#include<iostream>
#include<cmath>
#include<fstream>
#include<string>
#include<TCanvas.h>
#include <TFile.h>
#include<TApplication.h>
#include<TGraphErrors.h>
#include<TH1D.h>
#include<TF1.h>
#include<TStyle.h>
#include<TAxis.h>
#include<TLatex.h>
#include<TMath.h>
#include<TTree.h>
#include<cstdlib>
#include<stdlib.h>
#include<TRandom.h>
#include "TH2F.h"
#include "TCanvas.h"
#include "TPad.h"
#include<cstring>
#include<sstream>  
#include<iomanip>
#include "TAxis.h"
#include "TH1.h"
#include "TArrayD.h"

using namespace std;


Double_t ScaleX(Double_t x, double c0, double c1, double c2)
{
  double v;
  
  v = c0 + c1*x + c2*x*x;
  
  return v;
}

double invoke(Double_t x, double c0, double c1, double c2, double (*func)(Double_t, double, double, double))
{
   return func(x, c0, c1, c2);
}


void ScaleAxis(TAxis *a, double, double, double, Double_t (*Scale)(Double_t))
{
  if (!a) return; 
  if (a->GetXbins()->GetSize())
    {
      TArrayD X(*(a->GetXbins()));
      for(Int_t i = 0; i < X.GetSize(); i++) X[i] = Scale(X[i]);
      a->Set((X.GetSize() - 1), X.GetArray()); 
    }
  else
    {
      a->Set( a->GetNbins(),
              Scale(a->GetXmin()), 
              Scale(a->GetXmax())); 
    }
  return;
} 

void ScaleXaxis(TH1 *h, double c0, double c1, double c2, Double_t (*Scale)(Double_t))
{
  if (!h) return; 
  ScaleAxis(h->GetXaxis(), c0,c1,c2, Scale);
  return;
}

void scaleaxis() {
	Double_t x;
	double c0 = 0;
   double c1 = 10;
   double c2 = 0;
	TFile *RootIn = TFile::Open("filein.hist","READ");
	TFile *RootOut = new TFile("fileout.hist","RECREATE");
	TH1F *h = (TH1F*)RootIn->Get("zint");
	invoke(x, c0, c1, c2, &ScaleX);
	ScaleXaxis(h, c0, c1, c2, ScaleX);
	h->ResetStats();
	h->Draw();
	h->Write();
	RootOut->Write();
	RootIn->Close();
	RootOut->Close();	
}