]>
Commit | Line | Data |
---|---|---|
edc97986 | 1 | /************************************************************************** |
2 | * Copyright(c) 1998-2003, 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 | **************************************************************************/ | |
090026bf | 15 | |
16 | /* $Id$ */ | |
17 | ||
edc97986 | 18 | /////////////////////////////////////////////////////////////////// |
19 | // // | |
20 | // A straight line is coded as a point (3 Double_t) and // | |
21 | // 3 direction cosines // | |
22 | // // | |
23 | /////////////////////////////////////////////////////////////////// | |
090026bf | 24 | |
edc97986 | 25 | #include <Riostream.h> |
26 | #include <TTree.h> | |
090026bf | 27 | #include <TMath.h> |
28 | ||
edc97986 | 29 | #include "AliStrLine.h" |
30 | ||
31 | ClassImp(AliStrLine) | |
32 | ||
33 | //________________________________________________________ | |
fe12e09c | 34 | AliStrLine::AliStrLine() : |
35 | TObject(), | |
36 | fTpar(0), | |
37 | fDebug(0) | |
38 | { | |
edc97986 | 39 | // Default constructor |
40 | for(Int_t i=0;i<3;i++) { | |
41 | fP0[i] = 0.; | |
28dc94e2 | 42 | fSigma2P0[i] = 0.; |
edc97986 | 43 | fCd[i] = 0.; |
44 | } | |
edc97986 | 45 | } |
46 | ||
47 | //________________________________________________________ | |
fe12e09c | 48 | AliStrLine::AliStrLine(Double_t *point, Double_t *cd,Bool_t twopoints) : |
49 | TObject(), | |
50 | fTpar(0), | |
51 | fDebug(0) | |
52 | { | |
edc97986 | 53 | // Standard constructor |
24a0c65f | 54 | // if twopoints is true: point and cd are the 3D coordinates of |
55 | // two points defininig the straight line | |
56 | // if twopoint is false: point represents the 3D coordinates of a point | |
57 | // belonging to the straight line and cd is the | |
58 | // direction in space | |
28dc94e2 | 59 | for(Int_t i=0;i<3;i++) fSigma2P0[i] = 0.; |
24a0c65f | 60 | if(twopoints){ |
61 | InitTwoPoints(point,cd); | |
62 | } | |
63 | else { | |
64 | InitDirection(point,cd); | |
65 | } | |
66 | } | |
67 | ||
2c9641ee | 68 | //________________________________________________________ |
69 | AliStrLine::AliStrLine(Float_t *pointf, Float_t *cdf,Bool_t twopoints) : | |
70 | TObject(), | |
71 | fTpar(0), | |
72 | fDebug(0) | |
73 | { | |
74 | // Standard constructor - with float arguments | |
75 | // if twopoints is true: point and cd are the 3D coordinates of | |
76 | // two points defininig the straight line | |
77 | // if twopoint is false: point represents the 3D coordinates of a point | |
78 | // belonging to the straight line and cd is the | |
79 | // direction in space | |
80 | Double_t point[3]; | |
81 | Double_t cd[3]; | |
82 | for(Int_t i=0;i<3;i++){ | |
83 | point[i] = pointf[i]; | |
84 | cd[i] = cdf[i]; | |
28dc94e2 | 85 | fSigma2P0[i] = 0.; |
2c9641ee | 86 | } |
87 | if(twopoints){ | |
88 | InitTwoPoints(point,cd); | |
89 | } | |
90 | else { | |
91 | InitDirection(point,cd); | |
92 | } | |
93 | } | |
24a0c65f | 94 | |
28dc94e2 | 95 | //________________________________________________________ |
96 | AliStrLine::AliStrLine(Double_t *point, Double_t *sig2point, Double_t *cd,Bool_t twopoints) : | |
97 | TObject(), | |
98 | fTpar(0), | |
99 | fDebug(0) | |
100 | { | |
101 | // Standard constructor | |
102 | // if twopoints is true: point and cd are the 3D coordinates of | |
103 | // two points defininig the straight line | |
104 | // if twopoint is false: point represents the 3D coordinates of a point | |
105 | // belonging to the straight line and cd is the | |
106 | // direction in space | |
107 | for(Int_t i=0;i<3;i++) fSigma2P0[i] = sig2point[i]; | |
108 | if(twopoints){ | |
109 | InitTwoPoints(point,cd); | |
110 | } | |
111 | else { | |
112 | InitDirection(point,cd); | |
113 | } | |
114 | } | |
115 | ||
116 | //________________________________________________________ | |
117 | AliStrLine::AliStrLine(Float_t *pointf, Float_t *sig2point, Float_t *cdf,Bool_t twopoints) : | |
118 | TObject(), | |
119 | fTpar(0), | |
120 | fDebug(0) | |
121 | { | |
122 | // Standard constructor - with float arguments | |
123 | // if twopoints is true: point and cd are the 3D coordinates of | |
124 | // two points defininig the straight line | |
125 | // if twopoint is false: point represents the 3D coordinates of a point | |
126 | // belonging to the straight line and cd is the | |
127 | // direction in space | |
128 | Double_t point[3]; | |
129 | Double_t cd[3]; | |
130 | for(Int_t i=0;i<3;i++){ | |
131 | point[i] = pointf[i]; | |
132 | cd[i] = cdf[i]; | |
133 | fSigma2P0[i] = sig2point[i]; | |
134 | } | |
135 | if(twopoints){ | |
136 | InitTwoPoints(point,cd); | |
137 | } | |
138 | else { | |
139 | InitDirection(point,cd); | |
140 | } | |
141 | } | |
24a0c65f | 142 | //________________________________________________________ |
143 | void AliStrLine::InitDirection(Double_t *point, Double_t *cd){ | |
144 | // Initialization from a point and a direction | |
edc97986 | 145 | Double_t norm = 0.; |
146 | for(Int_t i=0;i<3;i++)norm+=cd[i]*cd[i]; | |
147 | if(norm) { | |
148 | norm = TMath::Sqrt(norm); | |
149 | for(Int_t i=0;i<3;i++) cd[i]/=norm; | |
150 | } | |
151 | else { | |
152 | Error("AliStrLine","Null direction cosines!!!"); | |
153 | } | |
154 | SetP0(point); | |
155 | SetCd(cd); | |
156 | fTpar = 0.; | |
157 | SetDebug(); | |
158 | } | |
159 | ||
24a0c65f | 160 | //________________________________________________________ |
161 | void AliStrLine::InitTwoPoints(Double_t *pA, Double_t *pB){ | |
162 | // Initialization from the coordinates of two | |
163 | // points in the space | |
164 | Double_t cd[3]; | |
165 | for(Int_t i=0;i<3;i++)cd[i] = pB[i]-pA[i]; | |
166 | InitDirection(pA,cd); | |
167 | } | |
168 | ||
edc97986 | 169 | //________________________________________________________ |
170 | AliStrLine::~AliStrLine() { | |
171 | // destructor | |
172 | } | |
173 | ||
174 | //________________________________________________________ | |
175 | void AliStrLine::PrintStatus() const { | |
176 | // Print current status | |
177 | cout <<"=======================================================\n"; | |
178 | cout <<"Direction cosines: "; | |
179 | for(Int_t i=0;i<3;i++)cout <<fCd[i]<<"; "; | |
180 | cout <<endl; | |
181 | cout <<"Known point: "; | |
182 | for(Int_t i=0;i<3;i++)cout <<fP0[i]<<"; "; | |
183 | cout <<endl; | |
28dc94e2 | 184 | cout <<"Error on known point: "; |
185 | for(Int_t i=0;i<3;i++)cout <<TMath::Sqrt(fSigma2P0[i])<<"; "; | |
186 | cout <<endl; | |
edc97986 | 187 | cout <<"Current value for the parameter: "<<fTpar<<endl; |
188 | cout <<" Debug flag: "<<fDebug<<endl; | |
189 | } | |
190 | ||
191 | //________________________________________________________ | |
192 | Int_t AliStrLine::IsParallelTo(AliStrLine *line) const { | |
193 | // returns 1 if lines are parallel, 0 if not paralel | |
194 | Double_t cd2[3]; | |
195 | line->GetCd(cd2); | |
196 | Double_t vecpx=fCd[1]*cd2[2]-fCd[2]*cd2[1]; | |
197 | if(vecpx!=0) return 0; | |
198 | Double_t vecpy=-fCd[0]*cd2[2]+fCd[2]*cd2[0]; | |
199 | if(vecpy!=0) return 0; | |
200 | Double_t vecpz=fCd[0]*cd2[1]-fCd[1]*cd2[0]; | |
201 | if(vecpz!=0) return 0; | |
202 | return 1; | |
203 | } | |
204 | //________________________________________________________ | |
205 | Int_t AliStrLine::Crossrphi(AliStrLine *line){ | |
206 | // Cross 2 lines in the X-Y plane | |
207 | Double_t p2[3]; | |
208 | Double_t cd2[3]; | |
209 | line->GetP0(p2); | |
210 | line->GetCd(cd2); | |
211 | Double_t a=fCd[0]; | |
212 | Double_t b=-cd2[0]; | |
213 | Double_t c=p2[0]-fP0[0]; | |
214 | Double_t d=fCd[1]; | |
215 | Double_t e=-cd2[1]; | |
216 | Double_t f=p2[1]-fP0[1]; | |
217 | Double_t deno = a*e-b*d; | |
218 | Int_t retcode = 0; | |
219 | if(deno != 0.) { | |
220 | fTpar = (c*e-b*f)/deno; | |
221 | } | |
222 | else { | |
223 | retcode = -1; | |
224 | } | |
225 | return retcode; | |
226 | } | |
227 | ||
228 | //________________________________________________________ | |
229 | Int_t AliStrLine::CrossPoints(AliStrLine *line, Double_t *point1, Double_t *point2){ | |
230 | // Looks for the crossing point estimated starting from the | |
231 | // DCA segment | |
232 | Double_t p2[3]; | |
233 | Double_t cd2[3]; | |
234 | line->GetP0(p2); | |
235 | line->GetCd(cd2); | |
236 | Int_t i; | |
237 | Double_t k1 = 0; | |
238 | for(i=0;i<3;i++)k1+=(fP0[i]-p2[i])*fCd[i]; | |
239 | Double_t k2 = 0; | |
240 | for(i=0;i<3;i++)k2+=(fP0[i]-p2[i])*cd2[i]; | |
241 | Double_t a11 = 0; | |
242 | for(i=0;i<3;i++)a11+=fCd[i]*cd2[i]; | |
243 | Double_t a22 = -a11; | |
244 | Double_t a21 = 0; | |
245 | for(i=0;i<3;i++)a21+=cd2[i]*cd2[i]; | |
246 | Double_t a12 = 0; | |
247 | for(i=0;i<3;i++)a12-=fCd[i]*fCd[i]; | |
248 | Double_t deno = a11*a22-a21*a12; | |
249 | if(deno == 0.) return -1; | |
250 | fTpar = (a11*k2-a21*k1) / deno; | |
251 | Double_t par2 = (k1*a22-k2*a12) / deno; | |
252 | line->SetPar(par2); | |
253 | GetCurrentPoint(point1); | |
254 | line->GetCurrentPoint(point2); | |
255 | return 0; | |
256 | } | |
257 | //________________________________________________________________ | |
258 | Int_t AliStrLine::Cross(AliStrLine *line, Double_t *point){ | |
259 | ||
260 | //Finds intersection between lines | |
261 | Double_t point1[3]; | |
262 | Double_t point2[3]; | |
263 | Int_t retcod=CrossPoints(line,point1,point2); | |
264 | if(retcod==0){ | |
265 | for(Int_t i=0;i<3;i++)point[i]=(point1[i]+point2[i])/2.; | |
266 | return 0; | |
267 | }else{ | |
268 | return -1; | |
269 | } | |
270 | } | |
271 | ||
272 | //___________________________________________________________ | |
2c9641ee | 273 | Double_t AliStrLine::GetDCA(AliStrLine *line) const{ |
edc97986 | 274 | //Returns the distance of closest approach between two lines |
275 | Double_t p2[3]; | |
276 | Double_t cd2[3]; | |
277 | line->GetP0(p2); | |
278 | line->GetCd(cd2); | |
279 | Int_t i; | |
280 | Int_t ispar=IsParallelTo(line); | |
281 | if(ispar){ | |
282 | Double_t dist1q=0,dist2=0,mod=0; | |
283 | for(i=0;i<3;i++){ | |
284 | dist1q+=(fP0[i]-p2[i])*(fP0[i]-p2[i]); | |
285 | dist2+=(fP0[i]-p2[i])*fCd[i]; | |
286 | mod+=fCd[i]*fCd[i]; | |
287 | } | |
288 | if(mod!=0){ | |
289 | dist2/=mod; | |
290 | return TMath::Sqrt(dist1q-dist2*dist2); | |
291 | }else{return -1;} | |
292 | }else{ | |
293 | Double_t perp[3]; | |
294 | perp[0]=fCd[1]*cd2[2]-fCd[2]*cd2[1]; | |
295 | perp[1]=-fCd[0]*cd2[2]+fCd[2]*cd2[0]; | |
296 | perp[2]=fCd[0]*cd2[1]-fCd[1]*cd2[0]; | |
297 | Double_t mod=0,dist=0; | |
298 | for(i=0;i<3;i++){ | |
299 | mod+=perp[i]*perp[i]; | |
300 | dist+=(fP0[i]-p2[i])*perp[i]; | |
301 | } | |
302 | mod=sqrt(mod); | |
303 | if(mod!=0){ | |
304 | dist/=mod; | |
305 | return TMath::Abs(dist); | |
306 | }else{return -1;} | |
307 | } | |
308 | } | |
309 | //________________________________________________________ | |
310 | void AliStrLine::GetCurrentPoint(Double_t *point) const { | |
311 | // Fills the array point with the current value on the line | |
312 | for(Int_t i=0;i<3;i++)point[i]=fP0[i]+fCd[i]*fTpar; | |
313 | } | |
2c9641ee | 314 | |
315 | //________________________________________________________ | |
316 | Double_t AliStrLine::GetDistFromPoint(Double_t *point) const { | |
317 | // computes distance from point | |
318 | AliStrLine tmp(point,(Double_t *)fCd,kFALSE); | |
319 | return this->GetDCA(&tmp); | |
320 | } |