//-----------------------------------------------------// // // // // // Date : August 05 2003 // // // // Utility code for ALICE-PMD // // // //-----------------------------------------------------// #include "AliPMDUtility.h" #include "TMath.h" #include ClassImp(AliPMDUtility) AliPMDUtility::AliPMDUtility() { fPx = 0.; fPy = 0.; fPz = 0.; fTheta = 0.; fEta = 0.; fPhi = 0.; } AliPMDUtility::AliPMDUtility(Float_t Px, Float_t Py, Float_t Pz) { fPx = Px; fPy = Py; fPz = Pz; fTheta = 0.; fEta = 0.; fPhi = 0.; } AliPMDUtility::~AliPMDUtility() { } void AliPMDUtility::HexGeomCellPos(Int_t ism, Int_t xpad, Int_t ypad, Float_t &xpos, Float_t &ypos) { Int_t j = xpad; Int_t k = ypad; // Supermodeule number starting from 0 /* This converts PMD cluster or CELL coordinates to Global coordinates. Written by Prof. S.C. Phatak */ Int_t i; Float_t celldia = 0.5; const Float_t pi = 3.14159; const double sqrth=0.8660254; // sqrth = sqrt(3.)/2. /* ism --> supermodule no ( 0 - 26 ) idet --> detector ( pmd or cpv : not required now ) j --> xpad ( goes from 1 to 72 ) k --> ypad ( goes from 1 to 72 ) xp --> global x coordinate yp --> global y coordinate (xp0,yp0) corner positions of all supermodules in global coordinate system. That is the origin of the local ( supermodule ) coordinate system. */ Float_t xp0[27] = { -17.9084, 18.2166, 54.3416, -35.9709, 0.154144, 36.2791, -54.0334, -17.9084, 18.2166, 36.7791, 18.7166, 0.654194, 72.9041, 54.8416, 36.7792, 109.029, 90.9666, 72.9042, -18.8708, -36.9334, -54.996, -36.9332, -54.9958, -73.0584, -54.9956, -73.0582, -91.1208 }; Float_t yp0[27] = { -32.1395, -32.1395, -32.1395, -63.4247, -63.4247, -63.4247, -94.7098, -94.7098, -94.7098, 0.545689, 31.8309, 63.1161, 0.545632, 31.8308, 63.116, 0.545573, 31.8308, 63.116, 31.5737, 0.288616, -30.9965, 62.859, 31.5738, 0.288733, 94.1442, 62.8591, 31.574 }; /* angles of rotation for three sets of supermodules The angle is same for first nine, next nine and last nine supermodules */ Float_t th[3] = {0., -2.*pi/3., 2.*pi/3.}; Float_t xr, yr, xinit, yinit, cs, sn; /* xinit and yinit are coordinates of the cell in local coordinate system */ xinit = (j)*celldia+(k)/2.*celldia; yinit = sqrth*(k)/2.; i=ism/9; cs=cos(th[i]); sn=sin(th[i]); // // rotate first // xr=cs*xinit+sn*yinit; yr=-sn*xinit+cs*yinit; // // then translate // xpos=xr+xp0[ism]; ypos=yr+yp0[ism]; } void AliPMDUtility::RectGeomCellPos(Int_t ism, Int_t ium, Int_t xpad, Int_t ypad, Float_t &xpos, Float_t &ypos) { // This routine finds the cell eta,phi for the new PMD rectangular // geometry in ALICE // Authors : Bedanga Mohanty and Dipak Mishra - 29.4.2003 // modified by B. K. Nnadi for change of coordinate sys // // SMA ---> Supermodule Type A ( SM - 0) // SMAR ---> Supermodule Type A ROTATED ( SM - 1) // SMB ---> Supermodule Type B ( SM - 2) // SMBR ---> Supermodule Type B ROTATED ( SM - 3) // // ism : number of supermodules in one plane = 4 // ium : number of unitmodules in one SM = 6 // gb_um : (global) unit module numbering in a supermodule // Int_t gb_um = ism*6 + ium; Int_t irow = xpad; Int_t icol = ypad; // Corner positions (x,y) of the 24 unit moudles in ALICE PMD double xcorner[24] = { 85.15, 60.85, 36.55, 85.15, 60.85, 36.55, //SMA -85.15, -60.85, -36.55, -85.15, -60.85, -36.55, //SMAR 84.90, 36.60, 84.90, 36.60, 84.90, 36.60, //SMB -84.90, -36.60, -84.90, -36.60, -84.90, -36.60 //SMBR }; double ycorner[24] = { 32.45708755, 32.45708755, 32.45708755, //SMA -9.30645245, -9.30645245, -9.30645245, //SMA -32.45708755, -32.45708755, -32.45708755, //SMAR 9.30645245, 9.30645245, 9.30645245, //SMAR -31.63540818, -31.63540818, -52.61435544, //SMB -52.61435544, -73.59330270, -73.59330270, //SMB 31.63540818, 31.63540818, 52.61435544, //SMBR 52.61435544, 73.59330270, 73.59330270 //SMBR }; const Float_t root_3 = 1.73205; // sqrt(3.); const Float_t cell_radius = 0.25; // //Every even row of cells is shifted and placed //in geant so this condition // Float_t shift; if(irow%2 == 0) { shift = 0.25; } else { shift = 0.0; } if(ism == 0 || ism == 2) { ypos = ycorner[gb_um] + irow*cell_radius*root_3; xpos = xcorner[gb_um] - icol*2.0*cell_radius - shift; } else if(ism == 1 || ism == 3) { ypos = ycorner[gb_um] - irow*cell_radius*root_3; xpos = xcorner[gb_um] + icol*2.0*cell_radius + shift; } } void AliPMDUtility::SetPxPyPz(Float_t Px, Float_t Py, Float_t Pz) { fPx = Px; fPy = Py; fPz = Pz; } void AliPMDUtility::SetXYZ(Float_t xPos, Float_t yPos, Float_t zPos) { fPx = xPos; fPy = yPos; fPz = zPos; } void AliPMDUtility::CalculateEta() { Float_t rpxpy, theta, eta; rpxpy = TMath::Sqrt(fPx*fPx + fPy*fPy); theta = TMath::ATan2(rpxpy,fPz); eta = -TMath::Log(TMath::Tan(0.5*theta)); fTheta = theta; fEta = eta; } void AliPMDUtility::CalculatePhi() { Float_t pybypx, phi = 0., phi1; if(fPx==0) { if(fPy>0) phi = 90.; if(fPy<0) phi = 270.; } if(fPx != 0) { pybypx = fPy/fPx; if(pybypx < 0) pybypx = - pybypx; phi1 = TMath::ATan(pybypx)*180./3.14159; if(fPx > 0 && fPy > 0) phi = phi1; // 1st Quadrant if(fPx < 0 && fPy > 0) phi = 180 - phi1; // 2nd Quadrant if(fPx < 0 && fPy < 0) phi = 180 + phi1; // 3rd Quadrant if(fPx > 0 && fPy < 0) phi = 360 - phi1; // 4th Quadrant } phi = phi*3.14159/180.; fPhi = phi; } void AliPMDUtility::CalculateEtaPhi() { Float_t rpxpy, theta, eta; Float_t pybypx, phi = 0., phi1; rpxpy = TMath::Sqrt(fPx*fPx + fPy*fPy); theta = TMath::ATan2(rpxpy,fPz); eta = -TMath::Log(TMath::Tan(0.5*theta)); if(fPx==0) { if(fPy>0) phi = 90.; if(fPy<0) phi = 270.; } if(fPx != 0) { pybypx = fPy/fPx; if(pybypx < 0) pybypx = - pybypx; phi1 = TMath::ATan(pybypx)*180./3.14159; if(fPx > 0 && fPy > 0) phi = phi1; // 1st Quadrant if(fPx < 0 && fPy > 0) phi = 180 - phi1; // 2nd Quadrant if(fPx < 0 && fPy < 0) phi = 180 + phi1; // 3rd Quadrant if(fPx > 0 && fPy < 0) phi = 360 - phi1; // 4th Quadrant } phi = phi*3.14159/180.; fTheta = theta; fEta = eta; fPhi = phi; } Float_t AliPMDUtility::GetTheta() const { return fTheta; } Float_t AliPMDUtility::GetEta() const { return fEta; } Float_t AliPMDUtility::GetPhi() const { return fPhi; }