------------------- = 1
167// | B
168// / 0
169//
170// and B is the a parameter defined by the shaping time (fShapingTime).
171//
172// Solving the above equation, for A gives
173//
174// B
175// A = ----------------
176// -1 + B + exp(-B)
177//
178// So, if we define the function g: [0,1] -> [0:1] by
179//
180// / v
181// | Bu + exp(-Bu) - Bv - exp(-Bv)
182// g(u,v) = | f(x) dx = -A -----------------------------
183// | B
184// / u
185//
186// we can evaluate the ALTRO sample of the VA1_ALICE pre-amp between
187// any two times (u, v), by
188//
189//
190// B Bu + exp(-Bu) - Bv - exp(-Bv)
191// C = Q g(u,v) = - Q ---------------- -----------------------------
192// -1 + B + exp(-B) B
193//
194// Bu + exp(-Bu) - Bv - exp(-Bv)
195// = - Q -----------------------------
196// -1 + B + exp(-B)
197//
198
090026bf 199#include <TMath.h>
02a27b50 200#include <TTree.h> // ROOT_TTree
201//#include <TRandom.h> // ROOT_TRandom
f95a63c4 202// #include <AliLog.h> // ALILOG_H
203#include "AliFMDDebug.h" // Better debug macros
02a27b50 204#include "AliFMDBaseDigitizer.h" // ALIFMDDIGITIZER_H
205#include "AliFMD.h" // ALIFMD_H
206#include "AliFMDGeometry.h" // ALIFMDGEOMETRY_H
207#include "AliFMDDetector.h" // ALIFMDDETECTOR_H
208#include "AliFMDRing.h" // ALIFMDRING_H
209#include "AliFMDHit.h" // ALIFMDHIT_H
6169f936 210// #include "AliFMDDigit.h" // ALIFMDDIGIT_H
02a27b50 211#include "AliFMDParameters.h" // ALIFMDPARAMETERS_H
6169f936 212// #include <AliRunDigitizer.h> // ALIRUNDIGITIZER_H
02a27b50 213//#include <AliRun.h> // ALIRUN_H
214#include <AliLoader.h> // ALILOADER_H
215#include <AliRunLoader.h> // ALIRUNLOADER_H
216
217//====================================================================
218ClassImp(AliFMDBaseDigitizer)
219#if 0
220 ; // This is here to keep Emacs for indenting the next line
221#endif
222
223//____________________________________________________________________
224AliFMDBaseDigitizer::AliFMDBaseDigitizer()
b5ee4425 225 : fRunLoader(0),
226 fEdep(AliFMDMap::kMaxDetectors,
227 AliFMDMap::kMaxRings,
228 AliFMDMap::kMaxSectors,
229 AliFMDMap::kMaxStrips),
2aeec17d 230 fShapingTime(6)
02a27b50 231{
232 // Default ctor - don't use it
233}
234
235//____________________________________________________________________
236AliFMDBaseDigitizer::AliFMDBaseDigitizer(AliRunDigitizer* manager)
237 : AliDigitizer(manager, "AliFMDBaseDigitizer", "FMD Digitizer base class"),
238 fRunLoader(0),
239 fEdep(AliFMDMap::kMaxDetectors,
240 AliFMDMap::kMaxRings,
241 AliFMDMap::kMaxSectors,
b5ee4425 242 AliFMDMap::kMaxStrips),
2aeec17d 243 fShapingTime(6)
02a27b50 244{
245 // Normal CTOR
f95a63c4 246 AliFMDDebug(1, (" processed"));
02a27b50 247 SetShapingTime();
248}
249
250//____________________________________________________________________
251AliFMDBaseDigitizer::AliFMDBaseDigitizer(const Char_t* name,
252 const Char_t* title)
253 : AliDigitizer(name, title),
254 fRunLoader(0),
255 fEdep(AliFMDMap::kMaxDetectors,
256 AliFMDMap::kMaxRings,
257 AliFMDMap::kMaxSectors,
322be683 258 AliFMDMap::kMaxStrips),
259 fShapingTime(6)
02a27b50 260{
261 // Normal CTOR
f95a63c4 262 AliFMDDebug(1, (" processed"));
02a27b50 263 SetShapingTime();
264}
265
266//____________________________________________________________________
267AliFMDBaseDigitizer::~AliFMDBaseDigitizer()
268{
269 // Destructor
270}
271
272//____________________________________________________________________
273Bool_t
274AliFMDBaseDigitizer::Init()
275{
276 // Initialization
277 AliFMDParameters::Instance()->Init();
8b26caab 278 if (AliLog::GetDebugLevel("FMD","") >= 10)
279 AliFMDParameters::Instance()->Print("ALL");
02a27b50 280 return kTRUE;
281}
282
283
284//____________________________________________________________________
285UShort_t
286AliFMDBaseDigitizer::MakePedestal(UShort_t,
287 Char_t,
288 UShort_t,
289 UShort_t) const
290{
291 // Make a pedestal
292 return 0;
293}
294
295//____________________________________________________________________
296void
297AliFMDBaseDigitizer::SumContributions(AliFMD* fmd)
298{
299 // Sum energy deposited contributions from each hit in a cache
300 // (fEdep).
301 if (!fRunLoader)
302 Fatal("SumContributions", "no run loader");
303
304 // Clear array of deposited energies
305 fEdep.Reset();
306
307 // Get the FMD loader
308 AliLoader* inFMD = fRunLoader->GetLoader("FMDLoader");
309 // And load the hits
310 inFMD->LoadHits("READ");
311
312 // Get the tree of hits
313 TTree* hitsTree = inFMD->TreeH();
314 if (!hitsTree) {
315 // Try again
316 inFMD->LoadHits("READ");
317 hitsTree = inFMD->TreeH();
318 }
319
320 // Get the FMD branch
321 TBranch* hitsBranch = hitsTree->GetBranch("FMD");
322 if (hitsBranch) fmd->SetHitsAddressBranch(hitsBranch);
323 else AliFatal("Branch FMD hit not found");
324
325 // Get a list of hits from the FMD manager
326 TClonesArray *fmdHits = fmd->Hits();
327
328 // Get number of entries in the tree
329 Int_t ntracks = Int_t(hitsTree->GetEntries());
330
331 AliFMDParameters* param = AliFMDParameters::Instance();
332 Int_t read = 0;
333 // Loop over the tracks in the
334 for (Int_t track = 0; track < ntracks; track++) {
335 // Read in entry number `track'
336 read += hitsBranch->GetEntry(track);
337
338 // Get the number of hits
339 Int_t nhits = fmdHits->GetEntries ();
340 for (Int_t hit = 0; hit < nhits; hit++) {
341 // Get the hit number `hit'
342 AliFMDHit* fmdHit =
343 static_cast<AliFMDHit*>(fmdHits->UncheckedAt(hit));
344
345 // Extract parameters
346 UShort_t detector = fmdHit->Detector();
347 Char_t ring = fmdHit->Ring();
348 UShort_t sector = fmdHit->Sector();
349 UShort_t strip = fmdHit->Strip();
350 Float_t edep = fmdHit->Edep();
15b17c89 351 // UShort_t minstrip = param->GetMinStrip(detector, ring, sector, strip);
352 // UShort_t maxstrip = param->GetMaxStrip(detector, ring, sector, strip);
02a27b50 353 // Check if strip is `dead'
f95a63c4 354 AliFMDDebug(2, ("Hit in FMD%d%c[%2d,%3d]=%f",
355 detector, ring, sector, strip, edep));
02a27b50 356 if (param->IsDead(detector, ring, sector, strip)) {
f95a63c4 357 AliFMDDebug(1, ("FMD%d%c[%2d,%3d] is marked as dead",
02a27b50 358 detector, ring, sector, strip));
359 continue;
360 }
361 // Check if strip is out-side read-out range
15b17c89 362 // if (strip < minstrip || strip > maxstrip) {
f95a63c4 363 // AliFMDDebug(5, ("FMD%d%c[%2d,%3d] is outside range [%3d,%3d]",
15b17c89 364 // detector,ring,sector,strip,minstrip,maxstrip));
365 // continue;
366 // }
02a27b50 367
368 // Give warning in case of double hit
369 if (fEdep(detector, ring, sector, strip).fEdep != 0)
f95a63c4 370 AliFMDDebug(5, ("Double hit in %d%c(%d,%d)",
02a27b50 371 detector, ring, sector, strip));
372
373 // Sum energy deposition
374 fEdep(detector, ring, sector, strip).fEdep += edep;
375 fEdep(detector, ring, sector, strip).fN += 1;
376 // Add this to the energy deposited for this strip
377 } // hit loop
378 } // track loop
f95a63c4 379 AliFMDDebug(1, ("Size of cache: %d bytes, read %d bytes",
02a27b50 380 sizeof(fEdep), read));
381}
382
383//____________________________________________________________________
384void
385AliFMDBaseDigitizer::DigitizeHits(AliFMD* fmd) const
386{
387 // For the stored energy contributions in the cache (fEdep), convert
388 // the energy signal to ADC counts, and store the created digit in
389 // the digits array (AliFMD::fDigits)
390 //
391 AliFMDGeometry* geometry = AliFMDGeometry::Instance();
392
2aeec17d 393 TArrayI counts(4);
02a27b50 394 for (UShort_t detector=1; detector <= 3; detector++) {
f95a63c4 395 AliFMDDebug(5, ("Processing hits in FMD%d", detector));
02a27b50 396 // Get pointer to subdetector
397 AliFMDDetector* det = geometry->GetDetector(detector);
398 if (!det) continue;
399 for (UShort_t ringi = 0; ringi <= 1; ringi++) {
400 Char_t ring = ringi == 0 ? 'I' : 'O';
f95a63c4 401 AliFMDDebug(5, (" Processing hits in FMD%d%c", detector,ring));
02a27b50 402 // Get pointer to Ring
403 AliFMDRing* r = det->GetRing(ring);
404 if (!r) continue;
405
406 // Get number of sectors
407 UShort_t nSectors = UShort_t(360. / r->GetTheta());
408 // Loop over the number of sectors
409 for (UShort_t sector = 0; sector < nSectors; sector++) {
f95a63c4 410 AliFMDDebug(5, (" Processing hits in FMD%d%c[%2d]",
411 detector,ring,sector));
02a27b50 412 // Get number of strips
413 UShort_t nStrips = r->GetNStrips();
414 // Loop over the stips
415 Float_t last = 0;
416 for (UShort_t strip = 0; strip < nStrips; strip++) {
417 // Reset the counter array to the invalid value -1
418 counts.Reset(-1);
419 // Reset the last `ADC' value when we've get to the end of a
420 // VA1_ALICE channel.
421 if (strip % 128 == 0) last = 0;
422
423 Float_t edep = fEdep(detector, ring, sector, strip).fEdep;
424 ConvertToCount(edep, last, detector, ring, sector, strip, counts);
425 last = edep;
8b26caab 426
427 // The following line was introduced - wrongly - by Peter
428 // Hristov. It _will_ break the digitisation and the
429 // following reconstruction. The behviour of the
430 // digitisation models exactly the front-end as it should
431 // (no matter what memory concuption it may entail). The
432 // check should be on zero suppression, since that's what
433 // models the front-end - if zero suppression is turned on
434 // in the front-end, then we can suppress empty digits -
435 // otherwise we shoud never do that. Note, that the line
436 // affects _both_ normal digitisation and digitisation for
437 // summable digits, since the condition is on the energy
438 // deposition and not on the actual number of counts. If
439 // this line should go anywhere, it should be in the
440 // possible overloaded AliFMDSDigitizer::AddDigit - not
441 // here.
442 //
443 // if (edep<=0) continue;
02a27b50 444 AddDigit(fmd, detector, ring, sector, strip, edep,
445 UShort_t(counts[0]), Short_t(counts[1]),
2aeec17d 446 Short_t(counts[2]), Short_t(counts[3]));
f95a63c4 447 AliFMDDebug(10, (" Adding digit in FMD%d%c[%2d,%3d]=%d",
448 detector,ring,sector,strip,counts[0]));
02a27b50 449#if 0
450 // This checks if the digit created will give the `right'
451 // number of particles when reconstructed, using a naiive
452 // approach. It's here only as a quality check - nothing
453 // else.
454 CheckDigit(digit, fEdep(detector, ring, sector, strip).fN,
455 counts);
456#endif
457 } // Strip
458 } // Sector
459 } // Ring
460 } // Detector
461}
462
463//____________________________________________________________________
464void
465AliFMDBaseDigitizer::ConvertToCount(Float_t edep,
466 Float_t last,
467 UShort_t detector,
468 Char_t ring,
469 UShort_t sector,
470 UShort_t strip,
471 TArrayI& counts) const
472{
473 // Convert the total energy deposited to a (set of) ADC count(s).
474 //
475 // This is done by
476 //
477 // Energy_Deposited ALTRO_Channel_Size
478 // ADC = -------------------------- ------------------- + pedestal
479 // Energy_Deposition_Of_1_MIP VA1_ALICE_MIP_Range
480 //
481 // Energy_Deposited fAltroChannelSize
482 // = --------------------------------- ----------------- + pedestal
483 // 1.664 * Si_Thickness * Si_Density fVA1MipRange
484 //
485 //
486 // = Energy_Deposited * ConversionFactor + pedestal
487 //
488 // However, this is modified by the response function of the
489 // VA1_ALICE pre-amp. chip in case we are doing oversampling of the
490 // VA1_ALICE output.
491 //
492 // In that case, we get N=fSampleRate values of the ADC, and the
493 // `EnergyDeposited' is a function of which sample where are
494 // calculating the ADC for
495 //
496 // ADC_i = f(EnergyDeposited, i/N, Last) * ConversionFactor + pedestal
497 //
498 // where Last is the Energy deposited in the previous strip.
499 //
500 // Here, f is the shaping function of the VA1_ALICE. This is given
501 // by
502 //
503 // | (E - l) * (1 - exp(-B * t) + l if E > l
504 // f(E, t, l) = <
505 // | (l - E) * exp(-B * t) + E otherwise
506 //
507 //
508 // = E + (l - E) * ext(-B * t)
509 //
510 AliFMDParameters* param = AliFMDParameters::Instance();
a9579262 511 Float_t convF = 1./param->GetPulseGain(detector,ring,sector,strip);
512 Int_t ped = MakePedestal(detector,ring,sector,strip);
513 Int_t maxAdc = param->GetAltroChannelSize()-1;
514 if (maxAdc < 0) {
515 AliWarning(Form("Maximum ADC is %d < 0, forcing it to 1023", maxAdc));
516 maxAdc = 1023;
517 }
02a27b50 518 UShort_t rate = param->GetSampleRate(detector,ring,sector,strip);
2aeec17d 519 if (rate < 1 || rate > 4) rate = 1;
02a27b50 520
521 // In case we don't oversample, just return the end value.
522 if (rate == 1) {
a9579262 523 Float_t a = edep * convF + ped;
524 if (a < 0) a = 0;
525 counts[0] = UShort_t(TMath::Min(a, Float_t(maxAdc)));
f95a63c4 526 AliFMDDebug(2, ("FMD%d%c[%2d,%3d]: converting ELoss %f to "
a9579262 527 "ADC %4d (%f,%d)",
528 detector,ring,sector,strip,edep,counts[0],convF,ped));
02a27b50 529 return;
530 }
531
532 // Create a pedestal
533 Float_t b = fShapingTime;
534 for (Ssiz_t i = 0; i < rate; i++) {
2aeec17d 535 Float_t t = Float_t(i) / rate + 1./rate;
a9579262 536 Float_t s = edep + (last - edep) * TMath::Exp(-b * t);
537 Float_t a = Int_t(s * convF + ped);
538 if (a < 0) a = 0;
539 counts[i] = UShort_t(TMath::Min(a, Float_t(maxAdc)));
02a27b50 540 }
541}
542
543
544
545//____________________________________________________________________
546//
547// EOF
548//
549
550
551
552