/* ======================================================================== *\ ! ! * ! * This file is part of MARS, the MAGIC Analysis and Reconstruction ! * Software. It is distributed to you in the hope that it can be a useful ! * and timesaving tool in analysing Data of imaging Cerenkov telescopes. ! * It is distributed WITHOUT ANY WARRANTY. ! * ! * Permission to use, copy, modify and distribute this software and its ! * documentation for any purpose is hereby granted without fee, ! * provided that the above copyright notice appear in all copies and ! * that both that copyright notice and this permission notice appear ! * in supporting documentation. It is provided "as is" without express ! * or implied warranty. ! * ! ! ! Author(s): Thomas Bretz 12/2000 ! Author(s): Harald Kornmayer 1/2001 ! Author(s): Rudolf Bock 10/2001 ! Author(s): Wolfgang Wittek 6/2002 ! ! Copyright: MAGIC Software Development, 2000-2003 ! ! \* ======================================================================== */ ///////////////////////////////////////////////////////////////////////////// // // MHillas // // Storage Container for image parameters // // basic image parameters // // Version 1: // ---------- // fLength [mm] major axis of ellipse // fWidth [mm] minor axis // fDelta [rad] angle of major axis with x-axis // by definition the major axis is pointing into // the hemisphere x>0, thus -pi/2 < delta < pi/2 // fSize [#CerPhot] total sum of pixels // fMeanX [mm] x of center of ellipse // fMeanY [mm] y of center of ellipse // // Version 2: // ---------- // fNumCorePixels number of pixels called core // fNumUsedPixels number of pixels which survived the cleaning // // Version 3: // ---------- // fNumCorePixels moved to MNewImagePar // fNumUsedPixels moved to MNewImagePar // fCosDelta added // fSinDelte added // ///////////////////////////////////////////////////////////////////////////// #include "MHillas.h" #include #include #include #include #include "MGeomPix.h" #include "MGeomCam.h" #include "MCerPhotPix.h" #include "MCerPhotEvt.h" #include "MLog.h" #include "MLogManip.h" ClassImp(MHillas); using namespace std; // -------------------------------------------------------------------------- // // Default constructor. // MHillas::MHillas(const char *name, const char *title) { fName = name ? name : "MHillas"; fTitle = title ? title : "Storage container for image parameters of one event"; Reset(); } // -------------------------------------------------------------------------- // // Initializes the values with defaults. For the default values see the // source code. // void MHillas::Reset() { fLength = -1; fWidth = -1; fDelta = 0; fSize = -1; fMeanX = 0; fMeanY = 0; } // -------------------------------------------------------------------------- // // return the mean position as TVector2(meanx, meany) // TVector2 MHillas::GetMean() const { return TVector2(fMeanX, fMeanY); } // -------------------------------------------------------------------------- // // Print the hillas Parameters to *fLog // void MHillas::Print(Option_t *) const { Double_t atg = atan2(fMeanY, fMeanX)*kRad2Deg; if (atg<0) atg += 180; *fLog << all; *fLog << "Basic Image Parameters (" << GetName() << ")" << endl; *fLog << " - Length [mm] = " << fLength << endl; *fLog << " - Width [mm] = " << fWidth << endl; *fLog << " - Delta [deg] = " << fDelta*kRad2Deg << endl; *fLog << " - Size [1] = " << fSize << " #CherPhot" << endl; *fLog << " - Meanx [mm] = " << fMeanX << endl; *fLog << " - Meany [mm] = " << fMeanY << endl; *fLog << " - atg(y/x) [deg] = " << atg << endl; } // -------------------------------------------------------------------------- // // Print the hillas Parameters to *fLog, depending on the geometry in // units of deg // void MHillas::Print(const MGeomCam &geom) const { Double_t atg = atan2(fMeanY, fMeanX)*kRad2Deg; if (atg<0) atg += 180; *fLog << all; *fLog << "Basic Image Parameters (" << GetName() << ")" << endl; *fLog << " - Length [deg] = " << fLength*geom.GetConvMm2Deg() << endl; *fLog << " - Width [deg] = " << fWidth *geom.GetConvMm2Deg() << endl; *fLog << " - Delta [deg] = " << fDelta*kRad2Deg << endl; *fLog << " - Size [1] = " << fSize << " #CherPhot" << endl; *fLog << " - Meanx [deg] = " << fMeanX *geom.GetConvMm2Deg() << endl; *fLog << " - Meany [deg] = " << fMeanY *geom.GetConvMm2Deg() << endl; *fLog << " - atg(y/x) [deg] = " << atg << endl; } // -------------------------------------------------------------------------- // // Paint the ellipse corresponding to the parameters // void MHillas::Paint(Option_t *opt) { static const Float_t sOffsetW=40.0; static const Float_t sOffsetL=266.0; if (fLength<0 || fWidth<0) return; const Float_t l = fLength+sOffsetL; const Float_t w = fWidth +sOffsetW; TLine line; line.SetLineWidth(1); line.SetLineColor(kRed); line.Paint(); // Length line line.PaintLine(-l*fCosDelta+fMeanX, -l*fSinDelta+fMeanY, +l*fCosDelta+fMeanX, +l*fSinDelta+fMeanY); // Width line line.PaintLine(+w*fSinDelta+fMeanX, -w*fCosDelta+fMeanY, -w*fSinDelta+fMeanX, +w*fCosDelta+fMeanY); TEllipse e(fMeanX, fMeanY, fLength, fWidth, 0, 360, fDelta*kRad2Deg+180); e.SetLineWidth(2); e.SetLineColor(kGreen); e.Paint(); } // -------------------------------------------------------------------------- // // Calculate the image parameters from a Cherenkov photon event // assuming Cher.photons/pixel and pixel coordinates are given // In case you don't call Calc from within an eventloop make sure, that // you call the Reset member function before. // Returns: // 0 no error // 1 number of pixels < 3 // 2 size==0 // 3 number of used pixel < 3 // 4 CorrXY == 0 // Int_t MHillas::Calc(const MGeomCam &geom, const MCerPhotEvt &evt, Int_t island) { // // sanity check 1 // if (evt.GetNumPixels()<3) return 1; // // calculate mean value of pixel coordinates and fSize // ----------------------------------------------------- // // Because this are only simple sums of roughly 600 values // with an accuracy less than three digits there should not // be any need to use double precision (Double_t) for the // calculation of fMeanX, fMeanY and fSize. // fMeanX = 0; fMeanY = 0; fSize = 0; MCerPhotPix *pix = 0; TIter Next(evt); UInt_t numused = 0; while ((pix=(MCerPhotPix*)Next())) { if (island>=0 && pix->GetIdxIsland()!=island) continue; const MGeomPix &gpix = geom[pix->GetPixId()]; const Float_t nphot = pix->GetNumPhotons(); fSize += nphot; // [counter] fMeanX += nphot * gpix.GetX(); // [mm] fMeanY += nphot * gpix.GetY(); // [mm] numused++; } // // sanity check 2 // if (fSize==0) return 2; fMeanX /= fSize; // [mm] fMeanY /= fSize; // [mm] // // sanity check 3 // if (numused<3) return 3; // // calculate 2nd moments // --------------------- // // To make sure that the more complicated sum is evaluated as // accurate as possible (because it is needed for more // complicated calculations (see below) we calculate it using // double prcision. // Double_t corrxx=0; // [m^2] Double_t corrxy=0; // [m^2] Double_t corryy=0; // [m^2] Next.Reset(); while ((pix=(MCerPhotPix*)Next())) { if (island>=0 && pix->GetIdxIsland()!=island) continue; const MGeomPix &gpix = geom[pix->GetPixId()]; const Float_t dx = gpix.GetX() - fMeanX; // [mm] const Float_t dy = gpix.GetY() - fMeanY; // [mm] const Float_t nphot = pix->GetNumPhotons(); // [#phot] corrxx += nphot * dx*dx; // [mm^2] corrxy += nphot * dx*dy; // [mm^2] corryy += nphot * dy*dy; // [mm^2] } // // If corrxy=0 (which should happen not very often, because fSize>0) // we cannot calculate Length and Width. // In reallity it is almost impossible to have a distribution of // cerenkov photons in the used pixels which is exactly symmetric // along one of the axis. // It seems to be less than 0.1% of all events. // if (corrxy==0) return 4; // // calculate the basic Hillas parameters: orientation and size of axes // ------------------------------------------------------------------- // // fDelta is the angle between the major axis of the ellipse and // the x axis. It is independent of the position of the ellipse // in the camera it has values between -pi/2 and pi/2 degrees // // Rem: I tested replacing sqrt() by hypot() but they exactly // consume the same amount of time // const Double_t d0 = corryy - corrxx; const Double_t d1 = corrxy*2; const Double_t d2 = d0 + TMath::Sqrt(d0*d0 + d1*d1); const Double_t tand = d2 / d1; const Double_t tand2 = tand*tand; fDelta = TMath::ATan(tand); const Double_t s2 = tand2+1; const Double_t s = TMath::Sqrt(s2); fCosDelta = 1.0/s; // need these in derived classes fSinDelta = tand/s; // like MHillasExt const Double_t axis1 = (tand2*corryy + d2 + corrxx)/s2/fSize; const Double_t axis2 = (tand2*corrxx - d2 + corryy)/s2/fSize; // // fLength^2 is the second moment along the major axis of the ellipse // fWidth^2 is the second moment along the minor axis of the ellipse // // From the algorithm we get: fWidth <= fLength is always true // // very small numbers can get negative by rounding // fLength = axis1<0 ? 0 : TMath::Sqrt(axis1); // [mm] fWidth = axis2<0 ? 0 : TMath::Sqrt(axis2); // [mm] SetReadyToSave(); return 0; } // -------------------------------------------------------------------------- // // This function is ment for special usage, please never try to set // values via this function // void MHillas::Set(const TArrayF &arr) { if (arr.GetSize() != 6) return; fLength = arr.At(0); // [mm] major axis of ellipse fWidth = arr.At(1); // [mm] minor axis of ellipse fDelta = arr.At(2); // [rad] angle of major axis with x-axis fSize = arr.At(3); // [#CerPhot] sum of content of all pixels (number of Cherenkov photons) fMeanX = arr.At(4); // [mm] x-coordinate of center of ellipse fMeanY = arr.At(5); // [mm] y-coordinate of center of ellipse }