Dead region: |000/
|00/
|0/
- // expects x, z in microns
+ // expects x, z in cm
*/
/*
Float_t P=0;
Float_t N=0;
if(fLayer==5) {
- P = 105.26*x - 0.79*z + 381.89;
- N = P + 3.68*z - 4;
+ P = 105.26*x - 0.7895*z + 382.000; //- 0.79*z + 381.89;
+ N = P + 3.684*z - 4;
}
else if(fLayer==6) {
- P = -105.26*x - 0.79*z + 384.66;
- N = P + 3.68*z + 4;
+ P = -105.26*x - 0.7895*z + 385.000; //- 0.79*z + 384.66;
+ N = P + 3.684*z + 4;
}
else AliError("Layer can be 5 or 6");
//----------------------------------------------------------------------
void AliITSsegmentationSSD::GetPadIxz(Float_t x,Float_t z,Int_t &iP,Int_t &iN) const {
// returns P and N sided strip numbers for a given location.
- /* _- Z
- + angle / ^
- fNstrips v | N-Side ...0
- \-------/------------|-----------\--------\
- |\\\\\\/////////////.|\\\\\\\\\\\\\\\\\\\\|
- |0\\\\/////////////..|.\\\\\\\\\\\\\\\\\\\|
- |00\\/////////////...|..\\\\\\\\\\\\\\\\\\|
- X <--|000/////////////... |...\\\\\\\\\\\\\\\\\|
- |00/////////////... | ...\\\\\\\\\\\\\\\\|
- |0/////////////... | ...\\\\\\\\\\\\\\\|
- |//////////////... | ...\\\\\\\\\\\\\\\|
- /-----\--------------|--------------------/
- fNstrips-1 P-Side ...0
- |0\
- |00\
- Dead region: |000/
- |00/
- |0/
-
- // expects x, z in microns
- */
-
- Float_t stereoP, stereoN;
- Angles(stereoP,stereoN);
- Float_t tanP=TMath::Tan(stereoP);
- Float_t tanN=TMath::Tan(stereoN);
- Float_t x1=x,z1=z;
- x1 += fDx/2;
- z1 += fDz/2;
- Float_t ldX = x1 - z1*tanP; // distance from left-down edge
- iP = (Int_t)(ldX/fPitch);
- iP = (iP<0)? -1: iP;
- iP = (iP>fNstrips)? -1: iP;
-
- ldX = x1 - tanN*(fDz - z1);
- iN = (Int_t)(ldX/fPitch);
- iN = (iN<0)? -1: iN;
- iN = (iN>fNstrips)? -1: iN;
+ // expects x, z in cm
+ GetPadTxz(x,z);
+ iP = Int_t(x+0.5);
+ iN = Int_t(z+0.5);
}
//-------------------------------------------------------
-void AliITSsegmentationSSD::GetPadCxz(Int_t iP,Int_t iN,Float_t &x,Float_t &z) const {
+void AliITSsegmentationSSD::GetPadCxz(Float_t iP,Float_t iN,Float_t &x,Float_t &z) const {
// actually this is the GetCrossing(Float_t &,Float_t &)
- // returns local x, z in microns !
+ // returns local x, z in cm
+ const Float_t kStartXzero=3.64325;
+ const Float_t kDeltaXzero5or6=0.02239;
+ const Float_t kDeltaZ5to6=7.6/7.0;
- Float_t lDx = fDx; // detector size in x direction, microns
- Float_t lDz = fDz; // detector size in z direction, microns
- Float_t xP; // x coordinate in the P side from the first P strip
- Float_t xN; // x coordinate in the N side from the first N strip
- Float_t stereoP, stereoN;
- Angles(stereoP,stereoN);
- Float_t kP=TMath::Tan(stereoP);
- Float_t kN=TMath::Tan(stereoN);
-
- xP=iP*fPitch;
- xN=iN*fPitch;
- x = xP + kP*(lDz*kN-xP+xN)/(kP+kN);
- z = (lDz*kN-xP+xN)/(kP+kN);
- x -= lDx/2;
- z -= lDz/2;
- //if(TMath::Abs(z) > Dz/2) cout<<"Warning, wrong z local ="<<z<<endl;
- // Check that zL is inside the detector for the
- // correspondent xP and xN coordinates
+ z = 1.9*(iN-iP)/7.0;
+ x = kStartXzero-(285*iN + 1045*iP)/140000.0;
- return;
+ if (fLayer==5){
+ z += kDeltaZ5to6;
+ x = -x + kDeltaXzero5or6;
+ }
+ else if (fLayer==6) {
+ z -= kDeltaZ5to6;
+ x += kDeltaXzero5or6;
+ }
+ else {
+ AliWarning("Layer shoudl be 5 or 6");
+ x = -99999;
+ z = -99999;
+ }
}
//______________________________________________________________________
Bool_t AliITSsegmentationSSD::LocalToDet(Float_t x,Float_t z,
// x = a + b + z*tan(fStereoP); a = Dpx(iP)*(iP+0.5)-dx; b = dz*th;
// for strips n-side
// x = a + b + z*tan(fStereoP); a = Dpx(iN)*(iN+0.5)-dx; b = -dz*th;
+ AliWarning("This function has not been verified. Should probably use GetPadCxz");
const Double_t kconst = 1.0E-04; // convert microns to cm.
Float_t flag=kconst*Dx(); // error value
Double_t th=0.0,dx,dz,i,a,b=0.0,xb[4],zb[4];
z *= 0.5;
return;
}
-//----------------------------------------------------------------------
-Bool_t AliITSsegmentationSSD::GetCrossing(Int_t iP,Int_t iN,
- Float_t &x,Float_t &z,
- Float_t c[2][2]){
- // Given one P side strip and one N side strip, Returns kTRUE if they
- // cross each other and the location of the two crossing strips and
- // their correxlation matrix c[2][2].
- /* _- Z
- + angle / ^
- fNstrips v | N-Side ...0
- \-------/------------|-----------\--------\
- |\\\\\\/////////////.|\\\\\\\\\\\\\\\\\\\\|
- |0\\\\/////////////..|.\\\\\\\\\\\\\\\\\\\|
- |00\\/////////////...|..\\\\\\\\\\\\\\\\\\|
- X <--|000/////////////... |...\\\\\\\\\\\\\\\\\|
- |00/////////////... | ...\\\\\\\\\\\\\\\\|
- |0/////////////... | ...\\\\\\\\\\\\\\\|
- |//////////////... | ...\\\\\\\\\\\\\\\|
- /-----\--------------|--------------------/
- fNstrips-1 P-Side ...0
- |0\
- |00\
- Dead region: |000/
- |00/
- |0/
- c[2][2] is defined as follows
- /c[0][0] c[0][1]\ /delta iP\ = /delta x\
- \c[1][0] c[1][1]/ \delta iN/ = \delta z/
- */
- const Double_t kconst = 1.0E-04; // convert microns to cm.
- Double_t thp,thn,th,dx,dz,p,ip,in;
- Float_t stereoP, stereoN;
- Angles(stereoP,stereoN);
-
- thp = TMath::Tan(stereoP);
- thn = TMath::Tan(-stereoN);
- th = thp-thn;
- if(th==0.0) { // parall strips then never cross.
- x = 0.0;
- z = 0.0;
- c[0][0] = c[1][0] = c[0][1] = c[1][1] = 0.0;
- return kFALSE;
- } // end if
- // The strips must cross some place in space.
- ip = (Double_t) iP; // convert to double now for speed
- in = (Double_t) iN; // convert to double now for speed
- dx = 0.5*kconst*Dx(); // half distance in x in cm
- dz = 0.5*kconst*Dz(); // half distance in z in cm
- p = kconst*Dpx(iP); // Get strip spacing/pitch now
- x = 0.5*p+dx + (p*(in*thp-ip*thn)-2.0*dz*thp*thn)/th;
- z =(p*(in-ip)-dz*(thp+thn))/th;
- // compute correlations.
- c[0][0] = -thn*p/th; // dx/diP
- c[1][1] = p/th; // dz/diN
- c[0][1] = p*thp/th; // dx/diN
- c[1][0] = -p/th; // dz/diP
- if(x<-dx || x>dx || z<-dz || z>dz) return kFALSE; // crossing is outside
- // of the detector so
- // these strips don't
- // cross.
- return kTRUE;
-}
-
//----------------------------------------------------------------------
Int_t AliITSsegmentationSSD::GetChipFromChannel(Int_t ix, Int_t iz) const {
// returns chip number (in range 0-11) starting from channel number
Int_t AliITSsegmentationSSD::GetChipsInLocalWindow(Int_t* array, Float_t zmin, Float_t zmax,
Float_t xmin, Float_t xmax) const {
+ // returns chip number in a given xz window
Int_t nChipInW = 0;