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Analysis/VertexFit/VertexFit-00-02-88/src/Helix.cxx
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1//
2// $Id: Helix.cxx,v 1.5 2011/04/11 13:31:08 azhemchugov Exp $
3//
4// Class VFHelix
5//
6// Author Date comments
7// Y.Ohnishi 03/01/1997 original version
8// Y.Ohnishi 06/03/1997 updated
9// Y.Iwasaki 17/02/1998 BFILED removed, func. name changed, func. added
10// J.Tanaka 06/12/1998 add some utilities.
11// Y.Iwasaki 07/07/1998 cache added to speed up
12//
13
14#include <cmath>
15#include <cfloat>
16#include "VertexFit/Helix.h"
17#include "VertexFit/BField.h"
18
19// const double
20// VFHelix::m_BFIELD = 10.0; // KG
21// const double
22// VFHelix::m_ALPHA = 222.376063; // = 10000. / 2.99792458 / BFIELD
23// now VFHelix::m_ALPHA = 333.564095;
24
25const double
26M_PI2 = 2. * M_PI;
27
28const double
29M_PI4 = 4. * M_PI;
30
31const double
32M_PI8 = 8. * M_PI;
33
34const double
35VFHelix::ConstantAlpha = 333.564095;
36
38 const HepVector & a,
39 const HepSymMatrix & Ea)
40: m_bField(10.0),
41 m_alpha(333.564095),
42 m_pivot(pivot),
43 m_a(a),
44 m_Ea(Ea),
45 m_matrixValid(true)
46{
47 // m_alpha = 10000. / 2.99792458 / m_bField;
48 // m_alpha = 333.564095;
49 m_bField = 10 * VertexFitBField::instance()->getBFieldZRef();
50 m_alpha = 10000. / 2.99792458 / m_bField;
51 //std::cout << "m_bField = " << m_bField << " m_alpha = " << m_alpha << std::endl;
52 updateCache();
53}
54
56 const HepVector & a)
57: m_bField(10.0),
58 m_alpha(333.564095),
59 m_pivot(pivot),
60 m_a(a),
61 m_Ea(HepSymMatrix(5,0)),
62 m_matrixValid(false)
63{
64 // m_alpha = 333.564095;
65 m_bField = 10 * VertexFitBField::instance()->getBFieldZRef();
66 m_alpha = 10000. / 2.99792458 / m_bField;
67
68 updateCache();
69}
70
72 const Hep3Vector & momentum,
73 double charge)
74: m_bField(10.0),
75 m_alpha(333.564095),
76 m_pivot(position),
77 m_a(HepVector(5,0)),
78 m_Ea(HepSymMatrix(5,0)),
79 m_matrixValid(false)
80{
81
82 m_bField = 10 * VertexFitBField::instance()->getBFieldZRef();
83 m_alpha = 10000. / 2.99792458 / m_bField;
84
85 m_a[0] = 0.;
86 m_a[1] = fmod(atan2(- momentum.x(), momentum.y())
87 + M_PI4, M_PI2);
88 m_a[3] = 0.;
89 double perp(momentum.perp());
90 if (perp != 0.0) {
91 m_a[2] = charge / perp;
92 m_a[4] = momentum.z() / perp;
93 }
94 else {
95 m_a[2] = charge * (DBL_MAX);
96 if (momentum.z() >= 0) {
97 m_a[4] = (DBL_MAX);
98 } else {
99 m_a[4] = -(DBL_MAX);
100 }
101 }
102 // m_alpha = 333.564095;
103 updateCache();
104}
105
107}
108
110VFHelix::x(double phi) const {
111 //
112 // Calculate position (x,y,z) along helix.
113 //
114 // x = x0 + dr * cos(phi0) + (alpha / kappa) * (cos(phi0) - cos(phi0+phi))
115 // y = y0 + dr * sin(phi0) + (alpha / kappa) * (sin(phi0) - sin(phi0+phi))
116 // z = z0 + dz - (alpha / kappa) * tan(lambda) * phi
117 //
118
119 double x = m_pivot.x() + m_ac[0] * m_cp + m_r * (m_cp - cos(m_ac[1] +phi));
120 double y = m_pivot.y() + m_ac[0] * m_sp + m_r * (m_sp - sin(m_ac[1] +phi));
121 double z = m_pivot.z() + m_ac[3] - m_r * m_ac[4] * phi;
122
123 return HepPoint3D(x, y, z);
124}
125
126double *
127VFHelix::x(double phi, double p[3]) const {
128 //
129 // Calculate position (x,y,z) along helix.
130 //
131 // x = x0 + dr * cos(phi0) + (alpha / kappa) * (cos(phi0) - cos(phi0+phi))
132 // y = y0 + dr * sin(phi0) + (alpha / kappa) * (sin(phi0) - sin(phi0+phi))
133 // z = z0 + dz - (alpha / kappa) * tan(lambda) * phi
134 //
135
136 p[0] = m_pivot.x() + m_ac[0] * m_cp + m_r * (m_cp - cos(m_ac[1] + phi));
137 p[1] = m_pivot.y() + m_ac[0] * m_sp + m_r * (m_sp - sin(m_ac[1] + phi));
138 p[2] = m_pivot.z() + m_ac[3] - m_r * m_ac[4] * phi;
139
140 return p;
141}
142
144VFHelix::x(double phi, HepSymMatrix & Ex) const {
145 double x = m_pivot.x() + m_ac[0] * m_cp + m_r * (m_cp - cos(m_ac[1] +phi));
146 double y = m_pivot.y() + m_ac[0] * m_sp + m_r * (m_sp - sin(m_ac[1] +phi));
147 double z = m_pivot.z() + m_ac[3] - m_r * m_ac[4] * phi;
148
149 //
150 // Calculate position error matrix.
151 // Ex(phi) = (@x/@a)(Ea)(@x/@a)^T, phi is deflection angle to specify the
152 // point to be calcualted.
153 //
154 // HepMatrix dXDA(3, 5, 0);
155 // dXDA = delXDelA(phi);
156 // Ex.assign(dXDA * m_Ea * dXDA.T());
157
158 if (m_matrixValid) Ex = m_Ea.similarity(delXDelA(phi));
159 else Ex = m_Ea;
160
161 return HepPoint3D(x, y, z);
162}
163
164Hep3Vector
165VFHelix::momentum(double phi) const {
166 //
167 // Calculate momentum.
168 //
169 // Pt = | 1/kappa | (GeV/c)
170 //
171 // Px = -Pt * sin(phi0 + phi)
172 // Py = Pt * cos(phi0 + phi)
173 // Pz = Pt * tan(lambda)
174 //
175
176 double pt = fabs(m_pt);
177 double px = - pt * sin(m_ac[1] + phi);
178 double py = pt * cos(m_ac[1] + phi);
179 double pz = pt * m_ac[4];
180
181 return Hep3Vector(px, py, pz);
182}
183
184Hep3Vector
185VFHelix::momentum(double phi, HepSymMatrix & Em) const {
186 //
187 // Calculate momentum.
188 //
189 // Pt = | 1/kappa | (GeV/c)
190 //
191 // Px = -Pt * sin(phi0 + phi)
192 // Py = Pt * cos(phi0 + phi)
193 // Pz = Pt * tan(lambda)
194 //
195
196 double pt = fabs(m_pt);
197 double px = - pt * sin(m_ac[1] + phi);
198 double py = pt * cos(m_ac[1] + phi);
199 double pz = pt * m_ac[4];
200
201 if (m_matrixValid) Em = m_Ea.similarity(delMDelA(phi));
202 else Em = m_Ea;
203
204 return Hep3Vector(px, py, pz);
205}
206
207HepLorentzVector
208VFHelix::momentum(double phi, double mass) const {
209 //
210 // Calculate momentum.
211 //
212 // Pt = | 1/kappa | (GeV/c)
213 //
214 // Px = -Pt * sin(phi0 + phi)
215 // Py = Pt * cos(phi0 + phi)
216 // Pz = Pt * tan(lambda)
217 //
218 // E = sqrt( 1/kappa/kappa * (1+tan(lambda)*tan(lambda)) + mass*mass )
219
220 double pt = fabs(m_pt);
221 double px = - pt * sin(m_ac[1] + phi);
222 double py = pt * cos(m_ac[1] + phi);
223 double pz = pt * m_ac[4];
224 double E = sqrt(pt*pt*(1.+m_ac[4]*m_ac[4])+mass*mass);
225
226 return HepLorentzVector(px, py, pz, E);
227}
228
229
230HepLorentzVector
231VFHelix::momentum(double phi, double mass, HepSymMatrix & Em) const {
232 //
233 // Calculate momentum.
234 //
235 // Pt = | 1/kappa | (GeV/c)
236 //
237 // Px = -Pt * sin(phi0 + phi)
238 // Py = Pt * cos(phi0 + phi)
239 // Pz = Pt * tan(lambda)
240 //
241 // E = sqrt( 1/kappa/kappa * (1+tan(lambda)*tan(lambda)) + mass*mass )
242
243 double pt = fabs(m_pt);
244 double px = - pt * sin(m_ac[1] + phi);
245 double py = pt * cos(m_ac[1] + phi);
246 double pz = pt * m_ac[4];
247 double E = sqrt(pt*pt*(1.+m_ac[4]*m_ac[4])+mass*mass);
248
249 if (m_matrixValid) Em = m_Ea.similarity(del4MDelA(phi,mass));
250 else Em = m_Ea;
251
252 return HepLorentzVector(px, py, pz, E);
253}
254
255HepLorentzVector
257 double mass,
258 HepPoint3D & x,
259 HepSymMatrix & Emx) const {
260 //
261 // Calculate momentum.
262 //
263 // Pt = | 1/kappa | (GeV/c)
264 //
265 // Px = -Pt * sin(phi0 + phi)
266 // Py = Pt * cos(phi0 + phi)
267 // Pz = Pt * tan(lambda)
268 //
269 // E = sqrt( 1/kappa/kappa * (1+tan(lambda)*tan(lambda)) + mass*mass )
270
271 double pt = fabs(m_pt);
272 double px = - pt * sin(m_ac[1] + phi);
273 double py = pt * cos(m_ac[1] + phi);
274 double pz = pt * m_ac[4];
275 double E = sqrt(pt * pt * (1. + m_ac[4] * m_ac[4]) + mass * mass);
276
277 x.setX(m_pivot.x() + m_ac[0] * m_cp + m_r * (m_cp - cos(m_ac[1] + phi)));
278 x.setY(m_pivot.y() + m_ac[0] * m_sp + m_r * (m_sp - sin(m_ac[1] + phi)));
279 x.setZ(m_pivot.z() + m_ac[3] - m_r * m_ac[4] * phi);
280
281 if (m_matrixValid) Emx = m_Ea.similarity(del4MXDelA(phi,mass));
282 else Emx = m_Ea;
283
284 return HepLorentzVector(px, py, pz, E);
285}
286
287
288const HepPoint3D &
289VFHelix::pivot(const HepPoint3D & newPivot) {
290 const double & dr = m_ac[0];
291 const double & phi0 = m_ac[1];
292 const double & kappa = m_ac[2];
293 const double & dz = m_ac[3];
294 const double & tanl = m_ac[4];
295
296 double rdr = dr + m_r;
297 double phi = fmod(phi0 + M_PI4, M_PI2);
298 double csf0 = cos(phi);
299 double snf0 = (1. - csf0) * (1. + csf0);
300 snf0 = sqrt((snf0 > 0.) ? snf0 : 0.);
301 if(phi > M_PI) snf0 = - snf0;
302
303 double xc = m_pivot.x() + rdr * csf0;
304 double yc = m_pivot.y() + rdr * snf0;
305 double csf, snf;
306 if(m_r != 0.0) {
307 csf = (xc - newPivot.x()) / m_r;
308 snf = (yc - newPivot.y()) / m_r;
309 double anrm = sqrt(csf * csf + snf * snf);
310 if(anrm != 0.0) {
311 csf /= anrm;
312 snf /= anrm;
313 phi = atan2(snf, csf);
314 } else {
315 csf = 1.0;
316 snf = 0.0;
317 phi = 0.0;
318 }
319 } else {
320 csf = 1.0;
321 snf = 0.0;
322 phi = 0.0;
323 }
324 double phid = fmod(phi - phi0 + M_PI8, M_PI2);
325 if(phid > M_PI) phid = phid - M_PI2;
326 double drp = (m_pivot.x() + dr * csf0 + m_r * (csf0 - csf) - newPivot.x())
327 * csf
328 + (m_pivot.y() + dr * snf0 + m_r * (snf0 - snf) - newPivot.y()) * snf;
329 double dzp = m_pivot.z() + dz - m_r * tanl * phid - newPivot.z();
330
331 HepVector ap(5);
332 ap[0] = drp;
333 ap[1] = fmod(phi + M_PI4, M_PI2);
334 ap[2] = kappa;
335 ap[3] = dzp;
336 ap[4] = tanl;
337
338 // if (m_matrixValid) m_Ea.assign(delApDelA(ap) * m_Ea * delApDelA(ap).T());
339 if (m_matrixValid) m_Ea = m_Ea.similarity(delApDelA(ap));
340
341 m_a = ap;
342 m_pivot = newPivot;
343
344 //...Are these needed?...iw...
345 updateCache();
346 return m_pivot;
347}
348
349void
351 const HepVector & a,
352 const HepSymMatrix & Ea) {
353 m_pivot = pivot;
354 m_a = a;
355 m_Ea = Ea;
356 m_matrixValid = true;
357 updateCache();
358}
359
360VFHelix &
362 if (this == & i) return * this;
363
364 m_bField = i.m_bField;
365 m_alpha = i.m_alpha;
366 m_pivot = i.m_pivot;
367 m_a = i.m_a;
368 m_Ea = i.m_Ea;
369 m_matrixValid = i.m_matrixValid;
370
371 m_center = i.m_center;
372 m_cp = i.m_cp;
373 m_sp = i.m_sp;
374 m_pt = i.m_pt;
375 m_r = i.m_r;
376 m_ac[0] = i.m_ac[0];
377 m_ac[1] = i.m_ac[1];
378 m_ac[2] = i.m_ac[2];
379 m_ac[3] = i.m_ac[3];
380 m_ac[4] = i.m_ac[4];
381
382 return * this;
383}
384
385void
386VFHelix::updateCache(void) {
387 //
388 // Calculate VFHelix center( xc, yc ).
389 //
390 // xc = x0 + (dr + (alpha / kappa)) * cos(phi0) (cm)
391 // yc = y0 + (dr + (alpha / kappa)) * sin(phi0) (cm)
392 //
393
394 m_ac[0] = m_a[0];
395 m_ac[1] = m_a[1];
396 m_ac[2] = m_a[2];
397 m_ac[3] = m_a[3];
398 m_ac[4] = m_a[4];
399
400 m_cp = cos(m_ac[1]);
401 m_sp = sin(m_ac[1]);
402 if (m_ac[2] != 0.0) {
403 m_pt = 1. / m_ac[2];
404 m_r = m_alpha / m_ac[2];
405 }
406 else {
407 m_pt = (DBL_MAX);
408 m_r = (DBL_MAX);
409 }
410
411 double x = m_pivot.x() + (m_ac[0] + m_r) * m_cp;
412 double y = m_pivot.y() + (m_ac[0] + m_r) * m_sp;
413 m_center.setX(x);
414 m_center.setY(y);
415 m_center.setZ(0.);
416}
417
418HepMatrix
419VFHelix::delApDelA(const HepVector & ap) const {
420 //
421 // Calculate Jacobian (@ap/@a)
422 // Vector ap is new helix parameters and a is old helix parameters.
423 //
424
425 HepMatrix dApDA(5,5,0);
426
427 const double & dr = m_ac[0];
428 const double & phi0 = m_ac[1];
429 const double & cpa = m_ac[2];
430 const double & dz = m_ac[3];
431 const double & tnl = m_ac[4];
432
433 double drp = ap[0];
434 double phi0p = ap[1];
435 double cpap = ap[2];
436 double dzp = ap[3];
437 double tnlp = ap[4];
438
439 double rdr = m_r + dr;
440 double rdrpr;
441 if ((m_r + drp) != 0.0) {
442 rdrpr = 1. / (m_r + drp);
443 } else {
444 rdrpr = (DBL_MAX);
445 }
446 // double csfd = cos(phi0)*cos(phi0p) + sin(phi0)*sin(phi0p);
447 // double snfd = cos(phi0)*sin(phi0p) - sin(phi0)*cos(phi0p);
448 double csfd = cos(phi0p - phi0);
449 double snfd = sin(phi0p - phi0);
450 double phid = fmod(phi0p - phi0 + M_PI8, M_PI2);
451 if (phid > M_PI) phid = phid - M_PI2;
452
453 dApDA[0][0] = csfd;
454 dApDA[0][1] = rdr*snfd;
455 if(cpa!=0.0) {
456 dApDA[0][2] = (m_r/cpa)*( 1.0 - csfd );
457 } else {
458 dApDA[0][2] = (DBL_MAX);
459 }
460
461 dApDA[1][0] = - rdrpr*snfd;
462 dApDA[1][1] = rdr*rdrpr*csfd;
463 if(cpa!=0.0) {
464 dApDA[1][2] = (m_r/cpa)*rdrpr*snfd;
465 } else {
466 dApDA[1][2] = (DBL_MAX);
467 }
468
469 dApDA[2][2] = 1.0;
470
471 dApDA[3][0] = m_r*rdrpr*tnl*snfd;
472 dApDA[3][1] = m_r*tnl*(1.0 - rdr*rdrpr*csfd);
473 if(cpa!=0.0) {
474 dApDA[3][2] = (m_r/cpa)*tnl*(phid - m_r*rdrpr*snfd);
475 } else {
476 dApDA[3][2] = (DBL_MAX);
477 }
478 dApDA[3][3] = 1.0;
479 dApDA[3][4] = - m_r*phid;
480
481 dApDA[4][4] = 1.0;
482
483 return dApDA;
484}
485
486HepMatrix
487VFHelix::delXDelA(double phi) const {
488 //
489 // Calculate Jacobian (@x/@a)
490 // Vector a is helix parameters and phi is internal parameter
491 // which specifys the point to be calculated for Ex(phi).
492 //
493
494 HepMatrix dXDA(3,5,0);
495
496 const double & dr = m_ac[0];
497 const double & phi0 = m_ac[1];
498 const double & cpa = m_ac[2];
499 const double & dz = m_ac[3];
500 const double & tnl = m_ac[4];
501
502 double cosf0phi = cos(phi0 + phi);
503 double sinf0phi = sin(phi0 + phi);
504
505 dXDA[0][0] = m_cp;
506 dXDA[0][1] = - dr * m_sp + m_r * (- m_sp + sinf0phi);
507 if(cpa!=0.0) {
508 dXDA[0][2] = - (m_r / cpa) * (m_cp - cosf0phi);
509 } else {
510 dXDA[0][2] = (DBL_MAX);
511 }
512 // dXDA[0][3] = 0.0;
513 // dXDA[0][4] = 0.0;
514
515 dXDA[1][0] = m_sp;
516 dXDA[1][1] = dr * m_cp + m_r * (m_cp - cosf0phi);
517 if(cpa!=0.0) {
518 dXDA[1][2] = - (m_r / cpa) * (m_sp - sinf0phi);
519 } else {
520 dXDA[1][2] = (DBL_MAX);
521 }
522 // dXDA[1][3] = 0.0;
523 // dXDA[1][4] = 0.0;
524
525 // dXDA[2][0] = 0.0;
526 // dXDA[2][1] = 0.0;
527 if(cpa!=0.0) {
528 dXDA[2][2] = (m_r / cpa) * tnl * phi;
529 } else {
530 dXDA[2][2] = (DBL_MAX);
531 }
532 dXDA[2][3] = 1.0;
533 dXDA[2][4] = - m_r * phi;
534
535 return dXDA;
536}
537
538
539
540HepMatrix
541VFHelix::delMDelA(double phi) const {
542 //
543 // Calculate Jacobian (@m/@a)
544 // Vector a is helix parameters and phi is internal parameter.
545 // Vector m is momentum.
546 //
547
548 HepMatrix dMDA(3,5,0);
549
550 const double & phi0 = m_ac[1];
551 const double & cpa = m_ac[2];
552 const double & tnl = m_ac[4];
553
554 double cosf0phi = cos(phi0+phi);
555 double sinf0phi = sin(phi0+phi);
556
557 double rho;
558 if(cpa != 0.)rho = 1./cpa;
559 else rho = (DBL_MAX);
560
561 double charge = 1.;
562 if(cpa < 0.)charge = -1.;
563
564 dMDA[0][1] = -fabs(rho)*cosf0phi;
565 dMDA[0][2] = charge*rho*rho*sinf0phi;
566
567 dMDA[1][1] = -fabs(rho)*sinf0phi;
568 dMDA[1][2] = -charge*rho*rho*cosf0phi;
569
570 dMDA[2][2] = -charge*rho*rho*tnl;
571 dMDA[2][4] = fabs(rho);
572
573 return dMDA;
574}
575
576
577HepMatrix
578VFHelix::del4MDelA(double phi, double mass) const {
579 //
580 // Calculate Jacobian (@4m/@a)
581 // Vector a is helix parameters and phi is internal parameter.
582 // Vector 4m is 4 momentum.
583 //
584
585 HepMatrix d4MDA(4,5,0);
586
587 double phi0 = m_ac[1];
588 double cpa = m_ac[2];
589 double tnl = m_ac[4];
590
591 double cosf0phi = cos(phi0+phi);
592 double sinf0phi = sin(phi0+phi);
593
594 double rho;
595 if(cpa != 0.)rho = 1./cpa;
596 else rho = (DBL_MAX);
597
598 double charge = 1.;
599 if(cpa < 0.)charge = -1.;
600
601 double E = sqrt(rho*rho*(1.+tnl*tnl)+mass*mass);
602
603 d4MDA[0][1] = -fabs(rho)*cosf0phi;
604 d4MDA[0][2] = charge*rho*rho*sinf0phi;
605
606 d4MDA[1][1] = -fabs(rho)*sinf0phi;
607 d4MDA[1][2] = -charge*rho*rho*cosf0phi;
608
609 d4MDA[2][2] = -charge*rho*rho*tnl;
610 d4MDA[2][4] = fabs(rho);
611
612 if (cpa != 0.0 && E != 0.0) {
613 d4MDA[3][2] = (-1.-tnl*tnl)/(cpa*cpa*cpa*E);
614 d4MDA[3][4] = tnl/(cpa*cpa*E);
615 } else {
616 d4MDA[3][2] = (DBL_MAX);
617 d4MDA[3][4] = (DBL_MAX);
618 }
619 return d4MDA;
620}
621
622
623HepMatrix
624VFHelix::del4MXDelA(double phi, double mass) const {
625 //
626 // Calculate Jacobian (@4mx/@a)
627 // Vector a is helix parameters and phi is internal parameter.
628 // Vector 4xm is 4 momentum and position.
629 //
630
631 HepMatrix d4MXDA(7,5,0);
632
633 const double & dr = m_ac[0];
634 const double & phi0 = m_ac[1];
635 const double & cpa = m_ac[2];
636 const double & dz = m_ac[3];
637 const double & tnl = m_ac[4];
638
639 double cosf0phi = cos(phi0+phi);
640 double sinf0phi = sin(phi0+phi);
641
642 double rho;
643 if(cpa != 0.)rho = 1./cpa;
644 else rho = (DBL_MAX);
645
646 double charge = 1.;
647 if(cpa < 0.)charge = -1.;
648
649 double E = sqrt(rho * rho * (1. + tnl * tnl) + mass * mass);
650
651 d4MXDA[0][1] = - fabs(rho) * cosf0phi;
652 d4MXDA[0][2] = charge * rho * rho * sinf0phi;
653
654 d4MXDA[1][1] = - fabs(rho) * sinf0phi;
655 d4MXDA[1][2] = - charge * rho * rho * cosf0phi;
656
657 d4MXDA[2][2] = - charge * rho * rho * tnl;
658 d4MXDA[2][4] = fabs(rho);
659
660 if (cpa != 0.0 && E != 0.0) {
661 d4MXDA[3][2] = (- 1. - tnl * tnl) / (cpa * cpa * cpa * E);
662 d4MXDA[3][4] = tnl / (cpa * cpa * E);
663 } else {
664 d4MXDA[3][2] = (DBL_MAX);
665 d4MXDA[3][4] = (DBL_MAX);
666 }
667
668 d4MXDA[4][0] = m_cp;
669 d4MXDA[4][1] = - dr * m_sp + m_r * (- m_sp + sinf0phi);
670 if (cpa != 0.0) {
671 d4MXDA[4][2] = - (m_r / cpa) * (m_cp - cosf0phi);
672 } else {
673 d4MXDA[4][2] = (DBL_MAX);
674 }
675
676 d4MXDA[5][0] = m_sp;
677 d4MXDA[5][1] = dr * m_cp + m_r * (m_cp - cosf0phi);
678 if (cpa != 0.0) {
679 d4MXDA[5][2] = - (m_r / cpa) * (m_sp - sinf0phi);
680
681 d4MXDA[6][2] = (m_r / cpa) * tnl * phi;
682 } else {
683 d4MXDA[5][2] = (DBL_MAX);
684
685 d4MXDA[6][2] = (DBL_MAX);
686 }
687
688 d4MXDA[6][3] = 1.;
689 d4MXDA[6][4] = - m_r * phi;
690
691 return d4MXDA;
692}
693
694void
696 m_matrixValid = false;
697 m_Ea *= 0.;
698}
HepGeom::Point3D< double > HepPoint3D
double sin(const BesAngle a)
Definition: BesAngle.h:210
double cos(const BesAngle a)
Definition: BesAngle.h:213
**********INTEGER nmxhep !maximum number of particles DOUBLE PRECISION vhep INTEGER jdahep COMMON hepevt $ !serial number $ !number of particles $ !status code $ !particle ident KF $ !parent particles $ !childreen particles $ !four momentum
double mass
#define DBL_MAX
Definition: KalFitAlg.h:13
#define M_PI
Definition: TConstant.h:4
static const double ConstantAlpha
Constant alpha for uniform field.
HepMatrix del4MDelA(double phi, double mass) const
const HepPoint3D & pivot(void) const
returns pivot position.
HepPoint3D x(double dPhi=0.) const
returns position after rotating angle dPhi in phi direction.
HepMatrix delApDelA(const HepVector &ap) const
double dr(void) const
returns an element of parameters.
HepMatrix delMDelA(double phi) const
HepMatrix del4MXDelA(double phi, double mass) const
Hep3Vector momentum(double dPhi=0.) const
returns momentum vector after rotating angle dPhi in phi direction.
HepMatrix delXDelA(double phi) const
void ignoreErrorMatrix(void)
unsets error matrix. Error calculations will be ignored after this function call until an error matri...
void set(const HepPoint3D &pivot, const HepVector &a, const HepSymMatrix &Ea)
sets helix pivot position, parameters, and error matrix.
VFHelix & operator=(const VFHelix &)
Copy operator.
VFHelix(const HepPoint3D &pivot, const HepVector &a, const HepSymMatrix &Ea)
Constructor with pivot, helix parameter a, and its error matrix.
const HepSymMatrix & Ea(void) const
returns error matrix.
const HepVector & a(void) const
returns helix parameters.
double y[1000]
double x[1000]
float charge