// This task finds the eventplane
// using the FMD
// 
#ifndef ALIFMDEVENTPLANEFINDER_H 
#define ALIFMDEVENTPLANEFINDER_H 
/**
 * @file AliFMDEventPlaneFinder.h
 * @author Alexander Hansen
 * @date   Tue Feb 14 2012
 * 
 * @brief
 * 
 * 
 * @ingroup pwglf_forward
 */
#include <TNamed.h>
#include <TVector2.h>
#include "AliForwardUtil.h"
class AliVEvent;
class TH1D;
class TH2F;
class TH2D;
class TString;
class AliOADBContainer;
class AliAODForwardEP;

class AliFMDEventPlaneFinder : public TNamed
{
public:
  /** 
   * Constructor 
   */
  AliFMDEventPlaneFinder();
  /** 
   * Constructor 
   * 
   * @param name Name of object
   */
  AliFMDEventPlaneFinder(const char* name);
  /** 
   * Copy constructor 
   * 
   * @param o Object to copy from 
   */
  AliFMDEventPlaneFinder(const AliFMDEventPlaneFinder& o);
  /** 
   * Destructor 
   */
  virtual ~AliFMDEventPlaneFinder();
  /** 
   * Assignement operator
   * 
   * @param o Object to assign from 
   * 
   * @return Reference to this object
   */
  AliFMDEventPlaneFinder& operator=(const AliFMDEventPlaneFinder& o);
 /** 
   * Initialize this sub-algorithm
   * 
   */
  virtual void Init(const TAxis& etaAxis);
  /** 
   * Do the calculations 
   * 
   * @param hists    Histogram cache
   * 
   * @return true on successs 
   */
  Bool_t FindEventplane(AliVEvent* esd,
                        AliAODForwardEP& aodEp,
                        TH2D* h,
                        AliForwardUtil::Histos* hists);
  /** 
   * Output diagnostic histograms to directory 
   * 
   * @param dir List to write in
   */  
  virtual void DefineOutput(TList* dir);
  /** 
   * Print information 
   * 
   * @param option Print options 
   *   - max  Print max weights 
   */
  void Print(Option_t* option="") const;
 /** 
   * Set the debug level.  The higher the value the more output 
   * 
   * @param dbg Debug level 
   */
  void SetDebug(Int_t dbg=1) { fDebug = dbg; }
 /*
  * Calculate Q vectors
  *
  * @param h dN/detadphi histogram
  * @param eHist histogram for ep vs. eta
  */
  void CalcQVectors(TH2D* h, TH1D* eHist);
 /*
  * Calculate the eventplane from a vector
  *
  * @param v TVector2 of Q-vectors
  *
  * @return the eventplane as a double
  */
  Double_t CalcEventplane(TVector2 v) const;
 /*
  * Set the run number, used for OADB object
  *
  * @param run Run number
  */
  void SetRunNumber(Int_t run);
 /*
  * Get the run number
  *
  * @return returns the run number
  */
  Int_t GetRunNumber() { return fRunNumber; }
 /*
  * Get the OADB phi distribution for flattening
  */
  void GetPhiDist();
 /*
  * Flag for setting the use of phi weights for flattening
  * 
  * @param use true or false
  */
  void SetUsePhiWeights(Bool_t use = kTRUE) { fUsePhiWeights = use; }
 /*
  * Fill diagnostics hists
  *
  * @param fmdEP Object containing results of FMD EP calculations
  */
  void FillHists(AliAODForwardEP* fmdEP);
 /*
  * Set the OADB path, for using a custom OADB path and file
  *
  * @param fname Name of the custom OADB file, including path
  */
  void SetOADBPath(Char_t* fname) { fOADBFileName = fname; }

protected:
 /*
  * Get the phi weight from OADB histogram for the ep flattening
  *
  * @param etaBin which eta bin
  * @param phiBin which phi bin
  *
  * @return phi weight for etaBin, phiBin as double
  */
  Double_t GetPhiWeight(Int_t etaBin, Int_t phiBin) const;
 
  TList*            fList;              // List for diag. hists.
  AliVEvent*        fEvent;             // Current event
  TVector2          fQt;                // Q vector for total ep
  TVector2          fQa;                // Q vector for sub-ep A
  TVector2          fQc;                // Q vector for sub-ep C
  TVector2          fQ1;                // Q vector for sub-ep 1
  TVector2          fQ2;                // Q vector for sub-ep 2
  TVector2          fQeta;              // Q vector for psi eta-dependence
  TH1D*             fHistFMDEventplane; // Diagnostics histogram
  TH1D*             fHistFMDEventplaneA;// Diagnostics histogram
  TH1D*             fHistFMDEventplaneC;// Diagnostics histogram
  TH1D*             fHistFMDEventplane1;// Diagnostics histogram
  TH1D*             fHistFMDEventplane2;// Diagnostics histogram
  TH2D*             fHistPhiDist;       // Diagnostics histogram
  TH1D*             fHistFMDmTPCep;     // Diagnostics histogram
  TH2F*             fHistFMDvsTPCep;    // Diagnostics histogram
  TH1D*             fHistFMDmVZEROep;   // Diagnostics histogram
  TH2F*             fHistFMDvsVZEROep;  // Diagnostics histogram
  Int_t             fDebug;             // Debug flag
  TString           fOADBFileName;      // Path to OADB container
  AliOADBContainer* fOADBContainer;     // OADBContainer object
  TH2D*             fPhiDist;           // Phi dist. for phi weights
  Int_t             fRunNumber;         // Run number supplied
  Bool_t            fUsePhiWeights;     // Flag for phi weights

  ClassDef(AliFMDEventPlaneFinder,1); //  
};

#endif
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