/**************************************************************************
 * Copyright(c) 1998-2007, ALICE Experiment at CERN, All rights reserved. *
 *                                                                        *
 * Author: The ALICE Off-line Project.                                    *
 * Contributors are mentioned in the code where appropriate.              *
 *                                                                        *
 * Permission to use, copy, modify and distribute this software and its   *
 * documentation strictly for non-commercial purposes is hereby granted   *
 * without fee, provided that the above copyright notice appears in all   *
 * copies and that both the copyright notice and this permission notice   *
 * appear in the supporting documentation. The authors make no claims     *
 * about the suitability of this software for any purpose. It is          *
 * provided "as is" without express or implied warranty.                  *
 **************************************************************************/

/*
 * Container class for histogram objects. Currenly can handle
 *   TH1
 *   TH2
 *   TH3
 *   THnSparse
 * Histograms can be stored in groups. For this the parent group is 
 * included inside the histogram name, i.e. /base/inheriting/histogram.
 * In case just the histogram name is given, it is assumed that the
 * histogram is stored at the top level.
 *
 *   Author: Markus Fasel
 */

#include <cstring>
#include <vector>
#include <TArrayD.h>
#include <TAxis.h>
#include <TH1.h>
#include <TH2.h>
#include <TH3.h>
#include <THnSparse.h>
#include <THashList.h>
#include <TObjArray.h>
#include <TObjString.h>
#include <TString.h>

#include "AliLog.h"

#include "AliEMCalHistoContainer.h"

ClassImp(EMCalTriggerPtAnalysis::AliEMCalHistoContainer)

namespace EMCalTriggerPtAnalysis {

	//______________________________________________________________________________
	AliEMCalHistoContainer::AliEMCalHistoContainer():
                		TNamed(),
                		fHistos(NULL),
                		fIsOwner(true)
	{
		/*
		 * Default constructor, only initialising pointers with 0
		 */
	}

	//______________________________________________________________________________
	AliEMCalHistoContainer::AliEMCalHistoContainer(const char *name):
                		TNamed(name, Form("Histogram container %s", name)),
                		fHistos(NULL),
                		fIsOwner(true)
	{
		/*
		 * Main constructor, creating also a list for the histograms
		 *
		 * @param name: Name of the object (list named accordingly)
		 */
		fHistos = new THashList();
		fHistos->SetName(Form("histos%s", name));
		fHistos->SetOwner();
	}

	//______________________________________________________________________________
	AliEMCalHistoContainer::~AliEMCalHistoContainer(){
		/*
		 * Destructor, deletes the list of histograms if it is the owner
		 */
		if(fHistos && fIsOwner) delete fHistos;
	}

	//______________________________________________________________________________
	void AliEMCalHistoContainer::CreateHistoGroup(const char *groupname, const char *parent) throw(HistoContainerContentException) {
		/*
		 * Create a new group of histograms within a parent group. Groups are represented as list. The default parent is
		 * always the top list. List name structure accouding to unix paths (i.e. top list /, hirarchies separated by /).
		 *
		 * @param groupname: Name of the new group
		 * @param parent (@default "/"): Name of the parent group
		 * @throw HistoContainerContentException
		 */
		THashList *parentgroup = FindGroup(parent);
		if(!parentgroup) throw HistoContainerContentException(NULL, parent, HistoContainerContentException::kGroupException);
		THashList *childgroup = new THashList();
		childgroup->SetName(groupname);
		parentgroup->Add(childgroup);
	}

	//______________________________________________________________________________
	void AliEMCalHistoContainer::CreateTH1(const char *name, const char *title, int nbins, double xmin, double xmax) throw(HistoContainerContentException){
		/*
		 * Create a new TH1 within the container. The histogram name also contains the parent group(s) according to the common
		 * group notation.
		 *
		 * @param name: Name of the histogram
		 * @param title: Title of the histogram
		 * @param nbins: number of bins
		 * @param xmin: min. value of the range
		 * @param xmax: max. value of the range
		 * @throw HistoContainerContentException
		 */
		TString dirname(basename(name)), hname(histname(name));
		THashList *parent(FindGroup(dirname.Data()));
		if(!parent)
			throw HistoContainerContentException(NULL, dirname.Data(), HistoContainerContentException::kGroupException);
		if(parent->FindObject(hname.Data()))
			throw HistoContainerContentException(hname.Data(), dirname.Data(), HistoContainerContentException::kHistDuplicationException);
		parent->Add(new TH1D(hname.Data(), title, nbins, xmin, xmax));
	}

	//______________________________________________________________________________
	void AliEMCalHistoContainer::CreateTH1(const char *name, const char *title, int nbins, const double *xbins) throw(HistoContainerContentException){
		/*
		 * Create a new TH1 within the container. The histogram name also contains the parent group(s) according to the common
		 * group notation.
		 *
		 * @param name: Name of the histogram
		 * @param title: Title of the histogram
		 * @param nbins: number of bins
		 * @param xbins: array of bin limits
		 * @throw HistoContainerContentException
		 */
		TString dirname(basename(name)), hname(histname(name));
		THashList *parent(FindGroup(dirname));
		if(!parent)
			throw HistoContainerContentException(NULL, dirname.Data(), HistoContainerContentException::kGroupException);
		if(parent->FindObject(hname.Data()))
			throw HistoContainerContentException(hname, dirname.Data(), HistoContainerContentException::kHistDuplicationException);
		parent->Add(new TH1D(hname.Data(), title, nbins, xbins));
	}

	//______________________________________________________________________________
	void AliEMCalHistoContainer::CreateTH1(const char *name, const char *title, const TArrayD &xbins) throw(HistoContainerContentException){
		/*
		 * Create a new TH1 within the container. The histogram name also contains the parent group(s) according to the common
		 * group notation.
		 *
		 * @param name: Name of the histogram
		 * @param title: Title of the histogram
		 * @param xbins: array of bin limits (contains also number of bins)
		 * @throw HistoContainerContentException
		 */
		TString dirname(basename(name)), hname(histname(name));
		THashList *parent(FindGroup(dirname));
		if(!parent)
			throw HistoContainerContentException(NULL, dirname.Data(), HistoContainerContentException::kGroupException);
		if(parent->FindObject(hname.Data()))
			throw HistoContainerContentException(hname.Data(), dirname.Data(), HistoContainerContentException::kHistDuplicationException);
		parent->Add(new TH1D(hname.Data(), title, xbins.GetSize()-1, xbins.GetArray()));
	}

	//______________________________________________________________________________
	void AliEMCalHistoContainer::CreateTH2(const char *name, const char *title,
			int nbinsx, double xmin, double xmax, int nbinsy, double ymin, double ymax) throw(HistoContainerContentException){
		/*
		 * Create a new TH2 within the container. The histogram name also contains the parent group(s) according to the common
		 * group notation.
		 *
		 * @param name: Name of the histogram
		 * @param title: Title of the histogram
		 * @param nbinsx: number of bins in x-direction
		 * @param xmin: min. value of the range in x-direction
		 * @param xmax: max. value of the range in x-direction
		 * @param nbinsy: number of bins in y-direction
		 * @param ymin: min. value of the range in y-direction
		 * @param ymax: max. value of the range in y-direction
		 * @throw HistoContainerContentException
		 */
		TString dirname(basename(name)), hname(histname(name));
		THashList *parent(FindGroup(dirname.Data()));
		if(!parent)
			throw HistoContainerContentException(NULL, dirname.Data(), HistoContainerContentException::kGroupException);
		if(parent->FindObject(hname.Data()))
			throw HistoContainerContentException(hname.Data(), dirname.Data(), HistoContainerContentException::kHistDuplicationException);
		parent->Add(new TH2D(hname.Data(), title, nbinsx, xmin, xmax, nbinsy, ymin, ymax));
	}

	//______________________________________________________________________________
	void AliEMCalHistoContainer::CreateTH2(const char *name, const char *title,
			int nbinsx, const double *xbins, int nbinsy, const double *ybins) throw(HistoContainerContentException){
		/*
		 * Create a new TH2 within the container. The histogram name also contains the parent group(s) according to the common
		 * group notation.
		 *
		 * @param name: Name of the histogram
		 * @param title: Title of the histogram
		 * @param nbinsx: number of bins in x-direction
		 * @param xbins: array of bin limits in x-direction
		 * @param nbinsy: number of bins in y-direction
		 * @param ybins: array of bin limits in y-direction
		 * @throw HistoContainerContentException
		 */
		TString dirname(basename(name)), hname(histname(name));
		THashList *parent(FindGroup(dirname.Data()));
		if(!parent)
			throw HistoContainerContentException(NULL, dirname.Data(), HistoContainerContentException::kGroupException);
		if(parent->FindObject(hname.Data()))
			throw HistoContainerContentException(hname.Data(), dirname.Data(), HistoContainerContentException::kHistDuplicationException);
		parent->Add(new TH2D(hname.Data(), title, nbinsx, xbins, nbinsy, ybins));
	}

	//______________________________________________________________________________
	void AliEMCalHistoContainer::CreateTH2(const char *name, const char *title, const TArrayD &xbins, const TArrayD &ybins) throw(HistoContainerContentException){
		/*
		 * Create a new TH2 within the container. The histogram name also contains the parent group(s) according to the common
		 * group notation.
		 *
		 * @param name: Name of the histogram
		 * @param title: Title of the histogram
		 * @param xbins: array of bin limits in x-direction (contains also the number of bins)
		 * @param ybins: array of bin limits in y-direction (contains also the number of bins)
		 * @throw HistoContainerContentException
		 */
		TString dirname(basename(name)), hname(histname(name));
		THashList *parent(FindGroup(dirname.Data()));
		if(!parent)
			throw HistoContainerContentException(NULL, dirname.Data(), HistoContainerContentException::kGroupException);
		if(parent->FindObject(hname.Data()))
			throw HistoContainerContentException(hname.Data(), dirname.Data(), HistoContainerContentException::kHistDuplicationException);
		parent->Add(new TH2D(hname.Data(), title, xbins.GetSize() - 1, xbins.GetArray(), ybins.GetSize() - 1, ybins.GetArray()));
	}

	//______________________________________________________________________________
	void AliEMCalHistoContainer::CreateTH3(const char* name, const char* title, int nbinsx, double xmin, double xmax,
			int nbinsy, double ymin, double ymax, int nbinsz, double zmin, double zmax) throw (HistoContainerContentException) {
		/*
		 * Create a new TH3 within the container. The histogram name also contains the parent group(s) according to the common
		 * group notation.
		 *
		 * @param nbinsx: number of bins in x-direction
		 * @param xmin: min. value of the range in x-direction
		 * @param xmax: max. value of the range in x-direction
		 * @param nbinsy: number of bins in y-direction
		 * @param ymin: min. value of the range in y-direction
		 * @param ymax: max. value of the range in y-direction
		 * @param nbinsz: number of bins in z-direction
		 * @param zmin: min. value of the range in z-direction
		 * @param zmax: max. value of the range in z-direction
		 * @throw HistoContainerContentException
		 */
		TString dirname(basename(name)), hname(histname(name));
		THashList *parent(FindGroup(dirname.Data()));
		if(!parent)
			throw HistoContainerContentException(NULL, dirname.Data(), HistoContainerContentException::kGroupException);
		if(parent->FindObject(hname.Data()))
			throw HistoContainerContentException(hname.Data(), dirname.Data(), HistoContainerContentException::kHistDuplicationException);
		parent->Add(new TH3D(hname.Data(), title, nbinsx, xmin, xmax, nbinsy, ymin, ymax, nbinsz, zmin, zmax));
	}

	//______________________________________________________________________________
	void AliEMCalHistoContainer::CreateTH3(const char* name, const char* title, int nbinsx, const double* xbins,
			int nbinsy, const double* ybins, int nbinsz, const double* zbins) throw (HistoContainerContentException) {
		/*
		 * Create a new TH3 within the container. The histogram name also contains the parent group(s) according to the common
		 * group notation.
		 *
		 * @param name: Name of the histogram
		 * @param title: Title of the histogram
		 * @param nbinsx: number of bins in x-direction
		 * @param xbins: array of bin limits in x-direction
		 * @param nbinsy: number of bins in y-direction
		 * @param ybins: array of bin limits in y-direction
		 * @param nbinsz: number of bins in z-direction
		 * @param zbins: array of bin limits in z-direction
		 * @throw HistoContainerContentException
		 */
		TString dirname(basename(name)), hname(histname(name));
		THashList *parent(FindGroup(dirname.Data()));
		if(!parent)
			throw HistoContainerContentException(NULL, dirname.Data(), HistoContainerContentException::kGroupException);
		if(parent->FindObject(hname.Data()))
			throw HistoContainerContentException(hname.Data(), dirname.Data(), HistoContainerContentException::kHistDuplicationException);
		parent->Add(new TH3D(hname.Data(), title, nbinsx, xbins, nbinsy, ybins, nbinsz, zbins));
	}

	//______________________________________________________________________________
	void AliEMCalHistoContainer::CreateTH3(const char* name, const char* title, const TArrayD& xbins, const TArrayD& ybins,
			const TArrayD& zbins) throw (HistoContainerContentException) {
		/*
		 * Create a new TH3 within the container. The histogram name also contains the parent group(s) according to the common
		 * group notation.
		 *
		 * @param name: Name of the histogram
		 * @param title: Title of the histogram
		 * @param xbins: array of bin limits in x-direction (contains also the number of bins)
		 * @param ybins: array of bin limits in y-direction (contains also the number of bins)
		 * @param zbins: array of bin limits in z-direction (contains also the number of bins)
		 * @throw HistoContainerContentException
		 */
		TString dirname(basename(name)), hname(histname(name));
		THashList *parent(FindGroup(dirname.Data()));
		if(!parent)
			throw HistoContainerContentException(NULL, dirname.Data(), HistoContainerContentException::kGroupException);
		if(parent->FindObject(hname.Data()))
			throw HistoContainerContentException(hname.Data(), dirname.Data(), HistoContainerContentException::kHistDuplicationException);
		parent->Add(new TH3D(hname.Data(), title, xbins.GetSize()-1, xbins.GetArray(), ybins.GetSize()-1, ybins.GetArray(), zbins.GetSize()-1, zbins.GetArray()));
	}

	//______________________________________________________________________________
	void AliEMCalHistoContainer::CreateTHnSparse(const char *name, const char *title,
			int ndim, const int *nbins, const double *min, const double *max) throw(HistoContainerContentException){
		/*
		 * Create a new THnSparse within the container. The histogram name also contains the parent group(s) according to the common
		 * group notation.
		 *
		 * @param name: Name of the histogram
		 * @param title: Title of the histogram
		 * @param ndim: Number of dimensions
		 * @param nbins: Number of bins per dimension
		 * @param min: min. value of the range for each dimension
		 * @param max: max. value of the range for each dimension
		 * @throw HistoContainerContentException
		 */
		TString dirname(basename(name)), hname(histname(name));
		THashList *parent(FindGroup(dirname.Data()));
		if(!parent)
			throw HistoContainerContentException(NULL, dirname.Data(), HistoContainerContentException::kGroupException);
		if(parent->FindObject(hname.Data()))
			throw HistoContainerContentException(hname.Data(), dirname.Data(), HistoContainerContentException::kHistDuplicationException);
		parent->Add(new THnSparseD(hname.Data(), title, ndim, nbins, min, max));
	}

	//______________________________________________________________________________
	void AliEMCalHistoContainer::CreateTHnSparse(const char *name, const char *title, int ndim, const TAxis **axes) throw(HistoContainerContentException){
		/*
		 * Create a new THnSparse within the container. The histogram name also contains the parent group(s) according to the common
		 * group notation.
		 *
		 * @param name: Name of the histogram
		 * @param title: Title of the histogram
		 * @param ndim: Number of dimensions
		 * @param axes: Array of pointers to TAxis for containing the axis definition for each dimension
		 * @throw HistoContainerContentException
		 */
		TString dirname(basename(name)), hname(histname(name));
		THashList *parent(FindGroup(dirname.Data()));
		if(!parent)
			throw HistoContainerContentException(NULL, dirname.Data(), HistoContainerContentException::kGroupException);
		if(parent->FindObject(hname))
			throw HistoContainerContentException(hname.Data(), dirname.Data(), HistoContainerContentException::kHistDuplicationException);
		TArrayD xmin(ndim), xmax(ndim);
		TArrayI nbins(ndim);
		for(int idim = 0; idim < ndim; ++idim){
			const TAxis &myaxis = *(axes[idim]);
			nbins[idim] = myaxis.GetNbins();
			xmin[idim] = myaxis.GetXmin();
			xmax[idim] = myaxis.GetXmax();
		}
		THnSparseD *hsparse = new THnSparseD(hname.Data(), title, ndim, nbins.GetArray(), xmin.GetArray(), xmax.GetArray());
		for(int id = 0; id < ndim; ++id)
			*(hsparse->GetAxis(id)) = *(axes[id]);
		parent->Add(hsparse);
	}

	//______________________________________________________________________________
	void AliEMCalHistoContainer::SetObject(TObject * const o, const char *group) throw(HistoContainerContentException){
		/*
		 * Set a new group into the container into the parent group
		 *
		 * @param o: the object ot be included

		 */
		THashList *parent(FindGroup(group));
		if(!parent)
			throw HistoContainerContentException(NULL, strcmp(group, "/") ? group : "", HistoContainerContentException::kGroupException);
		if(parent->FindObject(o->GetName()))
			throw HistoContainerContentException(o->GetName(), strcmp(group, "/") ? group : "", HistoContainerContentException::kHistDuplicationException);
		if(!(dynamic_cast<THnBase *>(o) || dynamic_cast<TH1 *>(o)))
			throw HistoContainerContentException(o->GetName(), strcmp(group, "/") ? group : "", HistoContainerContentException::kTypeException);
		fHistos->Add(o);
	}

	//______________________________________________________________________________
	void AliEMCalHistoContainer::FillTH1(const char *name, double x, double weight) throw(HistoContainerContentException){
		/*
		 * Fill a 1D histogram within the container. The histogram name also contains the parent group(s) according to the common
		 * group notation.
		 *
		 * @param name: Name of the histogram
		 * @param x: x-coordinate
		 * @param weight (@default 1): optional weight of the entry
		 * @throw HistoContainerContentException
		 */
		TString dirname(basename(name)), hname(histname(name));
		THashList *parent(FindGroup(dirname.Data()));
		if(!parent)
			throw HistoContainerContentException(NULL, dirname.Data(), HistoContainerContentException::kGroupException);
		TH1 *hist = dynamic_cast<TH1 *>(parent->FindObject(hname.Data()));
		if(!hist)
			throw HistoContainerContentException(hname.Data(), dirname.Data(), HistoContainerContentException::kHistNotFoundException);
		hist->Fill(x, weight);
	}

	//______________________________________________________________________________
	void AliEMCalHistoContainer::FillTH2(const char *name, double x, double y, double weight) throw(HistoContainerContentException){
		/*
		 * Fill a 2D histogram within the container. The histogram name also contains the parent group(s) according to the common
		 * group notation.
		 *
		 * @param name: Name of the histogram
		 * @param x: x-coordinate
		 * @param y: y-coordinate
		 * @param weight (@default 1): optional weight of the entry
		 * @throw HistoContainerContentException
		 */
		TString dirname(basename(name)), hname(histname(name));
		THashList *parent(FindGroup(dirname.Data()));
		if(!parent)
			throw HistoContainerContentException(NULL, dirname.Data(), HistoContainerContentException::kGroupException);
		TH2 *hist = dynamic_cast<TH2 *>(parent->FindObject(hname.Data()));
		if(!hist)
			throw HistoContainerContentException(hname.Data(), dirname.Data(), HistoContainerContentException::kHistNotFoundException);
		hist->Fill(x, y, weight);
	}

	//______________________________________________________________________________
	void AliEMCalHistoContainer::FillTH2(const char *name, double *point, double weight) throw(HistoContainerContentException){
		/*
		 * Fill a 2D histogram within the container. The histogram name also contains the parent group(s) according to the common
		 * group notation.
		 *
		 * @param name: Name of the histogram
		 * @param point: coordinates of the data
		 * @param weight (@default 1): optional weight of the entry
		 * @throw HistoContainerContentException
		 */
		TString dirname(basename(name)), hname(histname(name));
		THashList *parent(FindGroup(dirname.Data()));
		if(!parent)
			throw HistoContainerContentException(NULL, dirname.Data(), HistoContainerContentException::kGroupException);
		TH2 *hist = dynamic_cast<TH2 *>(parent->FindObject(hname.Data()));
		if(!hist)
			throw HistoContainerContentException(hname.Data(), dirname.Data(), HistoContainerContentException::kHistNotFoundException);
		hist->Fill(point[0], point[1], weight);
	}

	//______________________________________________________________________________
	void AliEMCalHistoContainer::FillTH3(const char* name, double x, double y, double z, double weight) throw (HistoContainerContentException) {
		/*
		 * Fill a 3D histogram within the container. The histogram name also contains the parent group(s) according to the common
		 * group notation.
		 *
		 * @param name: Name of the histogram
		 * @param x: x-coordinate
		 * @param y: y-coordinate
		 * @param z: z-coordinate
		 * @param weight (@default 1): optional weight of the entry
		 * @throw HistoContainerContentException
		 */
		TString dirname(basename(name)), hname(histname(name));
		THashList *parent(FindGroup(dirname.Data()));
		if(!parent)
			throw HistoContainerContentException(NULL, dirname.Data(), HistoContainerContentException::kGroupException);
		TH3 *hist = dynamic_cast<TH3 *>(parent->FindObject(hname.Data()));
		if(!hist)
			throw HistoContainerContentException(hname.Data(), dirname.Data(), HistoContainerContentException::kHistNotFoundException);
		hist->Fill(x, y, z, weight);
	}

	//______________________________________________________________________________
	void AliEMCalHistoContainer::FillTH3(const char* name, const double* point, double weight) throw (HistoContainerContentException) {
		TString dirname(basename(name)), hname(histname(name));
		THashList *parent(FindGroup(dirname.Data()));
		if(!parent)
			throw HistoContainerContentException(NULL, dirname.Data(), HistoContainerContentException::kGroupException);
		TH3 *hist = dynamic_cast<TH3 *>(parent->FindObject(hname.Data()));
		if(!hist)
			throw HistoContainerContentException(hname.Data(), dirname.Data(), HistoContainerContentException::kHistNotFoundException);
		hist->Fill(point[0], point[1], point[2], weight);
	}


	//______________________________________________________________________________
	void AliEMCalHistoContainer::FillTHnSparse(const char *name, const double *x, double weight) throw(HistoContainerContentException){
		/*
		 * Fill a  nD histogram within the container. The histogram name also contains the parent group(s) according to the common
		 * group notation.
		 *
		 * @param name: Name of the histogram
		 * @param x: coordinates of the data
		 * @param weight (@default 1): optional weight of the entry
		 * @throw HistoContainerContentException
		 */
		TString dirname(basename(name)), hname(histname(name));
		THashList *parent(FindGroup(dirname.Data()));
		if(!parent)
			throw HistoContainerContentException(NULL, dirname.Data(), HistoContainerContentException::kGroupException);
		THnSparseD *hist = dynamic_cast<THnSparseD *>(parent->FindObject(hname.Data()));
		if(!hist)
			throw HistoContainerContentException(hname.Data(), dirname.Data(), HistoContainerContentException::kHistNotFoundException);
		hist->Fill(x, weight);
	}

	//______________________________________________________________________________
	TObject *AliEMCalHistoContainer::FindObject(const char *name) const {
		/*
		 * Find an object inside the container. The object can also be within a
		 * histogram group. For this the name has to follow the common notation
		 *
		 * @param name: Name of the object to find inside the container
		 * @return: pointer to the object (NULL if not found)
		 */
		TString dirname(basename(name)), hname(histname(name));
		THashList *parent(FindGroup(dirname.Data()));
		if(!parent) return NULL;
		return parent->FindObject(name);
	}

	//______________________________________________________________________________
	THashList *AliEMCalHistoContainer::FindGroup(const char *dirname) const {
		/*
		 * Find histogram group. Name is using common notation
		 *
		 * @param dirname: Path of the group (treat empty path as top node
		 * @return: TList of objects (NULL if group does not exist)
		 */
		if(!strlen(dirname) || !strcmp(dirname, "/")) return fHistos;
		std::vector<std::string> tokens;
		TokenizeFilename(dirname, "/", tokens);
		THashList *currentdir(fHistos);
		for(std::vector<std::string>::iterator it = tokens.begin(); it != tokens.end(); ++it){
			currentdir = dynamic_cast<THashList *>(currentdir->FindObject(it->c_str()));
			if(!currentdir) break;
		}
		return currentdir;
	}

	//______________________________________________________________________________
	void AliEMCalHistoContainer::TokenizeFilename(const char *name, const char *delim, std::vector<std::string> &listoftokens) const {
		/*
		 * Tokenizes a string. Results are stored inside the vector listoftokens
		 *
		 * @ param name: string to be tokenised
		 * @ param delim: delimiter string
		 * @ param listoftokens: list of tokens (C++ strings)
		 */
		TString s(name);
		TObjArray *arr = s.Tokenize(delim);
		TObjString *ostr(NULL);
		TIter toks(arr);
		while((ostr = dynamic_cast<TObjString *>(toks()))){
			listoftokens.push_back(std::string(ostr->String().Data()));
		}
		delete arr;
	}

	//______________________________________________________________________________
	const char *AliEMCalHistoContainer::basename(const char *path) const {
		/*
		 * Helper function extracting the basename from a given histogram path.
		 *
		 * @param path: histogram path
		 * @return: basename extracted
		 */
		TString s(path);
		int index = s.Last('/');
		if(index < 0) return "";  // no directory structure
		return TString(s(0, index)).Data();
	}

	//______________________________________________________________________________
	const char *AliEMCalHistoContainer::histname(const char *path) const {
		/*
		 * Helper function extracting the histogram name from a given histogram path.
		 *
		 * @param path: histogram path
		 * @return: basename extracted
		 */
		TString s(path);
		int index = s.Last('/');
		if(index < 0) return path;    // no directory structure
		return TString(s(index+1, s.Length() - (index+1))).Data();
	}
}