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source: git/external/TrackCovariance/TrkUtil.cc@ 53f4746

Last change on this file since 53f4746 was 53f4746, checked in by Franco BEDESCHI <bed@…>, 4 years ago

Cluster counting example and VertexFit update

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[82db145]1#include "TrkUtil.h"
2#include <iostream>
[c5696dd]3#include <algorithm>
[53f4746]4#include <TSpline.h>
[82db145]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.Perp2();
49 Double_t cross = x(0) * p(1) - x(1) * p(0);
[c5696dd]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
[82db145]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
[c5696dd]60 Double_t B = C * sqrt(TMath::Max(r2 - D * D, 0.0) / (1 + 2 * C * D));
61 Double_t st = asin(B) / C;
[82db145]62 Double_t ct = p(2) / pt;
63 Double_t z0 = x(2) - ct * st;
64 //
65 Par(3) = z0; // Store z0
66 Par(4) = ct; // Store cot(theta)
67 //
68 return Par;
69}
70// non-static
71TVectorD TrkUtil::XPtoPar(TVector3 x, TVector3 p, Double_t Q)
72{
73 //
74 TVectorD Par(5);
75 Double_t Bz = fBz;
76 Par = XPtoPar(x, p, Q, Bz);
77 //
78 return Par;
79}
80//
81TVector3 TrkUtil::ParToX(TVectorD Par)
82{
83 Double_t D = Par(0);
84 Double_t phi0 = Par(1);
85 Double_t z0 = Par(3);
86 //
87 TVector3 Xval;
[c5696dd]88 Xval(0) = -D * sin(phi0);
89 Xval(1) = D * cos(phi0);
[82db145]90 Xval(2) = z0;
91 //
92 return Xval;
93}
94//
95TVector3 TrkUtil::ParToP(TVectorD Par)
96{
97 if (fBz == 0.0)std::cout << "TrkUtil::ParToP: Warning Bz not set" << std::endl;
98 //
[53f4746]99 return ParToP(Par, fBz);
[82db145]100}
101//
102TVector3 TrkUtil::ParToP(TVectorD Par, Double_t Bz)
103{
104 Double_t C = Par(2);
105 Double_t phi0 = Par(1);
106 Double_t ct = Par(4);
107 //
108 TVector3 Pval;
109 Double_t pt = Bz * cSpeed() / TMath::Abs(2 * C);
[c5696dd]110 Pval(0) = pt * cos(phi0);
111 Pval(1) = pt * sin(phi0);
[82db145]112 Pval(2) = pt * ct;
113 //
114 return Pval;
115}
116//
117Double_t TrkUtil::ParToQ(TVectorD Par)
118{
119 return TMath::Sign(1.0, -Par(2));
120}
121
122//
123// Parameter conversion to ACTS format
124TVectorD TrkUtil::ParToACTS(TVectorD Par)
125{
126 TVectorD pACTS(6); // Return vector
127 //
128 Double_t b = -cSpeed() * fBz / 2.;
129 pACTS(0) = 1000 * Par(0); // D from m to mm
130 pACTS(1) = 1000 * Par(3); // z0 from m to mm
131 pACTS(2) = Par(1); // Phi0 is unchanged
[c5696dd]132 pACTS(3) = atan2(1.0, Par(4)); // Theta in [0, pi] range
133 pACTS(4) = Par(2) / (b * sqrt(1 + Par(4) * Par(4))); // q/p in GeV
[82db145]134 pACTS(5) = 0.0; // Time: currently undefined
135 //
136 return pACTS;
137}
138// Covariance conversion to ACTS format
139TMatrixDSym TrkUtil::CovToACTS(TVectorD Par, TMatrixDSym Cov)
140{
141 TMatrixDSym cACTS(6); cACTS.Zero();
142 Double_t b = -cSpeed() * fBz / 2.;
143 //
144 // Fill derivative matrix
145 TMatrixD A(5, 5); A.Zero();
146 Double_t ct = Par(4); // cot(theta)
147 Double_t C = Par(2); // half curvature
148 A(0, 0) = 1000.; // D-D conversion to mm
149 A(1, 2) = 1.0; // phi0-phi0
[c5696dd]150 A(2, 4) = 1.0 / (sqrt(1.0 + ct * ct) * b); // q/p-C
[82db145]151 A(3, 1) = 1000.; // z0-z0 conversion to mm
152 A(4, 3) = -1.0 / (1.0 + ct * ct); // theta - cot(theta)
153 A(4, 4) = -C * ct / (b * pow(1.0 + ct * ct, 3.0 / 2.0)); // q/p-cot(theta)
154 //
155 TMatrixDSym Cv = Cov;
156 TMatrixD At(5, 5);
157 At.Transpose(A);
158 Cv.Similarity(At);
159 TMatrixDSub(cACTS, 0, 4, 0, 4) = Cv;
160 cACTS(5, 5) = 0.1; // Currently undefined: set to arbitrary value to avoid crashes
161 //
162 return cACTS;
163}
164//
165// Parameter conversion to ILC format
166TVectorD TrkUtil::ParToILC(TVectorD Par)
167{
168 TVectorD pILC(5); // Return vector
169 //
170 pILC(0) = Par(0) * 1.0e3; // d0 in mm
171 pILC(1) = Par(1); // phi0 is unchanged
172 pILC(2) = -2 * Par(2) * 1.0e-3; // w in mm^-1
173 pILC(3) = Par(3) * 1.0e3; // z0 in mm
174 pILC(4) = Par(4); // tan(lambda) = cot(theta)
175 //
176 return pILC;
177}
178// Covariance conversion to ILC format
179TMatrixDSym TrkUtil::CovToILC(TMatrixDSym Cov)
180{
181 TMatrixDSym cILC(5); cILC.Zero();
182 //
183 // Fill derivative matrix
184 TMatrixD A(5, 5); A.Zero();
185 //
186 A(0, 0) = 1.0e3; // D-d0 in mm
187 A(1, 1) = 1.0; // phi0-phi0
188 A(2, 2) = -2.0e-3; // w-C
189 A(3, 3) = 1.0e3; // z0-z0 conversion to mm
190 A(4, 4) = 1.0; // tan(lambda) - cot(theta)
191 //
192 TMatrixDSym Cv = Cov;
193 TMatrixD At(5, 5);
194 At.Transpose(A);
195 Cv.Similarity(At);
196 cILC = Cv;
197 //
198 return cILC;
199}
200//
201// Conversion from meters to mm
202TVectorD TrkUtil::ParToMm(TVectorD Par) // Parameter conversion
203{
204 TVectorD Pmm(5); // Return vector
205 //
206 Pmm(0) = Par(0) * 1.0e3; // d0 in mm
207 Pmm(1) = Par(1); // phi0 is unchanged
208 Pmm(2) = Par(2) * 1.0e-3; // C in mm^-1
209 Pmm(3) = Par(3) * 1.0e3; // z0 in mm
210 Pmm(4) = Par(4); // tan(lambda) = cot(theta) unchanged
211 //
212 return Pmm;
213}
214TMatrixDSym TrkUtil::CovToMm(TMatrixDSym Cov) // Covariance conversion
215{
216 TMatrixDSym Cmm(5); Cmm.Zero();
217 //
218 // Fill derivative matrix
219 TMatrixD A(5, 5); A.Zero();
220 //
221 A(0, 0) = 1.0e3; // D-d0 in mm
222 A(1, 1) = 1.0; // phi0-phi0
223 A(2, 2) = 1.0e-3; // C-C
224 A(3, 3) = 1.0e3; // z0-z0 conversion to mm
225 A(4, 4) = 1.0; // lambda - cot(theta)
226 //
227 TMatrixDSym Cv = Cov;
228 TMatrixD At(5, 5);
229 At.Transpose(A);
230 Cv.Similarity(At);
231 Cmm = Cv;
232 //
233 return Cmm;
234}
235//
236// Setup chamber volume
237void TrkUtil::SetDchBoundaries(Double_t Rmin, Double_t Rmax, Double_t Zmin, Double_t Zmax)
238{
239 fRmin = Rmin; // Lower DCH radius
240 fRmax = Rmax; // Higher DCH radius
241 fZmin = Zmin; // Lower DCH z
242 fZmax = Zmax; // Higher DCH z
243}
244//
245// Get Trakck length inside DCH volume
246Double_t TrkUtil::TrkLen(TVectorD Par)
247{
248 Double_t tLength = 0.0;
249 // Check if geometry is initialized
250 if (fZmin == 0.0 && fZmax == 0.0)
251 {
252 // No geometry set so send a warning and return 0
253 std::cout << "TrkUtil::TrkLen() called without a DCH volume defined" << std::endl;
254 }
255 else
256 {
257 //******************************************************************
258 // Determine the track length inside the chamber ****
259 //******************************************************************
260 //
261 // Track pararameters
262 Double_t D = Par(0); // Transverse impact parameter
263 Double_t phi0 = Par(1); // Transverse direction at minimum approach
264 Double_t C = Par(2); // Half curvature
265 Double_t z0 = Par(3); // Z at minimum approach
266 Double_t ct = Par(4); // cot(theta)
267 //std::cout << "TrkUtil:: parameters: D= " << D << ", phi0= " << phi0
268 // << ", C= " << C << ", z0= " << z0 << ", ct= " << ct << std::endl;
269 //
[53f4746]270 // Track length per unit phase change
271 Double_t Scale = sqrt(1.0 + ct * ct) / (2.0 * TMath::Abs(C));
[82db145]272 //
273 // Find intersections with chamber boundaries
274 //
[53f4746]275 Double_t phRin = 0.0; // phase of inner cylinder
276 Double_t phRin2 = 0.0; // phase of inner cylinder intersection (2nd branch)
[82db145]277 Double_t phRhi = 0.0; // phase of outer cylinder intersection
278 Double_t phZmn = 0.0; // phase of left wall intersection
279 Double_t phZmx = 0.0; // phase of right wall intersection
280 // ... with inner cylinder
[53f4746]281 Double_t Rtop = TMath::Abs((1.0 + C * D) / C);
[82db145]282
283 if (Rtop > fRmin && TMath::Abs(D) < fRmin) // *** don't treat large D tracks for the moment ***
284 {
[53f4746]285 Double_t ph = 2 * asin(C * sqrt((fRmin * fRmin - D * D) / (1.0 + 2.0 * C * D)));
286 Double_t z = z0 + ct * ph / (2.0 * C);
[82db145]287
288 //std::cout << "Rin intersection: ph = " << ph<<", z= "<<z << std::endl;
289
[53f4746]290 if (z < fZmax && z > fZmin) phRin = TMath::Abs(ph); // Intersection inside chamber volume
[82db145]291 //
292 // Include second branch of loopers
[59ba063]293 Double_t Pi = 3.14159265358979323846;
[53f4746]294 Double_t ph2 = 2 * Pi - TMath::Abs(ph);
[82db145]295 if (ph < 0)ph2 = -ph2;
296 z = z0 + ct * ph2 / (2.0 * C);
297 if (z < fZmax && z > fZmin) phRin2 = TMath::Abs(ph2); // Intersection inside chamber volume
298 }
299 // ... with outer cylinder
300 if (Rtop > fRmax && TMath::Abs(D) < fRmax) // *** don't treat large D tracks for the moment ***
301 {
[53f4746]302 Double_t ph = 2 * asin(C * sqrt((fRmax * fRmax - D * D) / (1.0 + 2.0 * C * D)));
303 Double_t z = z0 + ct * ph / (2.0 * C);
304 if (z < fZmax && z > fZmin) phRhi = TMath::Abs(ph); // Intersection inside chamber volume
[82db145]305 }
306 // ... with left wall
307 Double_t Zdir = (fZmin - z0) / ct;
308 if (Zdir > 0.0)
309 {
[53f4746]310 Double_t ph = 2.0 * C * Zdir;
311 Double_t Rint = sqrt(D * D + (1.0 + 2.0 * C * D) * pow(sin(ph / 2), 2) / (C * C));
312 if (Rint < fRmax && Rint > fRmin) phZmn = TMath::Abs(ph); // Intersection inside chamber volume
[82db145]313 }
314 // ... with right wall
315 Zdir = (fZmax - z0) / ct;
316 if (Zdir > 0.0)
317 {
[53f4746]318 Double_t ph = 2.0 * C * Zdir;
319 Double_t Rint = sqrt(D * D + (1.0 + 2.0 * C * D) * pow(sin(ph / 2), 2) / (C * C));
320 if (Rint < fRmax && Rint > fRmin) phZmx = TMath::Abs(ph); // Intersection inside chamber volume
[82db145]321 }
322 //
323 // Order phases and keep the lowest two non-zero ones
324 //
325 const Int_t Nint = 5;
326 Double_t dPhase = 0.0; // Phase difference between two close intersections
327 Double_t ph_arr[Nint] = { phRin, phRin2, phRhi, phZmn, phZmx };
[59ba063]328 std::sort(ph_arr, ph_arr + Nint);
[82db145]329 Int_t iPos = -1; // First element > 0
330 for (Int_t i = 0; i < Nint; i++)
331 {
[59ba063]332 if (ph_arr[i] <= 0.0) iPos = i;
[82db145]333 }
334
335 if (iPos < Nint - 2)
336 {
[59ba063]337 dPhase = ph_arr[iPos + 2] - ph_arr[iPos + 1];
[53f4746]338 tLength = dPhase * Scale;
[82db145]339 }
340 }
341 return tLength;
342}
343//
344// Return number of ionization clusters
[53f4746]345Bool_t TrkUtil::IonClusters(Double_t& Ncl, Double_t mass, TVectorD Par)
[82db145]346{
347 //
348 // Units are meters/Tesla/GeV
349 //
350 Ncl = 0.0;
351 Bool_t Signal = kFALSE;
352 Double_t tLen = 0;
353 // Check if geometry is initialized
354 if (fZmin == 0.0 && fZmax == 0.0)
355 {
356 // No geometry set so send a warning and return 0
357 std::cout << "TrkUtil::IonClusters() called without a volume defined" << std::endl;
358 }
359 else tLen = TrkLen(Par);
360
361 //******************************************************************
362 // Now get the number of clusters ****
363 //******************************************************************
364 //
365 Double_t muClu = 0.0; // mean number of clusters
366 Double_t bg = 0.0; // beta*gamma
367 Ncl = 0.0;
368 if (tLen > 0.0)
369 {
370 Signal = kTRUE;
371 //
372 // Find beta*gamma
373 if (fBz == 0.0)
374 {
375 Signal = kFALSE;
376 std::cout << "TrkUtil::IonClusters: Please set Bz!!!" << std::endl;
377 }
378 else
379 {
380 TVector3 p = ParToP(Par);
381 bg = p.Mag() / mass;
[53f4746]382 muClu = Nclusters(bg) * tLen; // Avg. number of clusters
[82db145]383
384 Ncl = gRandom->PoissonD(muClu); // Actual number of clusters
385 }
386
387 }
[53f4746]388 //
[82db145]389 return Signal;
390}
391//
392//
[a95da74]393Double_t TrkUtil::Nclusters(Double_t begam)
[82db145]394{
395 Int_t Opt = fGasSel;
396 Double_t Nclu = Nclusters(begam, Opt);
397 //
398 return Nclu;
399}
400//
401Double_t TrkUtil::Nclusters(Double_t begam, Int_t Opt) {
402 //
403 // Opt = 0: He 90 - Isobutane 10
404 // = 1: pure He
405 // = 2: Argon 50 - Ethane 50
406 // = 3: pure Argon
407 //
408 //
[4df491e]409 const Int_t Npt = 18;
410 Double_t bg[Npt] = { 0.5, 0.8, 1., 2., 3., 4., 5., 8., 10.,
411 12., 15., 20., 50., 100., 200., 500., 1000., 10000. };
412 //
413 // He 90 - Isobutane 10
414 Double_t ncl_He_Iso[Npt] = { 42.94, 23.6,18.97,12.98,12.2,12.13,
415 12.24,12.73,13.03,13.29,13.63,14.08,15.56,16.43,16.8,16.95,16.98, 16.98 };
416 //
417 // pure He
418 Double_t ncl_He[Npt] = { 11.79,6.5,5.23,3.59,3.38,3.37,3.4,3.54,3.63,
419 3.7,3.8,3.92,4.33,4.61,4.78,4.87,4.89, 4.89 };
420 //
421 // Argon 50 - Ethane 50
422 Double_t ncl_Ar_Eth[Npt] = { 130.04,71.55,57.56,39.44,37.08,36.9,
423 37.25,38.76,39.68,40.49,41.53,42.91,46.8,48.09,48.59,48.85,48.93,48.93 };
424 //
425 // pure Argon
426 Double_t ncl_Ar[Npt] = { 88.69,48.93,39.41,27.09,25.51,25.43,25.69,
427 26.78,27.44,28.02,28.77,29.78,32.67,33.75,34.24,34.57,34.68, 34.68 };
428 //
429 Double_t ncl[Npt];
[53f4746]430 switch (Opt)
431 {
432 case 0: std::copy(ncl_He_Iso, ncl_He_Iso + Npt, ncl); // He-Isobutane
[a95da74]433 break;
[53f4746]434 case 1: std::copy(ncl_He, ncl_He + Npt, ncl); // pure He
[4df491e]435 break;
[53f4746]436 case 2: std::copy(ncl_Ar_Eth, ncl_Ar_Eth + Npt, ncl); // Argon - Ethane
[4df491e]437 break;
[53f4746]438 case 3: std::copy(ncl_Ar, ncl_Ar + Npt, ncl); // pure Argon
[4df491e]439 break;
[53f4746]440 }
441 //
442 Double_t interp = 0.0;
443 TSpline3* sp3 = new TSpline3("sp3", bg, ncl, Npt);
444 if (begam > bg[0] && begam < bg[Npt - 1]) interp = sp3->Eval(begam);
445 if(begam < bg[0]) interp = bg[0];
446 if(begam > bg[Npt-1]) interp = bg[Npt-1];
447 return 100 * interp;
[82db145]448}
449//
[53f4746]450Double_t TrkUtil::funcNcl(Double_t* xp, Double_t* par) {
[82db145]451 Double_t bg = xp[0];
452 return Nclusters(bg);
453}
454//
455void TrkUtil::SetGasMix(Int_t Opt)
456{
457 if (Opt < 0 || Opt > 3)
458 {
459 std::cout << "TrkUtil::SetGasMix Gas option not allowed. No action."
460 << std::endl;
461 }
462 else fGasSel = Opt;
[c5696dd]463}
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