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source: svn/trunk/Utilities/Hector/src/H_BeamParticle.cc@ 314

Last change on this file since 314 was 281, checked in by Xavier Rouby, 16 years ago

new Hector version
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1 /* * * * * * * * * * * * * * * * * * * * * * * * * * * *
2 * *
3* --<--<-- A fast simulator --<--<-- *
4* / --<--<-- of particle --<--<-- *
5* ----HECTOR----< *
6* \ -->-->-- transport through -->-->-- *
7* -->-->-- generic beamlines -->-->-- *
8* *
9* JINST 2:P09005 (2007) *
10* X Rouby, J de Favereau, K Piotrzkowski (CP3) *
11* http://www.fynu.ucl.ac.be/hector.html *
12* *
13* Center for Cosmology, Particle Physics and Phenomenology *
14* Universite catholique de Louvain *
15* Louvain-la-Neuve, Belgium *
16 * *
17 * * * * * * * * * * * * * * * * * * * * * * * * * * * */
18
19/// \file H_BeamParticle.cc
20/// \brief Class aiming at simulating a particle in the LHC beam
21
22// from IP to RP, with emission of a photon of defined energy and Q.
23// Units : angles [rad], distances [m], energies [GeV], c=[1].
24// !!! no comment statement at the end of a #define line !!!
25
26// c++ #includes
27#include <iostream>
28#include <iomanip>
29#include <vector>
30#include <string>
31#include <cmath>
32
33// ROOT #includes
34#include "H_Parameters.h"
35#include "TRandom.h"
36#include "TVectorD.h"
37#ifdef _include_pythia_
38#include "TPythia6.h"
39#endif
40
41// local #includes
42#include "H_OpticalElement.h"
43#include "H_BeamParticle.h"
44#include "H_Drift.h"
45
46using namespace std;
47
48void H_BeamParticle::init() { // for more efficiency, put the objects away from init!
49 mp = MP;
50 qp = QP;
51 fx = 0;
52 fy = 0;
53 thx = 0;
54 thy = 0;
55 fs = 0;
56 energy = BE;
57 hasstopped = false;
58 hasemitted = false;
59 isphysical = true;
60 addPosition(fx,thx,fy,thy,fs);
61 stop_position = new TVectorD(LENGTH_VEC);
62 for (int i=0; i<LENGTH_VEC; i++) (*stop_position)[i] = -1;
63 stop_element = 0;
64}
65
66H_BeamParticle::H_BeamParticle() {
67 init();
68}
69
70H_BeamParticle::H_BeamParticle(const H_BeamParticle& p):
71 mp(p.mp), qp(p.qp), fs(p.fs), fx(p.fx), fy(p.fy), thx(p.thx), thy(p.thy),
72 energy(p.energy), hasstopped(p.hasstopped), hasemitted(p.hasemitted),
73 isphysical(p.isphysical), stop_position(new TVectorD(*(p.stop_position))),
74 stop_element(0), positions(p.positions) {
75 if(p.hasstopped) stop_element = new H_OpticalElement(*(p.stop_element));
76}
77
78H_BeamParticle::H_BeamParticle(const double mass, const double charge) {
79 init();
80 mp = mass;
81 qp = (mass==0) ? 0 : charge;
82 /// rejects particles with mass = 0 and charge != 0
83}
84
85H_BeamParticle& H_BeamParticle::operator=(const H_BeamParticle& p) {
86 if(this==&p) return *this;
87 mp = p.mp;
88 qp = p.qp;
89 fx = p.fx;
90 fy = p.fy;
91 thx = p.thx;
92 thy = p.thy;
93 fs = p.fs;
94 energy = p.energy;
95 hasstopped = p.hasstopped;
96 hasemitted = p.hasemitted;
97 isphysical = p.isphysical;
98 stop_position = new TVectorD(*(p.stop_position));
99 if(p.hasstopped) stop_element = new H_OpticalElement(*(p.stop_element));
100 else stop_element = 0;
101 positions = p.positions;
102 return *this;
103}
104
105const bool H_BeamParticle::stopped(const H_AbstractBeamLine * beamline) {
106 vector<TVectorD>::const_iterator position_i;
107 for(position_i = positions.begin(); position_i < positions.end()-1; position_i++) {
108 const unsigned int pos = position_i-positions.begin();
109 if(beamline->getElement(pos)->getAperture()->getType()!=NONE) {
110 bool has_passed_entrance = beamline->getElement(pos)->isInside((*position_i)[INDEX_X],(*position_i)[INDEX_Y]);
111 bool has_passed_exit = beamline->getElement(pos)->isInside((*(position_i+1))[INDEX_X],(*(position_i+1))[INDEX_Y]);
112 // here we should distinguish between particles passing the input or not.
113 // - particles not passing the input are logically stopped at the input position. period.
114 // - particles passing the input but not the output are stopped somewhere in the element
115 // - particles passing both the input and the output could have been stopped somewhere inside too (less likely)
116 if(!has_passed_entrance) {
117 if(VERBOSE) cout<<"Stopped at the entrance of "<<beamline->getElement(pos)->getName();
118 hasstopped=true;
119 stop_element = const_cast<H_OpticalElement*>(beamline->getElement(pos));
120 *stop_position = *position_i;
121 if(VERBOSE) cout<<" at s = "<<(*stop_position)[4]<<endl;
122 return hasstopped;
123 } else if (!has_passed_exit) {
124 if(VERBOSE) cout<<"Stopped inside "<<beamline->getElement(pos)->getName();
125 hasstopped=true;
126 stop_element = const_cast<H_OpticalElement*>(beamline->getElement(pos));
127 // this should be computed using the element-based method "H_OpticalElement::getHitPosition" (caution : always nonlinear).
128 *stop_position = beamline->getElement(pos)->getHitPosition(*position_i,BE-energy,mp,qp);
129 if(VERBOSE) cout<<" at s = "<<(*stop_position)[4]<<endl;
130 return hasstopped;
131 }
132/*
133 if(!(has_passed_entrance && has_passed_exit)) {
134 if(VERBOSE) cout<<"particle stopped at "<<(beamline->getElement(pos))->getName();
135 if(VERBOSE) cout<<" (s = "<<(*position_i)[4] << ")" << endl;
136 hasstopped=true;
137 stop_element = const_cast<H_OpticalElement*>(beamline->getElement(pos));
138 *stop_position = *position_i;
139 return hasstopped;
140 } // if
141*/
142 } // if
143 } // for
144 return hasstopped;
145}
146
147void H_BeamParticle::addPosition(const double x, const double tx, const double y, const double ty, const double s) {
148 // [x] = [y] = m ; [tx] = [ty] = rad; [s] = m
149 double xys[LENGTH_VEC];
150 xys[INDEX_X]=x;
151 xys[INDEX_TX]=tx;
152 xys[INDEX_Y]=y;
153 xys[INDEX_TY]=ty;
154 xys[INDEX_S]=s;
155
156 TVectorD temp_vec(LENGTH_VEC,xys);
157 positions.push_back(temp_vec);
158}
159
160
161
162void H_BeamParticle::smearPos(const double dx,const double dy, TRandom* r) {
163 // the beam is centered on (fx,fy) at IP
164 fx = r->Gaus(fx,dx);
165 fy = r->Gaus(fy,dy);
166 positions.clear();
167 addPosition(fx,thx,fy,thy,fs);
168 return;
169}
170
171void H_BeamParticle::smearAng(const double tx, const double ty, TRandom* r) {
172 // the beam transverse direction is centered on (thx,thy) at IP
173 thx = r->Gaus(thx,tx);
174 thy = r->Gaus(thy,ty);
175 positions.clear();
176 addPosition(fx,thx,fy,thy,fs);
177 return;
178}
179
180void H_BeamParticle::smearE(const double erre, TRandom* r) {
181 energy = r->Gaus(energy,erre);
182 return;
183}
184
185void H_BeamParticle::smearS(const double errs, TRandom* r) {
186 fs= r->Gaus(fs,errs);
187 positions.clear();
188 addPosition(fx,thx,fy,thy,fs);
189 return;
190}
191
192
193void H_BeamParticle::set4Momentum(const double px, const double py, const double pz, const double ene) {
194 /// @param px, py, pz, ene is \f$ (\vec p , E) [GeV]\f$
195 ///
196 /// Clears the H_BeamParticle::positions vector.
197 positions.clear();
198 if(pz==0) {
199 cout<<" ERROR in H_BeamParticle::set4Momentum : no momentum in the beamline direction !"<<endl;
200 return;
201 }
202 thx = thx + URAD*atan(px/pz);
203 thy = thy + URAD*atan(py/pz);
204 energy = ene;
205 positions.clear();
206 addPosition(fx,thx,fy,thy,fs);
207 return;
208}
209
210void H_BeamParticle::set4Momentum(const TLorentzVector& pmu) {
211 /// @param pmu is the particle 4-momentum \f$ p^\mu \f$
212 ///
213 /// Clears the H_BeamParticle::positions vector.
214 set4Momentum(pmu.Px(), pmu.Py(), pmu.Pz(), pmu.E());
215}
216
217void H_BeamParticle::setE(const double ene) {
218 energy = ene;
219 return;
220}
221
222void H_BeamParticle::setPosition(const double x, const double y, const double tx, const double ty, const double s) {
223 /// @param x, y are the transverse positions in \f$ \mu \f$ m
224 /// @param tx, ty are the angles in \f$ \mu \f$ rad
225 /// @param s is the longitudinal coordinate in m
226 // clear positions and sets the initial one.
227 fx=x;
228 fy=y;
229 thx=tx;
230 thy=ty;
231 fs = s;
232 positions.clear();
233 addPosition(fx,thx,fy,thy,s);
234
235 return;
236}
237
238const H_OpticalElement* H_BeamParticle::getStoppingElement() const{
239 if(hasstopped) return stop_element;
240 else { H_OpticalElement * dummy_el = new H_Drift("",0,0); return dummy_el;}
241}
242
243void H_BeamParticle::emitGamma(const double gee, const double gq2, const double phimin, const double phimax) {
244 /// @param gee = \f$ E_{\gamma} \f$ is the photon energy
245 /// @param gq2 = Q < 0 is virtuality of photon \f$ Q^{2} = E^{2}-\vec{k}^{2} \f$
246 /// @param phimin : lower bound for \f$ phi \f$
247 /// @param phimax : higher bound for \f$ phi \f$
248
249 if(gq2==0) {
250 if(VERBOSE) cout<<"No virtuality : only energy has changed"<<endl;
251 setE(energy-gee);
252 return;
253 }
254
255 double m1 = mp;
256
257 double e1 = energy , e2 = energy - gee; // particle energy : before (1) / after (2)
258
259 double p1 = sqrt(pow(e1,2) - pow(m1,2)), p2 = sqrt(pow(e2,2) - pow(m1,2)); // particle momentum : before (1) / after (2)
260 double q2min = pow(gee,2) - pow(p1+p2,2); // lower bound from kinematics E^2 - (p1 + p2)^2
261 double q2max = -2 * pow(m1*gee/(p1+p2),2) * (1 + (pow(e1,2) + pow(e2,2) -pow(m1,2))/(e1*e2 + p1*p2) );
262 // upper bound from kinematics ; E^2 - (p1-p2)^2; is bad for numerical computations
263
264
265 // if q2min < q2 < q2max is NOT true, there will be mathematical problems (like cos(eta) > 1).
266 // so if q2 > q2max, we force q2 = q2max (-> cos(eta) = 1)
267 // and if q2 < q2min, we force q2 = q2min (-> cos(eta) = 1)
268 // BUT the user knows something was wrong with the value of "H_BeamParticle::isphysical"
269 const double q2 = (gq2 > q2max ) ? q2max : (gq2 < q2min) ? q2min : gq2;
270
271 if( (gq2>q2max) || (gq2<q2min)) {
272 if(VERBOSE) cout<<"<H_BeamParticle> WARNING : Non physical particle ! Q2 (" << q2 << ") and E ("<<gee << ") are not compatible." << endl;
273 isphysical = false;
274 }
275
276 if(hasemitted) { cout<<"<H_BeamParticle> WARNING : particle has already emitted at least one gamma !"<<endl;}
277 hasemitted = true;
278 energy = energy - gee;
279 // gkk is k
280 double gkk = sqrt(pow(gee,2)-q2);
281 // eta is the angle between gamma and initial direction of the gamma-emitting particle
282 // ceta = cos(eta) and seta = sin(eta)
283
284 double ceta = sqrt( pow(mp/p1,2) + 1 ) * sqrt( q2/pow(gkk,2) + 1 ) - q2/(2*p1*gkk);
285 double seta = sqrt(1 - ceta*ceta);
286 // theta is the angle between particle and beam
287 double theta = URAD*atan(seta/(BE/gkk - ceta));
288 double phi = phimin + gRandom->Uniform(phimax-phimin);
289 thx = thx + theta*cos(phi);
290 thy = thy - theta*sin(phi);
291
292 // caution : emitting a photon erases all known positions !
293 positions.clear();
294 addPosition(fx,thx,fy,thy,fs);
295 return;
296}
297
298void H_BeamParticle::doInelastic() {
299#ifdef _include_pythia_
300// if(!gROOT->GetClass("TPythia6")) {
301// gROOT->Reset();
302// gSystem->Load("libPythia6");
303// gSystem->Load("libEG");
304// gSystem->Load("libEGPythia6");
305// }
306
307 TPythia6 gen;
308 // select AB -> AX process
309 gen.SetMSEL(0);
310 gen.SetMSUB(93,1);
311 // no showers/decays
312 gen.SetMSTP(111,0);
313 // no printouts
314 gen.SetMSTP(122,0);
315 gen.SetMSTU(12,0);
316 // generator initialization
317 gen.Initialize("CMS","p","p",14000);
318 // event generation
319 gen.GenerateEvent();
320 // list particles
321// gen.Pylist(1);
322 thx = thx + URAD*atan(gen.GetP(5,1)/gen.GetP(5,3));
323 thy = thy + URAD*atan(gen.GetP(5,2)/gen.GetP(5,3));
324 energy = gen.GetP(5,4);
325 positions.clear();
326 addPosition(fx,thx,fy,thy,fs);
327#endif
328 return;
329}
330
331std::ostream& operator<< (std::ostream& os, const H_BeamParticle& p) {
332 os << " M = " << p.getM() << "GeV ";
333 os << " Q = " << p.getQ() << "e";
334 os << " fx = " << p.getX() << "m ";
335 os << " fy = " << p.getY() << "m ";
336 os << " thx = " << p.getTX() << "rad ";
337 os << " thy = " << p.getTY() << "rad ";
338 os << endl;
339 return os;
340}
341
342/// The phase space vector is (x,x',y,y',E)
343/// [x] = [y] = meters
344/// [x'] = [y'] = 1 with x' = dx/ds = tan (thetaX)
345/// [E] = GeV
346const TMatrixD * H_BeamParticle::getV() const {
347 double vec[MDIM] = {fx/URAD, tan(thx/URAD), fy/URAD, tan(thy/URAD),energy};
348 TMatrixD * mat = new TMatrixD(1,MDIM,vec);
349 return mat;
350}
351
352void H_BeamParticle::printV() const {
353 TMatrixD X(*getV());
354 cout << " x = " << (X.GetMatrixArray())[0] << "m ";
355 cout << " x' = " << (X.GetMatrixArray())[1] << " ";
356 cout << " y = " << (X.GetMatrixArray())[2] << "m ";
357 cout << " y' = " << (X.GetMatrixArray())[3] << " ";
358 cout << endl;
359 return;
360}
361
362void H_BeamParticle::propagate(const double position) {
363 /// @param position is the s coordinate in m to reach
364 /// Does not propagate if position is in the middle of an otics element of the beamline.
365 vector<TVectorD>::const_iterator position_i = positions.begin();
366 double l = 0.;
367 if(position != fs) { // avoid repeating the computation if already done at this position
368 if(position == (*position_i)[INDEX_S]) {
369 fs = position;
370 fx = (*position_i)[INDEX_X];
371 fy = (*position_i)[INDEX_Y];
372 thx= (*position_i)[INDEX_TX];
373 thy= (*position_i)[INDEX_TY];
374 return;
375 } else
376 for(position_i = positions.begin(); position_i < positions.end(); position_i++) {
377 if((*position_i)[INDEX_S]>=position) {
378 if(position_i==positions.begin()) {
379 if(VERBOSE) cout<<"<H_BeamParticle> ERROR : non reachable value"<<endl;
380 return;
381 }
382 l = (*position_i)[INDEX_S] - (*(position_i-1))[INDEX_S];
383 if(l==0) {
384 if(VERBOSE) cout<<"<H_BeamParticle> WARNING : no luck in choosing position, no propagation done"<<endl;
385 return;
386 }
387 fs = position;
388 fx = (*(position_i-1))[INDEX_X] + (position-(*(position_i-1))[INDEX_S])*((*position_i)[INDEX_X] - (*(position_i-1))[INDEX_X])/l;
389 fy = (*(position_i-1))[INDEX_Y] + (position-(*(position_i-1))[INDEX_S])*((*position_i)[INDEX_Y] - (*(position_i-1))[INDEX_Y])/l;
390 thx = (*(position_i-1))[INDEX_TX];
391 thy = (*(position_i-1))[INDEX_TY];
392 return;
393 }
394 }
395 position_i = positions.begin();
396 cout << "Desired position is : " << position << " & positions.begin() is " << (*position_i)[INDEX_S] << endl;
397 cout<<"<H_BeamParticle> ERROR : position not reachable"<<endl;
398 return;
399 }
400}
401
402/// Caution : do not use this method (obsolete) !!!
403void H_BeamParticle::propagate(const H_AbstractBeamLine * beam, const H_OpticalElement * element) {
404 TMatrixD X(*getV());
405 X *= beam->getPartialMatrix(element);
406 fx = URAD*(X.GetMatrixArray())[0];
407 thx = URAD*atan((X.GetMatrixArray())[1]);
408 fy = URAD*(X.GetMatrixArray())[2];
409 thy = URAD*atan((X.GetMatrixArray())[3]);
410 return;
411}
412
413void H_BeamParticle::propagate(const H_AbstractBeamLine * beam, const string& el_name) {
414 propagate(beam->getElement(el_name)->getS()+beam->getElement(el_name)->getLength());
415 return;
416}
417
418void H_BeamParticle::propagate(const H_AbstractBeamLine * beam) {
419 TMatrixD X(*getV());
420 X *= beam->getBeamMatrix();
421 fx = URAD*(X.GetMatrixArray())[0];
422 thx = URAD*atan((X.GetMatrixArray())[1]);
423 fy = URAD*(X.GetMatrixArray())[2];
424 thy = URAD*atan((X.GetMatrixArray())[3]);
425 return;
426}
427
428void H_BeamParticle::showPositions() const{
429 vector<TVectorD>::const_iterator position_i;
430 TVectorD temp_vec(LENGTH_VEC);
431
432 for(position_i = positions.begin(); position_i < positions.end(); position_i++) {
433 cout << "Vector (x,y,s) = (" << (*position_i)[INDEX_X] << ", " << (*position_i)[INDEX_Y] << ", " << (*position_i)[INDEX_S] << "). " << endl;
434 }
435 return ;
436}
437
438TGraph * H_BeamParticle::getPath(const int x_or_y, const int color) const{
439 /// @param x_or_y = 0(1) draws the x(y) component;
440
441 const int N = (int) positions.size();
442 int mycolor = color;
443 if(N<2) cout<<"<H_BeamParticle> WARNING : particle positions not calculated : please run computePath"<<endl;
444 double * s = new double[N], * graph = new double[N];
445
446 int index;
447 if(x_or_y==0) {index = INDEX_X;} else {index = INDEX_Y;}
448
449 vector<TVectorD>::const_iterator position_i;
450 for(position_i = positions.begin(); position_i < positions.end(); position_i++) {
451 graph[(int)(position_i-positions.begin())] = (*position_i)[index];
452 s[(int)(position_i-positions.begin())] = (*position_i)[INDEX_S];
453 }
454
455 TGraph * ppath = new TGraph(N,s,graph);
456 ppath->SetLineColor(mycolor);
457 delete [] s;
458 delete [] graph;
459 return ppath;
460}
461
462// should be removed later, to keep only computePath(const H_AbstractBeamLine & , const bool)
463void H_BeamParticle::computePath(const H_AbstractBeamLine * beam, const bool NonLinear) {
464 TMatrixD temp_mat(MDIM,MDIM);
465 double temp_x, temp_y, temp_s, temp_tx, temp_ty;
466
467 temp_x = (positions.front())[INDEX_X];
468 temp_tx = (positions.front())[INDEX_TX];
469 temp_y = (positions.front())[INDEX_Y];
470 temp_ty = (positions.front())[INDEX_TY];
471 temp_s = (positions.front())[INDEX_S];
472
473 double vec[MDIM] = {temp_x/URAD, tan(temp_tx/URAD), temp_y/URAD, tan(temp_ty/URAD),energy,1};
474
475 extern bool relative_energy;
476 if(relative_energy) {
477 vec[4] = energy-BE;
478 } else {
479 vec[4] = energy;
480 }
481
482 TMatrixD mat(1,MDIM,vec);
483
484 const int N =beam->getNumberOfElements();
485 double xys[LENGTH_VEC];
486
487 double energy_loss = NonLinear?BE-energy:0;
488
489 for (int i=0; i<N; i++) {
490 const unsigned pos = i;
491 if(fs < beam->getElement(pos)->getS() && fs > beam->getElement(pos-1)->getS()) {
492 if(beam->getElement(pos-1)->getType()!=DRIFT) {
493 cout<<"Path starts inside element "<<beam->getElement(pos-1)->getName()<<endl;
494 } else {
495 cout<<"Path starts inside unnamed drift "<<endl;
496 }
497 H_OpticalElement* temp_el = beam->getElement(pos-1)->clone();
498 temp_el->setS(fs);
499 temp_el->setLength(beam->getElement(pos)->getS() - fs);
500 mat[0][0] = mat[0][0] - temp_el->getX();
501 mat[0][1] = mat[0][1] - tan(temp_el->getTX());
502 mat[0][2] = mat[0][2] - temp_el->getY();
503 mat[0][3] = mat[0][3] - tan(temp_el->getTY());
504 mat *= temp_el->getMatrix(energy_loss,mp,qp);
505 mat[0][0] = mat[0][0] + temp_el->getX();
506 mat[0][1] = mat[0][1] + tan(temp_el->getTX());
507 mat[0][2] = mat[0][2] + temp_el->getY();
508 mat[0][3] = mat[0][3] + tan(temp_el->getTY());
509 xys[0] = mat.GetMatrixArray()[0]*URAD;
510 xys[1] = atan(mat.GetMatrixArray()[1])*URAD;
511 xys[2] = mat.GetMatrixArray()[2]*URAD;
512 xys[3] = atan(mat.GetMatrixArray()[3])*URAD;
513 xys[4] = temp_el->getS()+temp_el->getLength();
514 addPosition(xys[0],xys[1],xys[2],xys[3],xys[4]);
515 if (temp_el) delete temp_el;
516 }
517 if(fs <= beam->getElement(pos)->getS()) {
518 mat[0][0] = mat[0][0] - beam->getElement(pos)->getX();
519 mat[0][1] = mat[0][1] - tan(beam->getElement(pos)->getTX()/URAD)*URAD;
520 mat[0][2] = mat[0][2] - beam->getElement(pos)->getY();
521 mat[0][3] = mat[0][3] - tan(beam->getElement(pos)->getTY()/URAD)*URAD;
522 mat *= beam->getElement(pos)->getMatrix(energy_loss,mp,qp);
523 mat[0][0] = mat[0][0] + beam->getElement(pos)->getX();
524 mat[0][1] = mat[0][1] + tan(beam->getElement(pos)->getTX()/URAD)*URAD;
525 mat[0][2] = mat[0][2] + beam->getElement(pos)->getY();
526 mat[0][3] = mat[0][3] + tan(beam->getElement(pos)->getTY()/URAD)*URAD;
527 xys[0] = mat.GetMatrixArray()[0]*URAD;
528 xys[1] = atan(mat.GetMatrixArray()[1])*URAD;
529 xys[2] = mat.GetMatrixArray()[2]*URAD;
530 xys[3] = atan(mat.GetMatrixArray()[3])*URAD;
531 xys[4] = beam->getElement(pos)->getS()+beam->getElement(pos)->getLength();
532 addPosition(xys[0],xys[1],xys[2],xys[3],xys[4]);
533 }
534 }
535}
536
537// part about non-ip particle is not ready yet. use the above method in the meantime
538void H_BeamParticle::computePath(const H_AbstractBeamLine & beam, const bool NonLinear) {
539 TMatrixD temp_mat(MDIM,MDIM);
540 double temp_x, temp_y, temp_s, temp_tx, temp_ty;
541
542 temp_x = (positions.front())[INDEX_X];
543 temp_tx = (positions.front())[INDEX_TX];
544 temp_y = (positions.front())[INDEX_Y];
545 temp_ty = (positions.front())[INDEX_TY];
546 temp_s = (positions.front())[INDEX_S];
547
548 double vec[MDIM] = {temp_x/URAD, tan(temp_tx/URAD), temp_y/URAD, tan(temp_ty/URAD),energy,1};
549
550 extern bool relative_energy;
551 if(relative_energy) {
552 vec[4] = energy-BE;
553 } else {
554 vec[4] = energy;
555 }
556
557 TMatrixD mat(1,MDIM,vec);
558
559 const int N =beam.getNumberOfElements();
560 double xys[LENGTH_VEC];
561
562 double energy_loss = NonLinear?BE-energy:0;
563
564 // modify here to allow starting at non-IP positions
565 // s is distance to IP
566 // initial position is already in positions vector ?
567 for (int i=0; i<N; i++) {
568 const unsigned pos = i;
569 // if we are inside an element, we should start by adding the action
570 // of the rest of this element
571 if(pos > 0 && fs < beam.getElement(pos)->getS() && fs > beam.getElement(pos-1)->getS()) {
572 cout<<"Path starts inside element "<<beam.getElement(pos-1)->getName()<<endl;
573 H_OpticalElement* temp_el = new H_OpticalElement(*(beam.getElement(pos-1)));
574 temp_el->setS(fs);
575 temp_el->setLength(beam.getElement(pos)->getS() - fs);
576 mat[0][0] = mat[0][0] - temp_el->getX();
577 mat[0][1] = mat[0][1] - tan(temp_el->getTX());
578 mat[0][2] = mat[0][2] - temp_el->getY();
579 mat[0][3] = mat[0][3] - tan(temp_el->getTY());
580 mat *= temp_el->getMatrix(energy_loss,mp,qp);
581 mat[0][0] = mat[0][0] + temp_el->getX();
582 mat[0][1] = mat[0][1] + tan(temp_el->getTX());
583 mat[0][2] = mat[0][2] + temp_el->getY();
584 mat[0][3] = mat[0][3] + tan(temp_el->getTY());
585 } else if(fs >= beam.getElement(pos)->getS()) {
586 mat[0][0] = mat[0][0] - beam.getElement(pos)->getX();
587 mat[0][1] = mat[0][1] - tan(beam.getElement(pos)->getTX());
588 mat[0][2] = mat[0][2] - beam.getElement(pos)->getY();
589 mat[0][3] = mat[0][3] - tan(beam.getElement(pos)->getTY());
590 mat *= beam.getElement(pos)->getMatrix(energy_loss,mp,qp);
591 mat[0][0] = mat[0][0] + beam.getElement(pos)->getX();
592 mat[0][1] = mat[0][1] + tan(beam.getElement(pos)->getTX());
593 mat[0][2] = mat[0][2] + beam.getElement(pos)->getY();
594 mat[0][3] = mat[0][3] + tan(beam.getElement(pos)->getTY());
595 }
596 xys[0] = mat.GetMatrixArray()[0]*URAD;
597 xys[1] = atan(mat.GetMatrixArray()[1])*URAD;
598 xys[2] = mat.GetMatrixArray()[2]*URAD;
599 xys[3] = atan(mat.GetMatrixArray()[3])*URAD;
600 xys[4] = beam.getElement(pos)->getS()+beam.getElement(pos)->getLength();
601 addPosition(xys[0],xys[1],xys[2],xys[3],xys[4]);
602 fx = xys[0];
603 fy = xys[2];
604 thx = xys[1];
605 thy = xys[3];
606 }
607}
608
609void H_BeamParticle::resetPath() {
610 double temp_x, temp_y, temp_s, temp_tx, temp_ty;
611
612 temp_x = (positions.front())[INDEX_X];
613 temp_tx = (positions.front())[INDEX_TX];
614 temp_y = (positions.front())[INDEX_Y];
615 temp_ty = (positions.front())[INDEX_TY];
616 temp_s = (positions.front())[INDEX_S];
617 positions.clear();
618 addPosition(temp_x,temp_tx,temp_y,temp_ty,temp_s);
619}
620
621const TVectorD * H_BeamParticle::getPosition(const int element_position) const {
622 const int N = (element_position<0)?0:(( ((unsigned int) element_position)>positions.size()-1)?positions.size()-1:element_position);
623 return &(*(positions.begin()+N));// same as "return &positions[N];", but more efficient
624}
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