]>
Commit | Line | Data |
---|---|---|
4c039060 | 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 | **************************************************************************/ | |
15 | ||
f531a546 | 16 | // $Id$ |
4c039060 | 17 | |
959fbac5 | 18 | /////////////////////////////////////////////////////////////////////////// |
19 | // Class Ali4Vector | |
20 | // Handling of Lorentz 4-vectors in various reference frames. | |
21 | // | |
22 | // This class is meant to serve as a base class for ALICE objects | |
23 | // that have Lorentz 4-vector characteristics. | |
24 | // Error propagation is performed automatically. | |
25 | // | |
26 | // All 4-vectors are treated in the contravariant form and the convention | |
27 | // for the metric and the 4-vector components is according to the one | |
28 | // used in the book "Classical Electrodynamics" by J.D. Jackson. | |
29 | // | |
30 | // A 4-vector is said to have a scalar part and a 3-vector part, | |
31 | // which is indicated by the notation | |
32 | // | |
33 | // x^i = (x^0,x^1,x^2,x^3) | |
34 | // | |
35 | // The scalar part = x^0 | |
36 | // The 3-vector part = (x^1,x^2,x^3) | |
37 | // | |
38 | // In view of accuracy and the fact that e.g. particle identity (mass) | |
39 | // is preserved in many physics processes, the Lorentz invariant | |
40 | // (x^i*x_i) is internally saved together with the scalar part. | |
41 | // | |
42 | // This allows the following two modes of functionality : | |
43 | // | |
44 | // Scalar mode : The scalar part and the 3-vector part are considered | |
45 | // as basic quantities and the invariant with its error | |
46 | // is derived from these. | |
47 | // Invariant mode : The invariant and the 3-vector part are considered | |
48 | // as basic quantities and the scalar with its error | |
49 | // is derived from these. | |
50 | // | |
51 | // The philosophy followed here is the following : | |
52 | // =============================================== | |
53 | // | |
54 | // 1) Invokation of SetVector() sets the scalar and 3-vector parts | |
55 | // and the invariant is calculated from these. | |
56 | // Automatically the scalar mode is selected and invokation of | |
57 | // SetErrors() will calculate the error on the invariant. | |
58 | // | |
59 | // 2) In case the scalar part is modified via SetScalar(), scalar mode is | |
60 | // automatically selected and the Lorentz invariant (x^i*x_i) and its | |
61 | // error are updated accordingly. | |
62 | // The 3-vector part is NOT modified. | |
63 | // This situation arises when one e.g. precisely determines the time | |
64 | // or energy (x^0). | |
65 | // | |
66 | // 3) In case the Lorentz invariant (x^i*x_i) is modified via SetInvariant(), | |
67 | // invariant mode is selected automatically and the scalar part and its | |
68 | // error are updated accordingly. | |
69 | // The 3-vector part is NOT modified. | |
70 | // This situation arises when one e.g. precisely determines the mass. | |
71 | // | |
72 | // 4) In case the vector part is modified via Set3Vector(), then the | |
73 | // current mode determines whether the scalar or the invariant is updated. | |
74 | // Scalar mode : The Lorentz invariant (x^i*x_i) and its error are updated; | |
75 | // the scalar part and its error are NOT modified. | |
76 | // This situation arises when one e.g. improves the 3-position | |
77 | // vector for a particle with a very precise timing. | |
78 | // Invariant mode : The scalar part and its error are updated; | |
79 | // the Lorentz invariant (x^i*x_i) and its error are NOT modified. | |
80 | // This situation arises when one e.g. improves the 3-momentum | |
81 | // vector for a particle with known mass. | |
82 | // | |
83 | // The dotproduct is defined such that p.Dot(p) yields the Lorentz invariant | |
84 | // scalar of the 4-vector p (i.e. m**2 in case p is a 4-momentum). | |
85 | // | |
86 | // Note : | |
87 | // ------ | |
88 | // Vectors (v), Errors (e) and reference frames (f) are specified via | |
89 | // SetVector(Float_t* v,TString f) | |
90 | // SetErrors(Float_t* e,TString f) | |
91 | // under the following conventions : | |
92 | // | |
93 | // f="car" ==> 3-vector part of v in Cartesian coordinates (x,y,z) | |
94 | // f="sph" ==> 3-vector part of v in Spherical coordinates (r,theta,phi) | |
95 | // f="cyl" ==> 3-vector part of v in Cylindrical coordinates (rho,phi,z) | |
96 | // | |
97 | // All angles are in radians. | |
98 | // | |
99 | // Example : | |
100 | // --------- | |
101 | // | |
102 | // Ali4Vector a; | |
103 | // | |
104 | // Float_t v[4]={25,-1,3,7}; | |
105 | // a.SetVector(v,"car"); | |
106 | // | |
107 | // Float_t vec[4]; | |
108 | // a.GetVector(vec,"sph"); | |
109 | // | |
110 | // Ali4Vector b; | |
111 | // Float_t v2[4]={33,6,-18,2}; | |
112 | // b.SetVector(v2,"car"); | |
113 | // | |
114 | // Float_t dotpro=a.Dot(b); | |
115 | // | |
116 | // Float_t x0=16; | |
117 | // Ali3Vector x; | |
118 | // Float_t vec2[3]={1,2,3}; | |
119 | // x.SetVector(vec2,"car"); | |
120 | // | |
121 | // Ali4Vector c; | |
122 | // c.SetVector(x0,x); | |
123 | // c.GetVector(vec,"car"); | |
124 | // c.Info("cyl"); | |
125 | // c=a+b; | |
126 | // c=a-b; | |
127 | // c=a*5; | |
128 | // | |
129 | //--- Author: Nick van Eijndhoven 01-apr-1999 UU-SAP Utrecht | |
f531a546 | 130 | //- Modified: NvE $Date$ UU-SAP Utrecht |
959fbac5 | 131 | /////////////////////////////////////////////////////////////////////////// |
132 | ||
d88f97cc | 133 | #include "Ali4Vector.h" |
134 | ||
135 | ClassImp(Ali4Vector) // Class implementation to enable ROOT I/O | |
136 | ||
137 | Ali4Vector::Ali4Vector() | |
138 | { | |
959fbac5 | 139 | // Creation of a contravariant 4-vector and initialisation of parameters. |
140 | // All values are initialised to 0. | |
141 | // Scalar mode is initially selected. | |
142 | fScalar=1; | |
143 | fV2=0; | |
144 | fDv2=0; | |
d88f97cc | 145 | fV0=0; |
959fbac5 | 146 | fDv0=0; |
147 | fDresult=0; | |
d88f97cc | 148 | Double_t a[3]={0,0,0}; |
149 | fV.SetVector(a,"sph"); | |
150 | } | |
151 | /////////////////////////////////////////////////////////////////////////// | |
152 | Ali4Vector::~Ali4Vector() | |
153 | { | |
154 | // Destructor to delete dynamically allocated memory | |
155 | } | |
156 | /////////////////////////////////////////////////////////////////////////// | |
157 | void Ali4Vector::SetVector(Double_t v0,Ali3Vector v) | |
158 | { | |
959fbac5 | 159 | // Store contravariant vector. |
160 | // The error on the scalar part is initialised to 0. | |
161 | // The errors on the vector part are taken from the input Ali3Vector. | |
162 | // Scalar mode is automatically selected. | |
163 | // The error on scalar result operations is reset to 0. | |
164 | fScalar=1; | |
d88f97cc | 165 | fV0=v0; |
166 | fV=v; | |
959fbac5 | 167 | fV2=pow(v0,2)-fV.Dot(fV); |
168 | SetScalarError(0); | |
d88f97cc | 169 | } |
170 | /////////////////////////////////////////////////////////////////////////// | |
171 | void Ali4Vector::SetVector(Double_t* v,TString f) | |
172 | { | |
959fbac5 | 173 | // Store vector according to reference frame f. |
174 | // All errors are initialised to 0. | |
175 | // Scalar mode is automatically selected. | |
176 | // The error on scalar result operations is reset to 0. | |
177 | fScalar=1; | |
d88f97cc | 178 | Double_t a[3]; |
179 | for (Int_t i=0; i<3; i++) | |
180 | { | |
181 | a[i]=v[i+1]; | |
182 | } | |
959fbac5 | 183 | fV0=v[0]; |
d88f97cc | 184 | fV.SetVector(a,f); |
959fbac5 | 185 | fV2=pow(fV0,2)-fV.Dot(fV); |
186 | fDv2=0; | |
187 | fDv0=0; | |
188 | fDresult=0; | |
d88f97cc | 189 | } |
190 | /////////////////////////////////////////////////////////////////////////// | |
191 | void Ali4Vector::GetVector(Double_t* v,TString f) | |
192 | { | |
959fbac5 | 193 | // Provide 4-vector components according to reference frame f |
194 | // and according to the current mode. | |
195 | // Scalar mode : The scalar part is directly returned via v[0]. | |
196 | // Invariant mode : The scalar part is re-calculated via the value | |
197 | // of the Lorentz invariant and then returned via v[0]. | |
198 | if (fScalar) | |
199 | { | |
200 | v[0]=fV0; | |
201 | } | |
202 | else | |
203 | { | |
204 | v[0]=sqrt(fV.Dot(fV)+fV2); | |
205 | } | |
d88f97cc | 206 | Double_t a[3]; |
207 | fV.GetVector(a,f); | |
208 | for (Int_t i=0; i<3; i++) | |
209 | { | |
210 | v[i+1]=a[i]; | |
211 | } | |
212 | } | |
213 | /////////////////////////////////////////////////////////////////////////// | |
214 | void Ali4Vector::SetVector(Float_t* v,TString f) | |
215 | { | |
959fbac5 | 216 | // Store vector according to reference frame f. |
217 | // All errors are initialised to 0. | |
218 | // Scalar mode is automatically selected. | |
219 | // The error on scalar result operations is reset to 0. | |
d88f97cc | 220 | Double_t vec[4]; |
221 | for (Int_t i=0; i<4; i++) | |
222 | { | |
223 | vec[i]=v[i]; | |
224 | } | |
225 | SetVector(vec,f); | |
226 | } | |
227 | /////////////////////////////////////////////////////////////////////////// | |
228 | void Ali4Vector::GetVector(Float_t* v,TString f) | |
229 | { | |
959fbac5 | 230 | // Provide 4-vector components according to reference frame f |
231 | // and according to the current mode. | |
232 | // Scalar mode : The scalar part is directly returned via v[0]. | |
233 | // Invariant mode : The scalar part is re-calculated via the value | |
234 | // of the Lorentz invariant and then returned via v[0]. | |
d88f97cc | 235 | Double_t vec[4]; |
236 | GetVector(vec,f); | |
237 | for (Int_t i=0; i<4; i++) | |
238 | { | |
239 | v[i]=vec[i]; | |
240 | } | |
241 | } | |
242 | /////////////////////////////////////////////////////////////////////////// | |
243 | Double_t Ali4Vector::GetScalar() | |
244 | { | |
959fbac5 | 245 | // Provide the scalar part. |
246 | // The error on the scalar value is available via GetResultError() | |
247 | // after invokation of GetScalar(). | |
248 | if (fScalar) | |
249 | { | |
250 | fDresult=fDv0; | |
251 | return fV0; | |
252 | } | |
253 | else | |
254 | { | |
255 | Double_t dot=fV.Dot(fV); | |
256 | Double_t ddot=fV.GetResultError(); | |
257 | Double_t v02=dot+fV2; | |
258 | Double_t dv02=sqrt(pow(ddot,2)+pow(fDv2,2)); | |
259 | Double_t v0=sqrt(fabs(v02)); | |
260 | Double_t dv0=0; | |
261 | if (v0) dv0=dv02/(2.*v0); | |
262 | fDresult=dv0; | |
263 | return v0; | |
264 | } | |
265 | } | |
266 | /////////////////////////////////////////////////////////////////////////// | |
267 | Double_t Ali4Vector::GetResultError() | |
268 | { | |
269 | // Provide the error on the result of an operation yielding a scalar | |
270 | // E.g. GetScalar(), GetInvariant() or Dot() | |
271 | return fDresult; | |
272 | } | |
273 | /////////////////////////////////////////////////////////////////////////// | |
274 | void Ali4Vector::SetScalar(Double_t v0,Double_t dv0) | |
275 | { | |
276 | // Modify the scalar part (v0) and its error (dv0). | |
277 | // The default value for dv0 is 0. | |
278 | // The vector part is not modified. | |
279 | // Scalar mode is automatically selected | |
280 | // ==> Lorentz invariant and its error are updated. | |
281 | // The error on scalar result operations is reset to 0. | |
282 | fScalar=1; | |
283 | fV0=v0; | |
284 | fV2=pow(v0,2)-fV.Dot(fV); | |
285 | SetScalarError(dv0); | |
286 | } | |
287 | /////////////////////////////////////////////////////////////////////////// | |
288 | void Ali4Vector::SetScalarError(Double_t dv0) | |
289 | { | |
290 | // Set the error on the scalar part. | |
291 | // If in scalar mode, update error on the invariant accordingly. | |
292 | // The error on scalar result operations is reset to 0. | |
293 | fDv0=dv0; | |
294 | if (fScalar) | |
295 | { | |
296 | Double_t norm=fV.GetNorm(); | |
297 | Double_t dnorm=fV.GetResultError(); | |
298 | fDv2=sqrt(pow(2.*fV0*fDv0,2)+pow(2.*norm*dnorm,2)); | |
299 | } | |
300 | fDresult=0; | |
301 | } | |
302 | /////////////////////////////////////////////////////////////////////////// | |
303 | void Ali4Vector::Set3Vector(Ali3Vector v) | |
304 | { | |
305 | // Set the 3-vector part, the errors are taken from the input Ali3Vector | |
306 | // Scalar mode : The scalar part and its error are not modified, | |
307 | // the Lorentz invariantand its error are re-calculated. | |
308 | // Invariant mode : The Lorentz invariant and its error are not modified, | |
309 | // the scalar part and its error are re-calculated. | |
310 | // The error on scalar result operations is reset to 0. | |
311 | fV=v; | |
312 | if (fScalar) | |
313 | { | |
314 | SetScalar(fV0,fDv0); | |
315 | } | |
316 | else | |
317 | { | |
318 | SetInvariant(fV2,fDv2); | |
319 | } | |
320 | } | |
321 | /////////////////////////////////////////////////////////////////////////// | |
322 | void Ali4Vector::Set3Vector(Double_t* v,TString f) | |
323 | { | |
324 | // Set the 3-vector part according to reference frame f | |
325 | // The errors on the vector part are initialised to 0 | |
326 | // Scalar mode : The scalar part and its error are not modified, | |
327 | // the Lorentz invariantand its error are re-calculated. | |
328 | // Invariant mode : The Lorentz invariant and its error are not modified, | |
329 | // the scalar part and its error are re-calculated. | |
330 | // The error on scalar result operations is reset to 0. | |
331 | Double_t a[3]; | |
332 | for (Int_t i=0; i<3; i++) | |
333 | { | |
334 | a[i]=v[i]; | |
335 | } | |
336 | fV.SetVector(a,f); | |
337 | ||
338 | if (fScalar) | |
339 | { | |
340 | SetScalar(fV0,fDv0); | |
341 | } | |
342 | else | |
343 | { | |
344 | SetInvariant(fV2,fDv2); | |
345 | } | |
346 | } | |
347 | /////////////////////////////////////////////////////////////////////////// | |
348 | void Ali4Vector::Set3Vector(Float_t* v,TString f) | |
349 | { | |
350 | // Set the 3-vector part according to reference frame f | |
351 | // The errors on the vector part are initialised to 0 | |
352 | // The Lorentz invariant is not modified | |
353 | // The error on scalar result operations is reset to 0. | |
354 | Double_t vec[3]; | |
355 | for (Int_t i=0; i<3; i++) | |
356 | { | |
357 | vec[i]=v[i]; | |
358 | } | |
359 | Set3Vector(vec,f); | |
360 | } | |
361 | /////////////////////////////////////////////////////////////////////////// | |
362 | void Ali4Vector::SetInvariant(Double_t v2,Double_t dv2) | |
363 | { | |
364 | // Modify the Lorentz invariant (v2) quantity v^i*v_i and its error (dv2). | |
365 | // The default value for the error dv2 is 0. | |
366 | // The vector part is not modified. | |
367 | // Invariant mode is automatically selected | |
368 | // ==> the scalar part and its error are updated. | |
369 | // The error on scalar result operations is reset to 0. | |
370 | // | |
371 | fScalar=0; | |
372 | fV2=v2; | |
373 | fDv2=dv2; | |
374 | fV0=GetScalar(); | |
375 | fDv0=GetResultError(); | |
376 | fDresult=0; | |
377 | } | |
378 | /////////////////////////////////////////////////////////////////////////// | |
379 | void Ali4Vector::SetInvariantError(Double_t dv2) | |
380 | { | |
381 | // Set the error on the Lorentz invariant. | |
382 | // If in invariant mode, update error on the scalar part accordingly. | |
383 | // The error on scalar result operations is reset to 0. | |
384 | fDv2=dv2; | |
385 | if (!fScalar) | |
386 | { | |
387 | fDv0=GetResultError(); | |
388 | } | |
389 | fDresult=0; | |
390 | } | |
391 | /////////////////////////////////////////////////////////////////////////// | |
392 | Double_t Ali4Vector::GetInvariant() | |
393 | { | |
394 | // Provide the Lorentz invariant v^i*v_i. | |
395 | // The error on the Lorentz invariant is available via GetResultError() | |
396 | // after invokation of GetInvariant(). | |
397 | if (!fScalar) | |
398 | { | |
399 | fDresult=fDv2; | |
400 | return fV2; | |
401 | } | |
402 | else | |
403 | { | |
404 | Double_t inv=Dot(*this); | |
405 | return inv; | |
406 | } | |
d88f97cc | 407 | } |
408 | /////////////////////////////////////////////////////////////////////////// | |
409 | Ali3Vector Ali4Vector::Get3Vector() | |
410 | { | |
411 | // Provide the 3-vector part | |
412 | return fV; | |
413 | } | |
414 | /////////////////////////////////////////////////////////////////////////// | |
959fbac5 | 415 | void Ali4Vector::SetErrors(Double_t* e,TString f) |
416 | { | |
417 | // Store errors for vector v^i according to reference frame f | |
418 | // If in scalar mode, update error on the invariant accordingly. | |
419 | // The error on scalar result operations is reset to 0. | |
420 | Double_t a[3]; | |
421 | for (Int_t i=0; i<3; i++) | |
422 | { | |
423 | a[i]=e[i+1]; | |
424 | } | |
425 | SetScalarError(e[0]); | |
426 | fV.SetErrors(a,f); | |
427 | } | |
428 | /////////////////////////////////////////////////////////////////////////// | |
429 | void Ali4Vector::SetErrors(Float_t* e,TString f) | |
430 | { | |
431 | // Store errors for vector v^i according to reference frame f | |
432 | // If in scalar mode, update error on the invariant accordingly. | |
433 | // The error on scalar result operations is reset to 0. | |
434 | Double_t a[4]; | |
435 | for (Int_t i=0; i<4; i++) | |
436 | { | |
437 | a[i]=e[i]; | |
438 | } | |
439 | SetErrors(a,f); | |
440 | } | |
441 | /////////////////////////////////////////////////////////////////////////// | |
442 | void Ali4Vector::GetErrors(Double_t* e,TString f) | |
443 | { | |
444 | // Provide errors for vector v^i according to reference frame f | |
445 | // and according to the current mode. | |
446 | // Scalar mode : The error on the scalar part is directly returned via e[0]. | |
447 | // Invariant mode : The error on the scalar part is re-calculated via the error | |
448 | // value on the Lorentz invariant and then returned via e[0]. | |
449 | Double_t a[3]; | |
450 | fV.GetErrors(a,f); | |
451 | ||
452 | e[0]=GetResultError(); | |
453 | for (Int_t i=0; i<3; i++) | |
454 | { | |
455 | e[i+1]=a[i]; | |
456 | } | |
457 | } | |
458 | /////////////////////////////////////////////////////////////////////////// | |
459 | void Ali4Vector::GetErrors(Float_t* e,TString f) | |
460 | { | |
461 | // Provide errors for vector v^i according to reference frame f | |
462 | // and according to the current mode. | |
463 | // Scalar mode : The error on the scalar part is directly returned via e[0]. | |
464 | // Invariant mode : The error on the scalar part is re-calculated via the error | |
465 | // value on the Lorentz invariant and then returned via e[0]. | |
466 | Double_t a[4]; | |
467 | GetErrors(a,f); | |
468 | for (Int_t i=0; i<4; i++) | |
469 | { | |
470 | e[i]=a[i]; | |
471 | } | |
472 | } | |
473 | /////////////////////////////////////////////////////////////////////////// | |
d88f97cc | 474 | void Ali4Vector::Info(TString f) |
475 | { | |
959fbac5 | 476 | // Print contravariant vector components and errors according to |
477 | // reference frame f and according to the current mode. | |
478 | // Scalar mode : The scalar part and its error are directly returned. | |
479 | // Invariant mode : The scalar part and its error are re-calculated via the | |
480 | // value (and error) of the Lorentz invariant. | |
481 | ||
d88f97cc | 482 | if (f=="car" || f=="sph" || f=="cyl") |
483 | { | |
959fbac5 | 484 | Double_t vec[4],err[4]; |
d88f97cc | 485 | GetVector(vec,f); |
959fbac5 | 486 | GetErrors(err,f); |
487 | Double_t inv=GetInvariant(); | |
488 | Double_t dinv=GetResultError(); | |
d88f97cc | 489 | cout << " Contravariant vector in " << f << " coordinates : " |
490 | << vec[0] << " " << vec[1] << " " << vec[2] << " " << vec[3] << endl; | |
959fbac5 | 491 | cout << " ------------- Errors in " << f << " coordinates : " |
492 | << err[0] << " " << err[1] << " " << err[2] << " " << err[3] << endl; | |
493 | cout << " --- Lorentz invariant (v^i*v_i) : " << inv << " error : " << dinv << endl; | |
d88f97cc | 494 | } |
495 | else | |
496 | { | |
497 | cout << " *Ali4Vector::Info* Unsupported frame : " << f << endl | |
498 | << " Possible frames are 'car', 'sph' and 'cyl'." << endl; | |
499 | } | |
500 | } | |
501 | /////////////////////////////////////////////////////////////////////////// | |
502 | Double_t Ali4Vector::Dot(Ali4Vector& q) | |
503 | { | |
504 | // Provide the dot product of the current vector with vector q | |
959fbac5 | 505 | Double_t dotpro=0; |
506 | Double_t a0=GetScalar(); | |
507 | Double_t da0=GetResultError(); | |
508 | if ((this) == &q) // Check for special case v.Dot(v) | |
509 | { | |
510 | Double_t norm=fV.GetNorm(); | |
511 | Double_t dnorm=fV.GetResultError(); | |
512 | dotpro=pow(a0,2)-pow(norm,2); | |
513 | fDresult=sqrt(pow(2.*a0*da0,2)+pow(2.*norm*dnorm,2)); | |
514 | } | |
515 | else | |
516 | { | |
517 | Double_t b0=q.GetScalar(); | |
518 | Double_t db0=q.GetResultError(); | |
519 | Ali3Vector b=q.Get3Vector(); | |
d88f97cc | 520 | |
959fbac5 | 521 | Double_t dot=fV.Dot(b); |
522 | Double_t ddot=fV.GetResultError(); | |
d88f97cc | 523 | |
959fbac5 | 524 | dotpro=a0*b0-dot; |
525 | ||
526 | fDresult=sqrt(pow(b0*da0,2)+pow(a0*db0,2)+pow(ddot,2)); | |
d88f97cc | 527 | } |
959fbac5 | 528 | |
d88f97cc | 529 | return dotpro; |
530 | } | |
531 | /////////////////////////////////////////////////////////////////////////// | |
532 | Ali4Vector Ali4Vector::operator+(Ali4Vector& q) | |
533 | { | |
959fbac5 | 534 | // Add 4-vector q to the current 4-vector |
535 | // Error propagation is performed automatically | |
536 | Double_t a0=GetScalar(); | |
537 | Double_t da0=GetResultError(); | |
538 | Ali3Vector a=Get3Vector(); | |
539 | Double_t b0=q.GetScalar(); | |
540 | Double_t db0=q.GetResultError(); | |
541 | Ali3Vector b=q.Get3Vector(); | |
d88f97cc | 542 | |
959fbac5 | 543 | Double_t c0=a0+b0; |
544 | Ali3Vector c=a+b; | |
545 | Double_t dc0=sqrt(pow(da0,2)+pow(db0,2)); | |
d88f97cc | 546 | |
547 | Ali4Vector v; | |
959fbac5 | 548 | v.SetVector(c0,c); |
549 | v.SetScalarError(dc0); | |
d88f97cc | 550 | return v; |
551 | } | |
552 | /////////////////////////////////////////////////////////////////////////// | |
553 | Ali4Vector Ali4Vector::operator-(Ali4Vector& q) | |
554 | { | |
959fbac5 | 555 | // Subtract 4-vector q from the current 4-vector |
556 | // Error propagation is performed automatically | |
557 | Double_t a0=GetScalar(); | |
558 | Double_t da0=GetResultError(); | |
559 | Ali3Vector a=Get3Vector(); | |
560 | Double_t b0=q.GetScalar(); | |
561 | Double_t db0=q.GetResultError(); | |
562 | Ali3Vector b=q.Get3Vector(); | |
d88f97cc | 563 | |
959fbac5 | 564 | Double_t c0=a0-b0; |
565 | Ali3Vector c=a-b; | |
566 | Double_t dc0=sqrt(pow(da0,2)+pow(db0,2)); | |
d88f97cc | 567 | |
568 | Ali4Vector v; | |
959fbac5 | 569 | v.SetVector(c0,c); |
570 | v.SetScalarError(dc0); | |
d88f97cc | 571 | return v; |
572 | } | |
573 | /////////////////////////////////////////////////////////////////////////// | |
574 | Ali4Vector Ali4Vector::operator*(Double_t s) | |
575 | { | |
959fbac5 | 576 | // Multiply the current 4-vector with a scalar s |
577 | // Error propagation is performed automatically | |
578 | Double_t a0=GetScalar(); | |
579 | Double_t da0=GetResultError(); | |
580 | Ali3Vector a=Get3Vector(); | |
d88f97cc | 581 | |
959fbac5 | 582 | a0*=s; |
583 | a*=s; | |
584 | da0*=s; | |
d88f97cc | 585 | |
586 | Ali4Vector v; | |
959fbac5 | 587 | v.SetVector(a0,a); |
588 | v.SetScalarError(da0); | |
d88f97cc | 589 | |
590 | return v; | |
591 | } | |
592 | /////////////////////////////////////////////////////////////////////////// | |
593 | Ali4Vector Ali4Vector::operator/(Double_t s) | |
594 | { | |
595 | // Divide the current vector by a scalar s | |
959fbac5 | 596 | // Error propagation is performed automatically |
d88f97cc | 597 | |
598 | if (fabs(s)<1.e-20) // Protect against division by 0 | |
599 | { | |
600 | cout << " *Ali4Vector::/* Division by 0 detected. No action taken." << endl; | |
601 | return *this; | |
602 | } | |
603 | else | |
604 | { | |
959fbac5 | 605 | Double_t a0=GetScalar(); |
606 | Double_t da0=GetResultError(); | |
607 | Ali3Vector a=Get3Vector(); | |
d88f97cc | 608 | |
959fbac5 | 609 | a0/=s; |
610 | a/=s; | |
611 | da0/=s; | |
d88f97cc | 612 | |
613 | Ali4Vector v; | |
959fbac5 | 614 | v.SetVector(a0,a); |
615 | v.SetScalarError(da0); | |
d88f97cc | 616 | |
617 | return v; | |
618 | } | |
619 | } | |
620 | /////////////////////////////////////////////////////////////////////////// | |
621 | Ali4Vector& Ali4Vector::operator+=(Ali4Vector& q) | |
622 | { | |
959fbac5 | 623 | // Add 4-vector q to the current 4-vector |
624 | // Error propagation is performed automatically | |
625 | Double_t a0=GetScalar(); | |
626 | Double_t da0=GetResultError(); | |
627 | Ali3Vector a=Get3Vector(); | |
628 | Double_t b0=q.GetScalar(); | |
629 | Double_t db0=q.GetResultError(); | |
630 | Ali3Vector b=q.Get3Vector(); | |
d88f97cc | 631 | |
959fbac5 | 632 | Double_t c0=a0+b0; |
633 | Ali3Vector c=a+b; | |
634 | Double_t dc0=sqrt(pow(da0,2)+pow(db0,2)); | |
d88f97cc | 635 | |
959fbac5 | 636 | SetVector(c0,c); |
637 | SetScalarError(dc0); | |
d88f97cc | 638 | |
639 | return *this; | |
640 | } | |
641 | /////////////////////////////////////////////////////////////////////////// | |
642 | Ali4Vector& Ali4Vector::operator-=(Ali4Vector& q) | |
643 | { | |
959fbac5 | 644 | // Subtract 4-vector q from the current 4-vector |
645 | // Error propagation is performed automatically | |
646 | Double_t a0=GetScalar(); | |
647 | Double_t da0=GetResultError(); | |
648 | Ali3Vector a=Get3Vector(); | |
649 | Double_t b0=q.GetScalar(); | |
650 | Double_t db0=q.GetResultError(); | |
651 | Ali3Vector b=q.Get3Vector(); | |
d88f97cc | 652 | |
959fbac5 | 653 | Double_t c0=a0-b0; |
654 | Ali3Vector c=a-b; | |
655 | Double_t dc0=sqrt(pow(da0,2)+pow(db0,2)); | |
d88f97cc | 656 | |
959fbac5 | 657 | SetVector(c0,c); |
658 | SetScalarError(dc0); | |
d88f97cc | 659 | |
d88f97cc | 660 | return *this; |
661 | } | |
662 | /////////////////////////////////////////////////////////////////////////// | |
663 | Ali4Vector& Ali4Vector::operator*=(Double_t s) | |
664 | { | |
959fbac5 | 665 | // Multiply the current 4-vector with a scalar s |
666 | // Error propagation is performed automatically | |
667 | Double_t a0=GetScalar(); | |
668 | Double_t da0=GetResultError(); | |
669 | Ali3Vector a=Get3Vector(); | |
d88f97cc | 670 | |
959fbac5 | 671 | a0*=s; |
672 | a*=s; | |
673 | da0*=s; | |
d88f97cc | 674 | |
959fbac5 | 675 | SetVector(a0,a); |
676 | SetScalarError(da0); | |
d88f97cc | 677 | |
d88f97cc | 678 | return *this; |
679 | } | |
680 | /////////////////////////////////////////////////////////////////////////// | |
681 | Ali4Vector& Ali4Vector::operator/=(Double_t s) | |
682 | { | |
683 | // Divide the current vector by a scalar s | |
959fbac5 | 684 | // Error propagation is performed automatically |
d88f97cc | 685 | |
686 | if (fabs(s)<1.e-20) // Protect against division by 0 | |
687 | { | |
959fbac5 | 688 | cout << " *Ali4Vector::/* Division by 0 detected. No action taken." << endl; |
d88f97cc | 689 | return *this; |
690 | } | |
691 | else | |
692 | { | |
959fbac5 | 693 | Double_t a0=GetScalar(); |
694 | Double_t da0=GetResultError(); | |
695 | Ali3Vector a=Get3Vector(); | |
d88f97cc | 696 | |
959fbac5 | 697 | a0/=s; |
698 | a/=s; | |
699 | da0/=s; | |
d88f97cc | 700 | |
959fbac5 | 701 | SetVector(a0,a); |
702 | SetScalarError(da0); | |
d88f97cc | 703 | |
704 | return *this; | |
705 | } | |
706 | } | |
707 | /////////////////////////////////////////////////////////////////////////// | |
959fbac5 | 708 | Int_t Ali4Vector::GetScalarFlag() |
709 | { | |
710 | // Provide the value of the fScalar flag (for internal use only). | |
711 | return fScalar; | |
712 | } | |
713 | /////////////////////////////////////////////////////////////////////////// | |
d071d629 | 714 | Ali3Vector Ali4Vector::GetVecTrans() |
715 | { | |
716 | // Provide the transverse vector part w.r.t. z-axis. | |
717 | // Error propagation is performed automatically | |
718 | ||
719 | return fV.GetVecTrans(); | |
720 | } | |
721 | /////////////////////////////////////////////////////////////////////////// | |
722 | Ali3Vector Ali4Vector::GetVecLong() | |
723 | { | |
724 | // Provide the longitudinal vector part w.r.t. z-axis. | |
725 | // Error propagation is performed automatically | |
726 | ||
727 | return fV.GetVecLong(); | |
728 | } | |
729 | /////////////////////////////////////////////////////////////////////////// | |
730 | Double_t Ali4Vector::GetScaTrans() | |
731 | { | |
732 | // Provide the "transverse value" of the scalar part w.r.t. z-axis. | |
733 | // This provides a basis for e.g. E_trans calculation. | |
734 | // Note : the returned value is always positive or zero. | |
735 | // The error on the value is available via GetResultError() | |
736 | // after invokation of GetScaTrans(). | |
737 | Double_t a[3],ea[3]; | |
738 | ||
739 | fV.GetVector(a,"sph"); | |
740 | fV.GetErrors(ea,"sph"); | |
741 | ||
742 | Double_t s=GetScalar(); | |
743 | Double_t ds=GetResultError(); | |
744 | ||
745 | Double_t st,dst2; | |
746 | st=s*sin(a[1]); | |
747 | dst2=pow((sin(a[1])*ds),2)+pow((s*cos(a[1])*ea[1]),2); | |
748 | ||
749 | fDresult=sqrt(dst2); | |
750 | return fabs(st); | |
751 | } | |
752 | /////////////////////////////////////////////////////////////////////////// | |
753 | Double_t Ali4Vector::GetScaLong() | |
754 | { | |
755 | // Provide the "longitudinal value" of the scalar part w.r.t. z-axis. | |
756 | // This provides a basis for e.g. E_long calculation. | |
757 | // Note : the returned value can also be negative. | |
758 | // The error on the value is available via GetResultError() | |
759 | // after invokation of GetScaLong(). | |
760 | Double_t a[3],ea[3]; | |
761 | ||
762 | fV.GetVector(a,"sph"); | |
763 | fV.GetErrors(ea,"sph"); | |
764 | ||
765 | Double_t s=GetScalar(); | |
766 | Double_t ds=GetResultError(); | |
767 | ||
768 | Double_t sl,dsl2; | |
769 | sl=s*cos(a[1]); | |
770 | dsl2=pow((cos(a[1])*ds),2)+pow((s*sin(a[1])*ea[1]),2); | |
771 | ||
772 | fDresult=sqrt(dsl2); | |
773 | return sl; | |
774 | } | |
775 | /////////////////////////////////////////////////////////////////////////// | |
776 | Double_t Ali4Vector::GetPseudoRapidity() | |
777 | { | |
778 | // Provide the pseudorapidity value of the vector part w.r.t. z-axis. | |
779 | // The error on the value is available via GetResultError() | |
780 | // after invokation of GetPseudoRapidity(). | |
781 | Double_t eta=fV.GetPseudoRapidity(); | |
782 | fDresult=fV.GetResultError(); | |
783 | return eta; | |
784 | } | |
785 | /////////////////////////////////////////////////////////////////////////// |