JRootToolkit.hh

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#ifndef __JROOTTOOLKIT__
#define __JROOTTOOLKIT__

#include <limits>

#include "TFile.h"
#include "TStreamerInfo.h"
#include "TList.h"
#include "TIterator.h"
#include "TString.h"
#include "TF1.h"

#include "JROOT/JRootFile.hh"


/**
 * \author mdejong
 */

namespace JROOT {}
namespace JPP { using namespace JROOT; }

namespace JROOT {


  /**
   * Write object to ROOT file.
   *
   * \param  file         ROOT file
   * \param  object       ROOT object
   * \return              ROOT file
   */
  TFile& operator<<(TFile& file, const TObject& object)
  {
    file.WriteTObject(&object);

    return file;
  }
  

  /**
   * Get ROOT streamer information of class with given name.
   * Note that the class name should include the name space, if any.
   *
   * \param  file         pointer to ROOT file
   * \param  name         class name
   * \return              pointer to TStreamerInfo (NULL in case of error)
   */
  inline const TStreamerInfo* getStreamerInfo(TFile* file, const char* name) 
  {
    if (file != NULL && file->IsOpen()) {

      const TString buffer(name);
        
      TIter iter(file->GetStreamerInfoList());

      for (const TStreamerInfo* pStreamerInfo; (pStreamerInfo = (TStreamerInfo*) iter.Next()) != NULL; ) {
        if (buffer == TString(pStreamerInfo->GetName())) {
          return pStreamerInfo;
        }
      }
    }

    return NULL;
  }


  /**
   * Get ROOT streamer information of class with given name.
   * Note that the class name should include the name space, if any.
   *
   * \param  file_name    file name
   * \param  name         class name
   * \return              pointer to TStreamerInfo (NULL in case of error)
   */
  inline const TStreamerInfo* getStreamerInfo(const char* file_name, const char* name) 
  {
    JRootInputFile file(file_name);

    return getStreamerInfo(file.getFile(), name);
  }


  /**
   * Get ROOT streamer version of class with given name.
   * Note that the class name should include the name space, if any.
   *
   * \param  file         pointer to ROOT file
   * \param  name         class name
   * \return              streamer version; (-1 in case of error)
   */
  inline int getStreamerVersion(TFile* file, const char* name) 
  {
    const TStreamerInfo* pStreamerInfo = getStreamerInfo(file, name);
    
    if (pStreamerInfo != NULL)
      return pStreamerInfo->GetClassVersion();
    else
      return -1;
  }


  /**
   * Get ROOT streamer version of class with given name.
   * Note that the class name should include the name space, if any.
   *
   * \param  file_name    file name
   * \param  name         class name
   * \return              streamer version; (-1 in case of error)
   */
  inline int getStreamerVersion(const char* file_name, const char* name) 
  {
    JRootInputFile file(file_name);
    
    return getStreamerVersion(file.getFile(), name);
  }

 
  /**
   * Auxiliary data structure for a parameter index and its value.
   */
  struct JFitParameter_t {
    /**
     * Default constructor.
     */
    JFitParameter_t() :
      index(0),
      value(0.0)
    {}


    /**
     * Constructor.
     *
     * \param  index        parameter index
     * \param  value        parameter value
     */
    JFitParameter_t(const Int_t    index,
                    const Double_t value) :
      index(index),
      value(value)
    {}


    /**
     * Type conversion operator
     *
     *
     * \return              index
     */
    inline operator Int_t() const
    { 
      return index;
    }

     
    Int_t    index;
    Double_t value;
  };
  

  /**
   * Set fit parameter.
   *
   * \param  f1           fit function
   * \param  parameter    parameter index and value
   */
  inline bool setParameter(TF1& f1, const JFitParameter_t& parameter)
  {
    if (parameter.index >= 0 && parameter.index < f1.GetNpar()) {

      f1.SetParameter(parameter.index, parameter.value);

      return true;

    } else {

      return false;
    }
  }


  /**
   * Fix fit parameter.
   *
   * \param  f1           fit function
   * \param  parameter    parameter index and value
   */
  inline bool fixParameter(TF1& f1, const JFitParameter_t& parameter)
  {
    if (parameter.index >= 0 && parameter.index < f1.GetNpar()) {

      f1.FixParameter(parameter.index, parameter.value);

      return true;

    } else {

      return false;
    }
  }


  /**
   * Release fit parameter.
   *
   * \param  f1           fit function
   * \param  index        parameter index
   */
  inline bool releaseParameter(TF1& f1, const Int_t index)
  {
    if (index >= 0 && index < f1.GetNpar()) {

      f1.ReleaseParameter(index);

      return true;

    } else {

      return false;
    }
  }


  /**
   * Set fit parameter limits.
   *
   * \param  f1           fit function
   * \param  index        parameter index
   * \param  xmin         lower limit
   * \param  xmax         upper limit
   */
  inline bool setParLimits(TF1& f1, const Int_t index, Double_t xmin, Double_t xmax)
  {
    using namespace std;

    if (index >= 0 && index < f1.GetNpar()) {

      if (xmin == 0.0) { xmin = -numeric_limits<Double_t>::min(); }
      if (xmax == 0.0) { xmax = +numeric_limits<Double_t>::min(); }

      f1.SetParLimits(index, xmin, xmax);

      return true;

    } else {

      return false;
    }
  }


  /**
   * Check if fit parameter is fixed.
   *
   * \param  f1           fit function
   * \param  index        parameter index
   */
  inline bool isParameterFixed(TF1& f1, const Int_t index)
  {
    if (index >= 0 && index < f1.GetNpar()) {

      Double_t xmin;
      Double_t xmax;
    
      f1.GetParLimits(index, xmin, xmax);
    
      return (xmin != 0.0 && xmax != 0.0 && xmin >= xmax);

    } else {
      
      return false;
    }
  }
}  

#endif