/*

FakePhysicist.com
admin@fakephysicist.com
18 April 2017

Compile with:
g++ rootwrite.cpp -o rootwrite `root-config --cflags --libs`

*/

#include <iostream>
#include <iomanip>
#include <cmath>
#include <fstream>
#include <vector>
#include <cstring>

/****** Include the required ROOT Classes *****/
#include "TRandom.h"
#include "TFile.h"
#include "TTree.h"

using namespace std;

int main() {

  const int points = 11;
  int sets = 100;
  double maxV = 5.;
  double minV = 0.;
  double res = 1000.;
  double v_voltage[points] = {
    0.,0.5,1.0,1.5,2.0,2.5,3.0,3.5,4.0,4.5,5.0
  };
  
  // Create a new ROOT File
  TFile *fileOut = new TFile("/media/surya/Surya_1/Online/FakePhysicist/5.ROOTFiles/test.root","RECREATE");

  // Create a tree in which the data will be written
  TTree *outTree = new TTree("testTree","testTree");
  // Arguments: name, title

  unsigned int pointIn;		// Array length
  float reading[points];	// Data array

  // Creating branch inside the tree to store data
  outTree->Branch("pointIn",&pointIn,"pointIn/I"); // Variable for data length: This is very important. Without this the next branch will not work.
  outTree->Branch("reading",reading,"reading[pointIn]/F"); // Data array: Note the length of array
  
  for(int jk=0;jk<sets;jk++) {
    for(int ij=0;ij<points;ij++) {
      if(jk == 0) {
	reading[ij] = v_voltage[ij];	// First entry is the voltage points
      } else {
	reading[ij] = gRandom->Gaus(v_voltage[ij]/res,0.00005); // Rest entries are current readings
      }
    }
    pointIn = points;		// Setting the array length
    outTree->Fill();		// Filling the entry
  }

  fileOut->cd();		// At the end: Call the file
  outTree->Write();		// Write the tree into it
  fileOut->Close();		// Close the tree
  
  return 0;
}