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source: git/external/TrackCovariance/TrkUtil.cc@ a47edcc

Last change on this file since a47edcc was a47edcc, checked in by Franco BEDESCHI <bed@…>, 3 years ago

Fixed issue with backward generated tracks

  • Property mode set to 100644
File size: 13.2 KB
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1#include "TrkUtil.h"
2#include <iostream>
3#include <algorithm>
4#include <TSpline.h>
5
6// Constructor
7TrkUtil::TrkUtil(Double_t Bz)
8{
9 fBz = Bz;
10 fGasSel = 0; // Default is He-Isobuthane (90-10)
11 fRmin = 0.0; // Lower DCH radius
12 fRmax = 0.0; // Higher DCH radius
13 fZmin = 0.0; // Lower DCH z
14 fZmax = 0.0; // Higher DCH z
15}
16TrkUtil::TrkUtil()
17{
18 fBz = 0.0;
19 fGasSel = 0; // Default is He-Isobuthane (90-10)
20 fRmin = 0.0; // Lower DCH radius
21 fRmax = 0.0; // Higher DCH radius
22 fZmin = 0.0; // Lower DCH z
23 fZmax = 0.0; // Higher DCH z
24}
25//
26// Destructor
27TrkUtil::~TrkUtil()
28{
29 fBz = 0.0;
30 fGasSel = 0; // Default is He-Isobuthane (90-10)
31 fRmin = 0.0; // Lower DCH radius
32 fRmax = 0.0; // Higher DCH radius
33 fZmin = 0.0; // Lower DCH z
34 fZmax = 0.0; // Higher DCH z
35}
36//
37// Helix parameters from position and momentum
38// static
39TVectorD TrkUtil::XPtoPar(TVector3 x, TVector3 p, Double_t Q, Double_t Bz)
40{
41 //
42 TVectorD Par(5);
43 // Transverse parameters
44 Double_t a = -Q * Bz * cSpeed(); // Units are Tesla, GeV and meters
45 Double_t pt = p.Pt();
46 Double_t C = a / (2 * pt); // Half curvature
47 //std::cout << "ObsTrk::XPtoPar: fB = " << fB << ", a = " << a << ", pt = " << pt << ", C = " << C << std::endl;
48 Double_t r2 = x(0) * x(0) + x(1) * x(1);
49 Double_t cross = x(0) * p(1) - x(1) * p(0);
50 Double_t T = sqrt(pt * pt - 2 * a * cross + a * a * r2);
51 Double_t phi0 = atan2((p(1) - a * x(0)) / T, (p(0) + a * x(1)) / T); // Phi0
52 Double_t D; // Impact parameter D
53 if (pt < 10.0) D = (T - pt) / a;
54 else D = (-2 * cross + a * r2) / (T + pt);
55 //
56 Par(0) = D; // Store D
57 Par(1) = phi0; // Store phi0
58 Par(2) = C; // Store C
59 //Longitudinal parameters
60 Double_t B = C * sqrt(TMath::Max(r2 - D * D, 0.0) / (1 + 2 * C * D));
61 Double_t st = asin(B) / C;
62 Double_t ct = p(2) / pt;
63 Double_t z0;
64 Double_t dot = x(0) * p(0) + x(1) * p(1);
65 if (dot > 0.0) z0 = x(2) - ct * st;
66 else z0 = x(2) + ct * st;
67 //
68 Par(3) = z0; // Store z0
69 Par(4) = ct; // Store cot(theta)
70 //
71 return Par;
72}
73// non-static
74TVectorD TrkUtil::XPtoPar(TVector3 x, TVector3 p, Double_t Q)
75{
76 //
77 TVectorD Par(5);
78 Double_t Bz = fBz;
79 Par = XPtoPar(x, p, Q, Bz);
80 //
81 return Par;
82}
83//
84TVector3 TrkUtil::ParToX(TVectorD Par)
85{
86 Double_t D = Par(0);
87 Double_t phi0 = Par(1);
88 Double_t z0 = Par(3);
89 //
90 TVector3 Xval;
91 Xval(0) = -D * sin(phi0);
92 Xval(1) = D * cos(phi0);
93 Xval(2) = z0;
94 //
95 return Xval;
96}
97//
98TVector3 TrkUtil::ParToP(TVectorD Par)
99{
100 if (fBz == 0.0)std::cout << "TrkUtil::ParToP: Warning Bz not set" << std::endl;
101 //
102 return ParToP(Par, fBz);
103}
104//
105TVector3 TrkUtil::ParToP(TVectorD Par, Double_t Bz)
106{
107 Double_t C = Par(2);
108 Double_t phi0 = Par(1);
109 Double_t ct = Par(4);
110 //
111 TVector3 Pval;
112 Double_t pt = Bz * cSpeed() / TMath::Abs(2 * C);
113 Pval(0) = pt * cos(phi0);
114 Pval(1) = pt * sin(phi0);
115 Pval(2) = pt * ct;
116 //
117 return Pval;
118}
119//
120Double_t TrkUtil::ParToQ(TVectorD Par)
121{
122 return TMath::Sign(1.0, -Par(2));
123}
124
125//
126// Parameter conversion to ACTS format
127TVectorD TrkUtil::ParToACTS(TVectorD Par)
128{
129 TVectorD pACTS(6); // Return vector
130 //
131 Double_t b = -cSpeed() * fBz / 2.;
132 pACTS(0) = 1000 * Par(0); // D from m to mm
133 pACTS(1) = 1000 * Par(3); // z0 from m to mm
134 pACTS(2) = Par(1); // Phi0 is unchanged
135 pACTS(3) = atan2(1.0, Par(4)); // Theta in [0, pi] range
136 pACTS(4) = Par(2) / (b * sqrt(1 + Par(4) * Par(4))); // q/p in GeV
137 pACTS(5) = 0.0; // Time: currently undefined
138 //
139 return pACTS;
140}
141// Covariance conversion to ACTS format
142TMatrixDSym TrkUtil::CovToACTS(TVectorD Par, TMatrixDSym Cov)
143{
144 TMatrixDSym cACTS(6); cACTS.Zero();
145 Double_t b = -cSpeed() * fBz / 2.;
146 //
147 // Fill derivative matrix
148 TMatrixD A(5, 5); A.Zero();
149 Double_t ct = Par(4); // cot(theta)
150 Double_t C = Par(2); // half curvature
151 A(0, 0) = 1000.; // D-D conversion to mm
152 A(1, 2) = 1.0; // phi0-phi0
153 A(2, 4) = 1.0 / (sqrt(1.0 + ct * ct) * b); // q/p-C
154 A(3, 1) = 1000.; // z0-z0 conversion to mm
155 A(4, 3) = -1.0 / (1.0 + ct * ct); // theta - cot(theta)
156 A(4, 4) = -C * ct / (b * pow(1.0 + ct * ct, 3.0 / 2.0)); // q/p-cot(theta)
157 //
158 TMatrixDSym Cv = Cov;
159 TMatrixD At(5, 5);
160 At.Transpose(A);
161 Cv.Similarity(At);
162 TMatrixDSub(cACTS, 0, 4, 0, 4) = Cv;
163 cACTS(5, 5) = 0.1; // Currently undefined: set to arbitrary value to avoid crashes
164 //
165 return cACTS;
166}
167//
168// Parameter conversion to ILC format
169TVectorD TrkUtil::ParToILC(TVectorD Par)
170{
171 TVectorD pILC(5); // Return vector
172 //
173 pILC(0) = Par(0) * 1.0e3; // d0 in mm
174 pILC(1) = Par(1); // phi0 is unchanged
175 pILC(2) = -2 * Par(2) * 1.0e-3; // w in mm^-1
176 pILC(3) = Par(3) * 1.0e3; // z0 in mm
177 pILC(4) = Par(4); // tan(lambda) = cot(theta)
178 //
179 return pILC;
180}
181// Covariance conversion to ILC format
182TMatrixDSym TrkUtil::CovToILC(TMatrixDSym Cov)
183{
184 TMatrixDSym cILC(5); cILC.Zero();
185 //
186 // Fill derivative matrix
187 TMatrixD A(5, 5); A.Zero();
188 //
189 A(0, 0) = 1.0e3; // D-d0 in mm
190 A(1, 1) = 1.0; // phi0-phi0
191 A(2, 2) = -2.0e-3; // w-C
192 A(3, 3) = 1.0e3; // z0-z0 conversion to mm
193 A(4, 4) = 1.0; // tan(lambda) - cot(theta)
194 //
195 TMatrixDSym Cv = Cov;
196 TMatrixD At(5, 5);
197 At.Transpose(A);
198 Cv.Similarity(At);
199 cILC = Cv;
200 //
201 return cILC;
202}
203//
204// Conversion from meters to mm
205TVectorD TrkUtil::ParToMm(TVectorD Par) // Parameter conversion
206{
207 TVectorD Pmm(5); // Return vector
208 //
209 Pmm(0) = Par(0) * 1.0e3; // d0 in mm
210 Pmm(1) = Par(1); // phi0 is unchanged
211 Pmm(2) = Par(2) * 1.0e-3; // C in mm^-1
212 Pmm(3) = Par(3) * 1.0e3; // z0 in mm
213 Pmm(4) = Par(4); // tan(lambda) = cot(theta) unchanged
214 //
215 return Pmm;
216}
217TMatrixDSym TrkUtil::CovToMm(TMatrixDSym Cov) // Covariance conversion
218{
219 TMatrixDSym Cmm(5); Cmm.Zero();
220 //
221 // Fill derivative matrix
222 TMatrixD A(5, 5); A.Zero();
223 //
224 A(0, 0) = 1.0e3; // D-d0 in mm
225 A(1, 1) = 1.0; // phi0-phi0
226 A(2, 2) = 1.0e-3; // C-C
227 A(3, 3) = 1.0e3; // z0-z0 conversion to mm
228 A(4, 4) = 1.0; // lambda - cot(theta)
229 //
230 TMatrixDSym Cv = Cov;
231 TMatrixD At(5, 5);
232 At.Transpose(A);
233 Cv.Similarity(At);
234 Cmm = Cv;
235 //
236 return Cmm;
237}
238//
239// Setup chamber volume
240void TrkUtil::SetDchBoundaries(Double_t Rmin, Double_t Rmax, Double_t Zmin, Double_t Zmax)
241{
242 fRmin = Rmin; // Lower DCH radius
243 fRmax = Rmax; // Higher DCH radius
244 fZmin = Zmin; // Lower DCH z
245 fZmax = Zmax; // Higher DCH z
246}
247//
248// Get Trakck length inside DCH volume
249Double_t TrkUtil::TrkLen(TVectorD Par)
250{
251 Double_t tLength = 0.0;
252 // Check if geometry is initialized
253 if (fZmin == 0.0 && fZmax == 0.0)
254 {
255 // No geometry set so send a warning and return 0
256 std::cout << "TrkUtil::TrkLen() called without a DCH volume defined" << std::endl;
257 }
258 else
259 {
260 //******************************************************************
261 // Determine the track length inside the chamber ****
262 //******************************************************************
263 //
264 // Track pararameters
265 Double_t D = Par(0); // Transverse impact parameter
266 Double_t phi0 = Par(1); // Transverse direction at minimum approach
267 Double_t C = Par(2); // Half curvature
268 Double_t z0 = Par(3); // Z at minimum approach
269 Double_t ct = Par(4); // cot(theta)
270 //std::cout << "TrkUtil:: parameters: D= " << D << ", phi0= " << phi0
271 // << ", C= " << C << ", z0= " << z0 << ", ct= " << ct << std::endl;
272 //
273 // Track length per unit phase change
274 Double_t Scale = sqrt(1.0 + ct * ct) / (2.0 * TMath::Abs(C));
275 //
276 // Find intersections with chamber boundaries
277 //
278 Double_t phRin = 0.0; // phase of inner cylinder
279 Double_t phRin2 = 0.0; // phase of inner cylinder intersection (2nd branch)
280 Double_t phRhi = 0.0; // phase of outer cylinder intersection
281 Double_t phZmn = 0.0; // phase of left wall intersection
282 Double_t phZmx = 0.0; // phase of right wall intersection
283 // ... with inner cylinder
284 Double_t Rtop = TMath::Abs((1.0 + C * D) / C);
285
286 if (Rtop > fRmin && TMath::Abs(D) < fRmin) // *** don't treat large D tracks for the moment ***
287 {
288 Double_t ph = 2 * asin(C * sqrt((fRmin * fRmin - D * D) / (1.0 + 2.0 * C * D)));
289 Double_t z = z0 + ct * ph / (2.0 * C);
290
291 //std::cout << "Rin intersection: ph = " << ph<<", z= "<<z << std::endl;
292
293 if (z < fZmax && z > fZmin) phRin = TMath::Abs(ph); // Intersection inside chamber volume
294 //
295 // Include second branch of loopers
296 Double_t Pi = 3.14159265358979323846;
297 Double_t ph2 = 2 * Pi - TMath::Abs(ph);
298 if (ph < 0)ph2 = -ph2;
299 z = z0 + ct * ph2 / (2.0 * C);
300 if (z < fZmax && z > fZmin) phRin2 = TMath::Abs(ph2); // Intersection inside chamber volume
301 }
302 // ... with outer cylinder
303 if (Rtop > fRmax && TMath::Abs(D) < fRmax) // *** don't treat large D tracks for the moment ***
304 {
305 Double_t ph = 2 * asin(C * sqrt((fRmax * fRmax - D * D) / (1.0 + 2.0 * C * D)));
306 Double_t z = z0 + ct * ph / (2.0 * C);
307 if (z < fZmax && z > fZmin) phRhi = TMath::Abs(ph); // Intersection inside chamber volume
308 }
309 // ... with left wall
310 Double_t Zdir = (fZmin - z0) / ct;
311 if (Zdir > 0.0)
312 {
313 Double_t ph = 2.0 * C * Zdir;
314 Double_t Rint = sqrt(D * D + (1.0 + 2.0 * C * D) * pow(sin(ph / 2), 2) / (C * C));
315 if (Rint < fRmax && Rint > fRmin) phZmn = TMath::Abs(ph); // Intersection inside chamber volume
316 }
317 // ... with right wall
318 Zdir = (fZmax - z0) / ct;
319 if (Zdir > 0.0)
320 {
321 Double_t ph = 2.0 * C * Zdir;
322 Double_t Rint = sqrt(D * D + (1.0 + 2.0 * C * D) * pow(sin(ph / 2), 2) / (C * C));
323 if (Rint < fRmax && Rint > fRmin) phZmx = TMath::Abs(ph); // Intersection inside chamber volume
324 }
325 //
326 // Order phases and keep the lowest two non-zero ones
327 //
328 const Int_t Nint = 5;
329 Double_t dPhase = 0.0; // Phase difference between two close intersections
330 Double_t ph_arr[Nint] = { phRin, phRin2, phRhi, phZmn, phZmx };
331 std::sort(ph_arr, ph_arr + Nint);
332 Int_t iPos = -1; // First element > 0
333 for (Int_t i = 0; i < Nint; i++)
334 {
335 if (ph_arr[i] <= 0.0) iPos = i;
336 }
337
338 if (iPos < Nint - 2)
339 {
340 dPhase = ph_arr[iPos + 2] - ph_arr[iPos + 1];
341 tLength = dPhase * Scale;
342 }
343 }
344 return tLength;
345}
346//
347// Return number of ionization clusters
348Bool_t TrkUtil::IonClusters(Double_t& Ncl, Double_t mass, TVectorD Par)
349{
350 //
351 // Units are meters/Tesla/GeV
352 //
353 Ncl = 0.0;
354 Bool_t Signal = kFALSE;
355 Double_t tLen = 0;
356 // Check if geometry is initialized
357 if (fZmin == 0.0 && fZmax == 0.0)
358 {
359 // No geometry set so send a warning and return 0
360 std::cout << "TrkUtil::IonClusters() called without a volume defined" << std::endl;
361 }
362 else tLen = TrkLen(Par);
363
364 //******************************************************************
365 // Now get the number of clusters ****
366 //******************************************************************
367 //
368 Double_t muClu = 0.0; // mean number of clusters
369 Double_t bg = 0.0; // beta*gamma
370 Ncl = 0.0;
371 if (tLen > 0.0)
372 {
373 Signal = kTRUE;
374 //
375 // Find beta*gamma
376 if (fBz == 0.0)
377 {
378 Signal = kFALSE;
379 std::cout << "TrkUtil::IonClusters: Please set Bz!!!" << std::endl;
380 }
381 else
382 {
383 TVector3 p = ParToP(Par);
384 bg = p.Mag() / mass;
385 muClu = Nclusters(bg) * tLen; // Avg. number of clusters
386
387 Ncl = gRandom->PoissonD(muClu); // Actual number of clusters
388 }
389
390 }
391 //
392 return Signal;
393}
394//
395//
396Double_t TrkUtil::Nclusters(Double_t begam)
397{
398 Int_t Opt = fGasSel;
399 Double_t Nclu = Nclusters(begam, Opt);
400 //
401 return Nclu;
402}
403//
404Double_t TrkUtil::Nclusters(Double_t begam, Int_t Opt) {
405 //
406 // Opt = 0: He 90 - Isobutane 10
407 // = 1: pure He
408 // = 2: Argon 50 - Ethane 50
409 // = 3: pure Argon
410 //
411 //
412 const Int_t Npt = 18;
413 Double_t bg[Npt] = { 0.5, 0.8, 1., 2., 3., 4., 5., 8., 10.,
414 12., 15., 20., 50., 100., 200., 500., 1000., 10000. };
415 //
416 // He 90 - Isobutane 10
417 Double_t ncl_He_Iso[Npt] = { 42.94, 23.6,18.97,12.98,12.2,12.13,
418 12.24,12.73,13.03,13.29,13.63,14.08,15.56,16.43,16.8,16.95,16.98, 16.98 };
419 //
420 // pure He
421 Double_t ncl_He[Npt] = { 11.79,6.5,5.23,3.59,3.38,3.37,3.4,3.54,3.63,
422 3.7,3.8,3.92,4.33,4.61,4.78,4.87,4.89, 4.89 };
423 //
424 // Argon 50 - Ethane 50
425 Double_t ncl_Ar_Eth[Npt] = { 130.04,71.55,57.56,39.44,37.08,36.9,
426 37.25,38.76,39.68,40.49,41.53,42.91,46.8,48.09,48.59,48.85,48.93,48.93 };
427 //
428 // pure Argon
429 Double_t ncl_Ar[Npt] = { 88.69,48.93,39.41,27.09,25.51,25.43,25.69,
430 26.78,27.44,28.02,28.77,29.78,32.67,33.75,34.24,34.57,34.68, 34.68 };
431 //
432 Double_t ncl[Npt];
433 switch (Opt)
434 {
435 case 0: std::copy(ncl_He_Iso, ncl_He_Iso + Npt, ncl); // He-Isobutane
436 break;
437 case 1: std::copy(ncl_He, ncl_He + Npt, ncl); // pure He
438 break;
439 case 2: std::copy(ncl_Ar_Eth, ncl_Ar_Eth + Npt, ncl); // Argon - Ethane
440 break;
441 case 3: std::copy(ncl_Ar, ncl_Ar + Npt, ncl); // pure Argon
442 break;
443 }
444 //
445 Double_t interp = 0.0;
446 TSpline3* sp3 = new TSpline3("sp3", bg, ncl, Npt);
447 if (begam > bg[0] && begam < bg[Npt - 1]) interp = sp3->Eval(begam);
448 return 100 * interp;
449}
450//
451Double_t TrkUtil::funcNcl(Double_t* xp, Double_t* par) {
452 Double_t bg = xp[0];
453 return Nclusters(bg);
454}
455//
456void TrkUtil::SetGasMix(Int_t Opt)
457{
458 if (Opt < 0 || Opt > 3)
459 {
460 std::cout << "TrkUtil::SetGasMix Gas option not allowed. No action."
461 << std::endl;
462 }
463 else fGasSel = Opt;
464}
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