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[u/mrichter/AliRoot.git] / EVGEN / AliGenAfterBurnerFlow.cxx
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ac3faee4 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 **************************************************************************/
4966b266 15
ac3faee4 16/* $Id$ */
17
18///////////////////////////////////////////////////////////////////////////////
4966b266 19//
20// AliGenAfterBurnerFlow is a After Burner event generator applying flow.
21// The generator changes Phi coordinate of the particle momentum.
22// Flow (directed and elliptical) can be defined on particle type level
23//
4966b266 24// Author:
f9f62d8e 25// Sylwester Radomski, 2002
26// Martin Poghosyan, 2008
27// Constantin Loizides, 2010
ac3faee4 28//////////////////////////////////////////////////////////////////////////////
4966b266 29
b2ab503d 30#include <Riostream.h>
f9f62d8e 31#include <TParticle.h>
32#include <TLorentzVector.h>
33#include <TList.h>
34#include <TRandom.h>
4966b266 35#include "AliStack.h"
36#include "AliGenAfterBurnerFlow.h"
37#include "AliGenCocktailAfterBurner.h"
f9f62d8e 38#include "AliMC.h"
cc41459d 39#include "AliCollisionGeometry.h"
40#include "AliGenCocktailEntry.h"
f9f62d8e 41
cc41459d 42
4966b266 43ClassImp(AliGenAfterBurnerFlow)
44
4966b266 45
f9f62d8e 46AliGenAfterBurnerFlow::AliGenAfterBurnerFlow():AliGenerator(),
47 fReactionPlane(0),
48 fHow(0),
49 fCounter(0),
50 fStack(0)
1c56e311 51{
f9f62d8e 52 //
53 // Default Construction
54 InitPrimaries();
55 SetNpParams();
4966b266 56}
57
f9f62d8e 58AliGenAfterBurnerFlow::AliGenAfterBurnerFlow(Float_t reactionPlane):AliGenerator(),
59 fReactionPlane(TMath::Pi()*reactionPlane/180.),
60 fHow(1),
61 fCounter(0),
62 fStack(0)
1c56e311 63{
cc41459d 64 // reactionPlane - Reaction Plane Angle given in Deg [0-360]
65 // but stored and applied in radiants (standard for TParticle & AliCollisionGeometry)
66
f9f62d8e 67 InitPrimaries();
68 SetNpParams();
4966b266 69}
70
71////////////////////////////////////////////////////////////////////////////////////////////////////
72
f9f62d8e 73AliGenAfterBurnerFlow::~AliGenAfterBurnerFlow()
74{
75 // def. dest.
4966b266 76}
77
f9f62d8e 78void AliGenAfterBurnerFlow::SetDirectedSimple(Int_t pdg, Float_t v1)
79{
7e4131fc 80 //
81 // Set Directed Flow
82 // The same directed flow is applied to all specified particles
83 // independently on transverse momentum or rapidity
84 //
85 // PDG - particle type to apply directed flow
86 // if (PDG == 0) use as default
87 //
88
89 SetFlowParameters(pdg, 1, 0, v1, 0, 0, 0);
90}
91
92////////////////////////////////////////////////////////////////////////////////////////////////////
93
f9f62d8e 94void AliGenAfterBurnerFlow::SetDirectedParam(Int_t pdg, Float_t v11, Float_t v12,
95 Float_t v13, Float_t v14)
96{
7e4131fc 97 //
98 // Set Directed Flow
99 // Directed flow is parameterised as follows
4966b266 100 //
f9f62d8e 101 // V1(Pt,Y) = (V11 + V12*Pt) * sign(Y) * (V13 + V14 * abs(Y)^3)
4966b266 102 //
103 // where sign = 1 for Y > 0 and -1 for Y < 0
104 //
105 // Defaults values
106 // v12 = v14 = 0
107 // v13 = 1
7e4131fc 108 //
109 // PDG - particle type to apply directed flow
110 // if (PDG == 0) use as default
111 //
112
113 SetFlowParameters(pdg, 1, 1, v11, v12, v13, v14);
4966b266 114}
115
116////////////////////////////////////////////////////////////////////////////////////////////////////
117
f9f62d8e 118void AliGenAfterBurnerFlow::SetEllipticSimple(Int_t pdg, Float_t v2)
119{
4966b266 120 //
7e4131fc 121 // Set Elliptic Flow
122 // The same Elliptic flow is applied to all specified particles
123 // independently on transverse momentum or rapidity
4966b266 124 //
7e4131fc 125 // PDG - particle type to apply directed flow
126 // if (PDG == 0) use as default
4966b266 127 //
7e4131fc 128 // V2 - flow coefficient
129 //
130 // NOTE: for starting playing with FLOW
131 // start with this function and values 0.05 - 0.1
4966b266 132 //
133
7e4131fc 134 SetFlowParameters(pdg, 2, 0, v2, 0, 0, 0);
4966b266 135}
136
137////////////////////////////////////////////////////////////////////////////////////////////////////
138
f9f62d8e 139void AliGenAfterBurnerFlow::SetEllipticParam(Int_t pdg,
140 Float_t v00, Float_t v10, Float_t v11,
141 Float_t v22)
142{
143 //
144 // Set Elliptic Flow
145 //
146 // Elliptic flow is parametrised to reproduce
147 // V2 of Pions at RHIC energies and is given by:
148 //
149 // V2 = (v00 + v10*pt + v11*pt^2) * exp (-v22 * y^2) and zero if V2<0.
150 //
151
152 SetFlowParameters(pdg, 2, 3, v00, v10, v11, v22);
153}
154
155void AliGenAfterBurnerFlow::SetEllipticParamPion(Int_t pdg, Float_t v21,
156 Float_t pTmax, Float_t v22)
157{
7e4131fc 158 //
159 // Set Elliptic Flow
160 //
161 // Elliptic flow is parametrised to reproduce
162 // V2 of Pions at RHIC energies and is given by:
4966b266 163 //
7e4131fc 164 // V2 = v21 * (pT/pTMax ) * exp (-v22 * y^2) where pT <= pTmax
f9f62d8e 165 // v21 * exp (-v22 * y^2) where pT > pTmax
4966b266 166 //
7e4131fc 167 // v21 - value at saturation
168 // pTmax - saturation transverse momentum
f9f62d8e 169 // v22 - rapidity decreasing
4966b266 170 //
171
7e4131fc 172 SetFlowParameters(pdg, 2, 1, v21, pTmax, v22, 0);
4966b266 173}
174
175////////////////////////////////////////////////////////////////////////////////////////////////////
176
f9f62d8e 177void AliGenAfterBurnerFlow::SetEllipticParamOld(Int_t pdg, Float_t v21, Float_t v22, Float_t v23)
178{
7e4131fc 179 //
180 // Set Elliptic Flow
4966b266 181 //
7e4131fc 182 // Elliptic flow is parameterised using
183 // old MevSim parameterisation
184 //
185 // V2 = (V21 + V22 pT^2) * exp (-v22 * y^2)
4966b266 186 //
187
7e4131fc 188 SetFlowParameters(pdg, 2, 2, v21, v22, v23, 0);
4966b266 189}
190
191////////////////////////////////////////////////////////////////////////////////////////////////////
192
f9f62d8e 193void AliGenAfterBurnerFlow::SetNpParams(Int_t order, Float_t p0, Float_t p1, Float_t p2, Float_t p3)
194{
195 //
196 // Set npart parameterization.
197 //
198
199 fNpParams[0] = order;
200 fNpParams[1] = p0;
201 fNpParams[2] = p1;
202 fNpParams[3] = p2;
203 fNpParams[4] = p3;
204}
205
206////////////////////////////////////////////////////////////////////////////////////////////////////
207
208void AliGenAfterBurnerFlow::SetFlowParameters(Int_t pdg, Int_t order, Int_t type,
209 Float_t v1, Float_t v2,Float_t v3,Float_t v4)
210{
4966b266 211 //
212 // private function
213 //
f9f62d8e 214
215 if(TMath::Abs(pdg)>fgkPDG){
216 Error("AliAfterBurnerFlow","Overflow");
217 return;
218 }
219 fIsPrim[TMath::Abs(pdg)]=kTRUE;
4966b266 220
221 Int_t index = 0;
7e4131fc 222 Bool_t newEntry = kTRUE;
4966b266 223
224 // Defaults
4966b266 225 if (pdg == 0) {
0af12c00 226 index = fgkN - order;
7e4131fc 227 newEntry = kFALSE;
4966b266 228 }
229
230 // try to find existing entry
231 for (Int_t i=0; i<fCounter; i++) {
232 if (pdg == (Int_t)fParams[i][0] &&
233 order == (Int_t)fParams[i][1]) {
234
235 index = i;
7e4131fc 236 newEntry = kFALSE;
4966b266 237 }
238 }
239
240 // check fCounter
241
0af12c00 242 if (newEntry && (fCounter > fgkN-3)) {
4966b266 243 Error("AliAfterBurnerFlow","Overflow");
244 return;
245 }
246
247 if (newEntry) {
248 index = fCounter;
249 fCounter++;
250 }
251
252 // Set new particle type
253
254 fParams[index][0] = pdg;
255 fParams[index][1] = order;
7e4131fc 256 fParams[index][2] = type;
257 fParams[index][3] = v1;
258 fParams[index][4] = v2;
259 fParams[index][5] = v3;
260 fParams[index][6] = v4;
4966b266 261}
262
263////////////////////////////////////////////////////////////////////////////////////////////////////
264
f9f62d8e 265void AliGenAfterBurnerFlow::Init()
266{
4966b266 267 //
268 // Standard AliGenerator Initializer
269 //
270
f9f62d8e 271 if(fHow == 0) { Info("AliGenAfterBurnerFlow", "Using the Hijing R.P. Angle event by event "); }
272 else if(fHow == 1){ Info("AliGenAfterBurnerFlow", "Using a fixed R.P. Angle for every event ") ; }
273 else { Info("AliGenAfterBurnerFlow",
274 "Using a random R.P. Angle event by event ( ! not the same used by Hijing ! ) "); }
4966b266 275}
276
277////////////////////////////////////////////////////////////////////////////////////////////////////
278
f9f62d8e 279Float_t AliGenAfterBurnerFlow::GetCoefficient(Int_t pdg, Int_t n, Float_t Pt, Float_t Y) const
280{
4966b266 281 //
282 // private function
283 // Return Flow Coefficient for a given particle type flow order
284 // and particle momentum (Pt, Y)
285 //
286
f9f62d8e 287 Int_t index = fgkN - n; // default index (for all pdg)
4966b266 288 Float_t v = 0;
289
290 // try to find specific parametrs
291
292 for (Int_t i=0; i<fCounter; i++) {
4966b266 293 if ((Int_t)fParams[i][0] == pdg &&
294 (Int_t)fParams[i][1] == n) {
295
296 index = i;
297 break;
298 }
299 }
300
301 // calculate v
302
7e4131fc 303 Int_t type = (Int_t)fParams[index][2];
304
4966b266 305 if ((Int_t)fParams[index][1] == 1) { // Directed
7e4131fc 306
307 if (type == 0 )
308 v = fParams[index][3];
309 else
310 v = (fParams[index][3] + fParams[index][4] * Pt) * TMath::Sign((Float_t)1.,Y) *
311 (fParams[index][5] + fParams[index][6] * TMath::Abs(Y*Y*Y) );
4966b266 312
313 } else { // Elliptic
314
7e4131fc 315 if (type == 0) v = fParams[index][3];
316
317 // Pion parameterisation
7e4131fc 318 if (type == 1) {
319 if (Pt < fParams[index][4])
320 v = fParams[index][3] * (Pt / fParams[index][4]) ;
321 else
322 v = fParams[index][3];
323
324 v *= TMath::Exp( - fParams[index][5] * Y * Y);
325 }
326
327 // Old parameterisation
7e4131fc 328 if (type == 2)
329 v = (fParams[index][3] + fParams[index][4] * Pt * Pt) *
330 TMath::Exp( - fParams[index][5] * Y * Y);
f9f62d8e 331
332 // New v2 parameterisation
333 if (type == 3) {
334 v = (fParams[index][3] + fParams[index][4] *Pt + fParams[index][5] *Pt*Pt) *
335 TMath::Exp( - fParams[index][6] * Y*Y);
336 if (v<0)
337 v = 0;
338 }
4966b266 339 }
340
341 return v;
342}
343
344////////////////////////////////////////////////////////////////////////////////////////////////////
345
f9f62d8e 346Float_t AliGenAfterBurnerFlow::GetNpNorm(Int_t npart)
347{
348 //
349 // Calculate npart norm.
350 //
351
352 if (npart<0)
353 return 1;
354
355 Int_t order = (Int_t)fNpParams[0];
356 if (order<0)
357 return 1;
358
359 Float_t ret = 0;
360 Int_t npp = 1;
361 for (Int_t i=0; i<=order; i++) {
362 ret += npp*fNpParams[i+1];
363 npp *= npart;
364 }
365 return ret;
366}
367
368////////////////////////////////////////////////////////////////////////////////////////////////////
369
370Bool_t AliGenAfterBurnerFlow::IsPrimary(Int_t pdg)
371{
372 if(pdg>fgkPDG) return kFALSE;
373 return fIsPrim[pdg];
374}
375
376////////////////////////////////////////////////////////////////////////////////////////////////////
377
378Double_t CalcAngle(Double_t phi, Double_t phi0, Double_t phiRP, Double_t v2, Double_t v1=0.)
379{
380 Double_t phi1 = phi-(phi+2*v1*TMath::Sin(phi-phiRP)+v2*TMath::Sin(2*(phi-phiRP))-phi0)/
381 (1.+2*v1*TMath::Cos(phi-phiRP)+ 2*v2*TMath::Cos(2*(phi-phiRP)));
382 if(TMath::Abs(phi/phi1-1.)<0.00001) return phi1;
383 return CalcAngle(phi1, phi0, phiRP, v2, v1);
384}
385
386////////////////////////////////////////////////////////////////////////////////////////////////////
387
388void AliGenAfterBurnerFlow::InitPrimaries()
389{
390 for(Int_t i=0; i<fgkPDG; i++) fIsPrim[i]=kFALSE;
391
392 //mesons
393 fIsPrim[211]=kTRUE;
394 fIsPrim[311]=kTRUE;
395 fIsPrim[321]=kTRUE;
396 fIsPrim[411]=kTRUE;
397 fIsPrim[421]=kTRUE;
398 fIsPrim[431]=kTRUE;
399 fIsPrim[511]=kTRUE;
400 fIsPrim[521]=kTRUE;
401 fIsPrim[531]=kTRUE;
402 fIsPrim[541]=kTRUE;
403 fIsPrim[111]=kTRUE;
404 fIsPrim[221]=kTRUE;
405 fIsPrim[331]=kTRUE;
406 fIsPrim[441]=kTRUE;
407 fIsPrim[551]=kTRUE;
408 fIsPrim[130]=kTRUE;
409 fIsPrim[310]=kTRUE;
410 fIsPrim[213]=kTRUE;
411 fIsPrim[313]=kTRUE;
412 fIsPrim[323]=kTRUE;
413 fIsPrim[413]=kTRUE;
414 fIsPrim[423]=kTRUE;
415 fIsPrim[433]=kTRUE;
416 fIsPrim[513]=kTRUE;
417 fIsPrim[523]=kTRUE;
418 fIsPrim[533]=kTRUE;
419 fIsPrim[543]=kTRUE;
420 fIsPrim[113]=kTRUE;
421 fIsPrim[223]=kTRUE;
422 fIsPrim[333]=kTRUE;
423 fIsPrim[443]=kTRUE;
424 fIsPrim[553]=kTRUE;
425
426 //baryons
427 fIsPrim[2112]=kTRUE;
428 fIsPrim[2212]=kTRUE;
429 fIsPrim[3112]=kTRUE;
430 fIsPrim[3122]=kTRUE;
431 fIsPrim[3212]=kTRUE;
432 fIsPrim[3222]=kTRUE;
433 fIsPrim[3312]=kTRUE;
434 fIsPrim[3322]=kTRUE;
435 fIsPrim[4112]=kTRUE;
436 fIsPrim[4122]=kTRUE;
437 fIsPrim[4212]=kTRUE;
438 fIsPrim[4222]=kTRUE;
439 fIsPrim[4132]=kTRUE;
440 fIsPrim[4312]=kTRUE;
441 fIsPrim[4232]=kTRUE;
442 fIsPrim[4322]=kTRUE;
443 fIsPrim[4332]=kTRUE;
444 fIsPrim[5112]=kTRUE;
445 fIsPrim[5122]=kTRUE;
446 fIsPrim[5212]=kTRUE;
447 fIsPrim[5222]=kTRUE;
448 fIsPrim[1114]=kTRUE;
449 fIsPrim[2114]=kTRUE;
450 fIsPrim[2214]=kTRUE;
451 fIsPrim[2224]=kTRUE;
452 fIsPrim[3114]=kTRUE;
453 fIsPrim[3214]=kTRUE;
454 fIsPrim[3224]=kTRUE;
455 fIsPrim[3314]=kTRUE;
456 fIsPrim[3324]=kTRUE;
457 fIsPrim[3334]=kTRUE;
458 fIsPrim[4114]=kTRUE;
459 fIsPrim[4214]=kTRUE;
460 fIsPrim[4224]=kTRUE;
461 fIsPrim[4314]=kTRUE;
462 fIsPrim[4324]=kTRUE;
463 fIsPrim[4334]=kTRUE;
464 fIsPrim[5114]=kTRUE;
465 fIsPrim[5214]=kTRUE;
466 fIsPrim[5224]=kTRUE;
467}
468
469////////////////////////////////////////////////////////////////////////////////////////////////////
470
471void AliGenAfterBurnerFlow::Generate()
472{
4966b266 473 //
474 // AliGenerator generate function doing actual job.
475 // Algorythm:
476 //
f9f62d8e 477 // 1. loop over particles on the stack and choose primaries
478 // 2. calculate delta phi
479 // 3. change phi of primary particle and if it is non-stable
480 // then its daughters' phi and vertex also
4966b266 481 //
f9f62d8e 482 // For more details see :
483 // M.G. Poghosyan
484 // PWG2 meeting on 06.05.2008 and 03.06.2008
485
f9f62d8e 486
487 if (0)
488 for(Int_t ii=0; ii<fCounter;ii++)
489 {
490 printf("%d %f %f %f %f\n",ii,fParams[ii][0],fParams[ii][1],fParams[ii][2],fParams[ii][3]);
491 }
492
4966b266 493 AliGenCocktailAfterBurner *gen;
f9f62d8e 494
4966b266 495 TParticle *particle;
f9f62d8e 496 TParticle *particleM;
4966b266 497 TLorentzVector momentum;
f9f62d8e 498 TLorentzVector vertex;
4966b266 499
500 Int_t pdg;
f9f62d8e 501 Float_t phi;
4966b266 502 Float_t pt, y;
503
504 // Get Stack of the first Generator
f9f62d8e 505 // gen = (AliGenCocktailAfterBurner *)gAlice->Generator();
3e2e3ece 506 gen = (AliGenCocktailAfterBurner *)gAlice->GetMCApp()->Generator();
4966b266 507
cc41459d 508
509 AliGenerator* genHijing = 0 ;
510 AliCollisionGeometry* geom = 0 ;
511 AliGenCocktailEntry* entry = 0 ;
512 TList* fEntries = 0 ;
513
514 TRandom* rand = new TRandom(0) ;
cc41459d 515 for(Int_t ns=0;ns<gen->GetNumberOfEvents();ns++)
516 {
f9f62d8e 517 gen->SetActiveEventNumber(ns) ;
518
519 fStack = gen->GetStack(ns);
520 fEntries = gen->Entries() ;
521
522 TIter next(fEntries) ;
523 Int_t npart = -1;
cc41459d 524
cc41459d 525 if(fHow == 0) // hijing R.P.
526 {
f9f62d8e 527 while((entry = (AliGenCocktailEntry*)next()))
528 {
529 Info("Generate (e)","Using R.P. from HIJING ... ");
530 genHijing = entry->Generator() ;
531 if(genHijing->ProvidesCollisionGeometry())
532 {
533 geom = gen->GetCollisionGeometry(ns) ;
534 fReactionPlane = geom->ReactionPlaneAngle() ;
535 npart = geom->ProjectileParticipants() + geom->TargetParticipants();
536 break;
537 }
538 else
539 {
540 Error("Generate (e)", "NO CollisionGeometry !!! - using fixed R.P. angle = 0. ") ;
541 fReactionPlane = 0. ;
542 }
543 }
cc41459d 544 }
f9f62d8e 545 else if(fHow ==1 ) // fixed R.P.
cc41459d 546 {
f9f62d8e 547 Info("Generate (e)","Using fixed R.P. ...");
cc41459d 548 }
f9f62d8e 549 else
cc41459d 550 {
f9f62d8e 551 Info("Generate (e)","Using random R.P.s ... ");
552 fReactionPlane = 2 * TMath::Pi() * rand->Rndm() ;
cc41459d 553 }
f9f62d8e 554
555 cout << " * Reaction Plane Angle (event " << ns << ") = " << fReactionPlane <<
556 " rad. ( = " << (360*fReactionPlane/(2*TMath::Pi())) << " deg.) Npart = " << npart << "* " << endl ;
cc41459d 557
f9f62d8e 558 Int_t nParticles = fStack->GetNprimary();
559 for (Int_t i=0; i<nParticles; i++)
560 {
561 particle = fStack->Particle(i);
562
563 Int_t iM=particle->GetMother(0);
564 pdg = particle->GetPdgCode();
565
566 //exclude incoming protons in PYTHIA
567 if(particle->GetPdgCode()==21) continue;
568
569 if(TMath::Abs(pdg)>fgkPDG) continue;
570 // is particle primary?
571 if(!fIsPrim[TMath::Abs(pdg)]) continue;
572
573 if(iM>0)
574 {
575 particleM = fStack->Particle(iM);
576 Int_t pdgM = TMath::Abs(particleM->GetPdgCode());
577 // is mother primary?
578 if((TMath::Abs(pdgM)<fgkPDG)&&fIsPrim[TMath::Abs(pdgM)]) continue;
579 }
cc41459d 580
f9f62d8e 581 particle->Momentum(momentum);
582 phi = particle->Phi();
cc41459d 583
f9f62d8e 584 // get Pt, y
585 pt = momentum.Pt() ;
586 y = 10000.;
cc41459d 587
f9f62d8e 588 if(TMath::Abs(momentum.Z()) != TMath::Abs(momentum.T()))
589 y = momentum.Rapidity() ;
590
591 Double_t v1 = GetCoefficient(pdg, 1, pt, y);
592 Double_t v2 = GetCoefficient(pdg, 2, pt, y);
593 Double_t npartnorm = GetNpNorm(npart);
594 v2 *= npartnorm;
cc41459d 595
f9f62d8e 596 //printf("ntup %d %f %f %f %f %f\n ",npart, v1, v2, pt, y, npartnorm);
cc41459d 597
f9f62d8e 598 Double_t phi1 = CalcAngle(phi, phi, fReactionPlane,v2,v1);
cc41459d 599
f9f62d8e 600 Rotate(i, phi1-phi);
601 }
4966b266 602 }
603
7e4131fc 604 Info("Generate","Flow After Burner: DONE");
4966b266 605}
606
607////////////////////////////////////////////////////////////////////////////////////////////////////
608
f9f62d8e 609void AliGenAfterBurnerFlow::Rotate(Int_t i, Double_t phi, Bool_t IsPrim)
610{
611 TParticle* particle = fStack->Particle(i);
612
613 TLorentzVector momentum;
614 particle->Momentum(momentum);
615 momentum.RotateZ(phi);
616 particle->SetMomentum(momentum);
617
618 if(!IsPrim)
619 {
620 TLorentzVector vertex;
621 particle->ProductionVertex(vertex);
622 vertex.RotateZ(phi);
623 particle->SetProductionVertex(vertex);
624 }
625
626 if(particle->GetFirstDaughter()<0) return;
627 for(Int_t iD=particle->GetFirstDaughter(); iD<=particle->GetLastDaughter(); iD++) Rotate(iD, phi, kFALSE);
628
629 return;
630}
631
632