/***************************************************************************
 * --------------------------------------------------------------------------
 * Template to exercise Random Numbers and CLT
 * -> Book and fill a histogram with 10000 uniform random numbers
 * --------------------------------------------------------------------------
 * 13.06.2005, Klaus Rabbertz
 *
 * modification log:
 * kr, 04.07.2006: Removed explicit ex10 naming
 * as, 06.06.2008: Some fixes for running as macro
 * gq, 22.12.2010: extracted from ranclt_2
 ***************************************************************************/

/* Note that this file can be either used as a compiled program
 * or as a ROOT macro.
 * If it is used as a compiled program, additional include statements
 * and the definition of the main program have to be made. This is 
 * not needed if the code is used as a macro.
 */
#ifndef __CINT__      // These include-statements are needed if the program is
                      // run as a "stand-alone application", i.e. if it is not 
                      // called from an interactive ROOT session
#include <iostream>

#include "TFile.h"    
#include "TH1.h"      
#include "TH2.h"
#include "TProfile.h"
#include "TRandom.h"
#include "TMath.h"
#include "TCanvas.h"
#include "TPad.h"
#include "TF1.h"
#include "TStyle.h"
#include "TText.h"

#include <math.h>

// Here we declare the functions we are going to use later.
// Each function corresponds to one subexercise
void ex11();
void rancor();
void erprop();
void ranexp();
//______________________________________________________________________________
int main()
{
  ex11();  
  return 0;
}
#endif                 

void ex11()
{
  // Here we call the functions solving the subexercises.
  // If you are just working on one, comment out the others.
   rancor();
   erprop();
   ranexp();
}
//______________________________________________________________________________

// from here on, the code can also be used as a macro

void rancor()
{
  // Create a new ROOT file.
  TFile hfile("rancor.root", "RECREATE", "rancor");

  // Book a 1D histogram "hran" (or any other name) holding 100 random numbers.

  // Create vector of pointers to 1D histograms. 
  // Each pointer points to a histogram which holds the content of a 
  // specific bin.
  TH1F *hlist[5]; 

  // Book 1D histograms for content of each bin of the above histogram
  hlist[0] = new TH1F("hran01","bin 1",50,0.0,50.0);


  /* book a 2D histogram for the scatter plot
   * TH2F is a ROOT class for 2D histograms hscat in an instance of that class
   * Arguments: TH2F("identifier", "some title", NumberBinsX, XMin, XMax, 
   *                                             NumberBinsY, YMin, YMax);
   */




  // Book a profile histogram
  // TProfile is a ROOT class for profile histograms, hprof is an instance 
  // of that class.
  // Arguments: 
  // TProfile("identifier", "some title", NumberBins, XMin, XMax, YMin, YMax, Option);
  // Note that YMin and YMax can be left blank/
  // The Option sets the treatment of errors (refer to the ROOT manual)
  // "Option" can be left blank, too.




 // Now all histograms have been booked and we can start the real work.

  for (int j=0; j<10000; j++) { // Repeat the experiment 10000 times.
    // Clear histogram "hran", i.e. set the content of each bin to zero.


    // Generate 100 random numbers for each experiment.



    // Unpack histogram into array content.



    for (int k=0;k<5;k++) {  // loop over all bins
      // Fill content of each bin into histogram

    }

    // Fill the scatter plot with the content of bin 2 and bin 4.

    // Fill the profile plot with the content of bin 2 and bin 4.

  }

  // Save all objects in the ROOT file and close it.
  hfile.Write();
  hfile.Close();

}

void erprop()
{ 
// Teste Fehlerfortpflanzung                            G. Quast, Dez. 2010
//     Fülle Quotienten und Differenz Gauss-verteilter Zufallszahlen 
//      in Histogram und vergleiche mit Gauss-Verteilungen

// some variables holding the input 
  const double mut=1.0;
  const double muy=0.5;
  const double sigt=0.3;
  const double sigy=0.1;
  const int Nrndm=10000;
 
// eventually, create a new ROOT file.
// TFile hfile("erprop.root","RECREATE","erprop");


double t,y;

// ----------------------------------------------------------------

// create a canvas, eventually with sub-pads for the three parts 
//  TCanvas *c1 ... 

// book a histograms, w. Nbins bins, range [xmin,xmax[
// TH1F* htovery = ...
// TH1F* hyovert = ...
// TH1F* htminusy = ...

// generate random t, y and fill into histograms in a loop

// normalised Gauss function
// TF1 *Ngauss=new ...

// draw histograms with Gauss functions and eventually some text into pads 


// eventually,  save all objects in the ROOT file and close it.
/*  
    c1->Write();
    hfile.Write();
    hfile.Close();
*/
}

void ranexp()
{
  Int_t NumRand=100000;   // Number of random numbers to be filled into
                          // a histogram.

  // Create a new ROOT file.
  TFile hfile("ranexp.root","RECREATE","pdfs");

  // Book histogram
  TH1F *h100 = new TH1F("h100","exponential decay",    100,0.0,10.0);

  //------------------------------------------------------------------------

  // Exponential distribution
  // Fill histogram h100 with exponential decay using transformation method



  //------------------------------------------------------------------------

  // Save all histograms in the ROOT file and close it.
  hfile.Write();
  hfile.Close();

}