{
// Example of the fit of correction function for B=8 events sample

   gROOT->SetStyle("Plain");
   gStyle->SetOptTitle(0);

  gStyle->SetPadRightMargin(0.01);
  gStyle->SetPadTopMargin(0.02);
  gStyle->SetPadLeftMargin(0.16);
  gStyle->SetPadBottomMargin(0.14);
  gStyle->SetLabelSize(0.05, "xy");
  gStyle->SetTitleSize(0.07, "x");
  gStyle->SetTitleSize(0.07, "y");
  gStyle->SetTitleOffset(1.1, "y");
  gStyle->SetTitleOffset(0.8, "x");
  gStyle->SetLabelOffset(0.02, "y");

   TCanvas *ceta = new TCanvas("c_eta_correction_fit_B8", "eta_correction_fit",600,400);
   
   TGraph *graph = new TGraph(83);
   graph->SetName("Graph");
   graph->SetTitle("Graph");
   graph->SetFillColor(1);
   graph->SetLineStyle(0);
   graph->SetMarkerColor(2);
   graph->SetMarkerStyle(24);
   graph->SetMarkerSize(1.3);
   graph->SetPoint(0,-2.075,0.544807);
   graph->SetPoint(1,-2.025,0.896559);
   graph->SetPoint(2,-1.975,1.4641);
   graph->SetPoint(3,-1.925,1.96396);
   graph->SetPoint(4,-1.875,2.36052);
   graph->SetPoint(5,-1.825,2.93644);
   graph->SetPoint(6,-1.775,3.18122);
   graph->SetPoint(7,-1.725,3.45987);
   graph->SetPoint(8,-1.675,3.21259);
   graph->SetPoint(9,-1.625,3.28903);
   graph->SetPoint(10,-1.575,3.18383);
   graph->SetPoint(11,-1.525,3.10906);
   graph->SetPoint(12,-1.475,3.06555);
   graph->SetPoint(13,-1.425,2.95667);
   graph->SetPoint(14,-1.375,2.88711);
   graph->SetPoint(15,-1.325,2.77219);
   graph->SetPoint(16,-1.275,2.80976);
   graph->SetPoint(17,-1.225,2.66843);
   graph->SetPoint(18,-1.175,2.56885);
   graph->SetPoint(19,-1.125,2.50648);
   graph->SetPoint(20,-1.075,2.44461);
   graph->SetPoint(21,-1.025,2.52432);
   graph->SetPoint(22,-0.975,2.46458);
   graph->SetPoint(23,-0.925,2.31144);
   graph->SetPoint(24,-0.875,2.30721);
   graph->SetPoint(25,-0.825,2.25425);
   graph->SetPoint(26,-0.775,2.23402);
   graph->SetPoint(27,-0.725,2.15652);
   graph->SetPoint(28,-0.675,2.15321);
   graph->SetPoint(29,-0.625,2.06295);
   graph->SetPoint(30,-0.575,2.04883);
   graph->SetPoint(31,-0.525,2.05832);
   graph->SetPoint(32,-0.475,2.02008);
   graph->SetPoint(33,-0.425,1.99422);
   graph->SetPoint(34,-0.375,1.94805);
   graph->SetPoint(35,-0.325,2.0315);
   graph->SetPoint(36,-0.275,2.05993);
   graph->SetPoint(37,-0.225,1.92324);
   graph->SetPoint(38,-0.175,1.98348);
   graph->SetPoint(39,-0.125,1.94066);
   graph->SetPoint(40,-0.075,1.97398);
   graph->SetPoint(41,-0.025,1.89757);
   graph->SetPoint(42,0.025,1.99236);
   graph->SetPoint(43,0.075,1.93972);
   graph->SetPoint(44,0.125,2.0077);
   graph->SetPoint(45,0.175,1.94182);
   graph->SetPoint(46,0.225,1.95855);
   graph->SetPoint(47,0.275,1.99164);
   graph->SetPoint(48,0.325,1.97962);
   graph->SetPoint(49,0.375,1.99774);
   graph->SetPoint(50,0.425,2.05995);
   graph->SetPoint(51,0.475,2.06341);
   graph->SetPoint(52,0.525,2.05785);
   graph->SetPoint(53,0.575,2.07149);
   graph->SetPoint(54,0.625,2.12861);
   graph->SetPoint(55,0.675,2.16791);
   graph->SetPoint(56,0.725,2.16663);
   graph->SetPoint(57,0.775,2.27864);
   graph->SetPoint(58,0.825,2.21726);
   graph->SetPoint(59,0.875,2.21812);
   graph->SetPoint(60,0.925,2.40544);
   graph->SetPoint(61,0.975,2.42597);
   graph->SetPoint(62,1.025,2.55526);
   graph->SetPoint(63,1.075,2.56734);
   graph->SetPoint(64,1.125,2.45037);
   graph->SetPoint(65,1.175,2.65331);
   graph->SetPoint(66,1.225,2.60673);
   graph->SetPoint(67,1.275,2.70685);
   graph->SetPoint(68,1.325,2.76859);
   graph->SetPoint(69,1.375,2.88394);
   graph->SetPoint(70,1.425,2.99477);
   graph->SetPoint(71,1.475,3.08557);
   graph->SetPoint(72,1.525,3.24468);
   graph->SetPoint(73,1.575,3.28272);
   graph->SetPoint(74,1.625,3.22019);
   graph->SetPoint(75,1.675,3.12828);
   graph->SetPoint(76,1.725,3.10207);
   graph->SetPoint(77,1.775,3.0085);
   graph->SetPoint(78,1.825,2.64098);
   graph->SetPoint(79,1.875,2.16169);
   graph->SetPoint(80,1.925,1.71934);
   graph->SetPoint(81,1.975,1.17499);
   graph->SetPoint(82,2.025,0.660596);
   
   TH1 *Graph1 = new TH1F("Graph1","Graph",100,-3,3);
   Graph1->SetMinimum(0);
   Graph1->SetMaximum(3.6);
   Graph1->SetDirectory(0);
   Graph1->SetStats(0);
   Graph1->GetXaxis()->SetTitle("#eta");
   Graph1->GetYaxis()->SetTitle("correction");
   graph->SetHistogram(Graph1);
   
   graph->Draw("ap");
   
   TF1 *etacorr3 = new TF1("etacorr3","[0]+[1]*x*x+[2]*x*x*x*x",-1.7,1.7);
   etacorr3->SetFillColor(19);
   etacorr3->SetFillStyle(0);
   etacorr3->SetLineColor(2);
   etacorr3->SetLineWidth(3);
   etacorr3->SetChisquare(0.0841948);
   etacorr3->SetParameter(0,1.93512);
   etacorr3->SetParError(0,0.325865);
   etacorr3->SetParLimits(0,0,0);
   etacorr3->SetParameter(1,0.491503);
   etacorr3->SetParError(1,0.765746);
   etacorr3->SetParLimits(1,0,0);
   etacorr3->SetParameter(2,0.00157914);
   etacorr3->SetParError(2,0.307598);
   etacorr3->SetParLimits(2,0,0);
   etacorr3->Draw("lsame");
   
   TF1 *etacorr3 = new TF1("etacorr3","[0]+[1]*x*x+[2]*x*x*x*x",-1.7,1.7);
   etacorr3->SetFillColor(19);
   etacorr3->SetFillStyle(0);
   etacorr3->SetLineColor(2);
   etacorr3->SetLineWidth(3);
   etacorr3->SetChisquare(0.0841948);
   etacorr3->SetParameter(0,1.93512);
   etacorr3->SetParError(0,0.325865);
   etacorr3->SetParLimits(0,0,0);
   etacorr3->SetParameter(1,0.491503);
   etacorr3->SetParError(1,0.765746);
   etacorr3->SetParLimits(1,0,0);
   etacorr3->SetParameter(2,0.00157914);
   etacorr3->SetParError(2,0.307598);
   etacorr3->SetParLimits(2,0,0);
   etacorr3->Draw("lsame");
   
   graph = new TGraph(95);
   graph->SetName("Graph");
   graph->SetTitle("Graph");
   graph->SetFillColor(1);
   graph->SetMarkerColor(4);
   graph->SetMarkerStyle(26);
   graph->SetPoint(0,-2.375,0.631062);
   graph->SetPoint(1,-2.325,1.04738);
   graph->SetPoint(2,-2.275,1.56126);
   graph->SetPoint(3,-2.225,2.08536);
   graph->SetPoint(4,-2.175,2.63148);
   graph->SetPoint(5,-2.125,3.02906);
   graph->SetPoint(6,-2.075,3.17332);
   graph->SetPoint(7,-2.025,3.19259);
   graph->SetPoint(8,-1.975,3.34567);
   graph->SetPoint(9,-1.925,3.13964);
   graph->SetPoint(10,-1.875,2.97636);
   graph->SetPoint(11,-1.825,3.00838);
   graph->SetPoint(12,-1.775,2.95879);
   graph->SetPoint(13,-1.725,2.87588);
   graph->SetPoint(14,-1.675,2.76881);
   graph->SetPoint(15,-1.625,2.7809);
   graph->SetPoint(16,-1.575,2.69171);
   graph->SetPoint(17,-1.525,2.56477);
   graph->SetPoint(18,-1.475,2.47849);
   graph->SetPoint(19,-1.425,2.38744);
   graph->SetPoint(20,-1.375,2.38278);
   graph->SetPoint(21,-1.325,2.3139);
   graph->SetPoint(22,-1.275,2.30711);
   graph->SetPoint(23,-1.225,2.20853);
   graph->SetPoint(24,-1.175,2.12653);
   graph->SetPoint(25,-1.125,2.09815);
   graph->SetPoint(26,-1.075,2.07964);
   graph->SetPoint(27,-1.025,2.064);
   graph->SetPoint(28,-0.975,2.09169);
   graph->SetPoint(29,-0.925,1.98674);
   graph->SetPoint(30,-0.875,1.97532);
   graph->SetPoint(31,-0.825,1.92385);
   graph->SetPoint(32,-0.775,1.85244);
   graph->SetPoint(33,-0.725,1.79524);
   graph->SetPoint(34,-0.675,1.84176);
   graph->SetPoint(35,-0.625,1.77143);
   graph->SetPoint(36,-0.575,1.75843);
   graph->SetPoint(37,-0.525,1.76604);
   graph->SetPoint(38,-0.475,1.77622);
   graph->SetPoint(39,-0.425,1.77294);
   graph->SetPoint(40,-0.375,1.75062);
   graph->SetPoint(41,-0.325,1.75452);
   graph->SetPoint(42,-0.275,1.74779);
   graph->SetPoint(43,-0.225,1.67111);
   graph->SetPoint(44,-0.175,1.67142);
   graph->SetPoint(45,-0.125,1.64948);
   graph->SetPoint(46,-0.075,1.63481);
   graph->SetPoint(47,-0.025,1.7028);
   graph->SetPoint(48,0.025,1.73367);
   graph->SetPoint(49,0.075,1.68881);
   graph->SetPoint(50,0.125,1.71559);
   graph->SetPoint(51,0.175,1.65364);
   graph->SetPoint(52,0.225,1.71978);
   graph->SetPoint(53,0.275,1.72565);
   graph->SetPoint(54,0.325,1.76236);
   graph->SetPoint(55,0.375,1.74428);
   graph->SetPoint(56,0.425,1.75906);
   graph->SetPoint(57,0.475,1.77603);
   graph->SetPoint(58,0.525,1.78176);
   graph->SetPoint(59,0.575,1.78879);
   graph->SetPoint(60,0.625,1.82243);
   graph->SetPoint(61,0.675,1.84343);
   graph->SetPoint(62,0.725,1.89924);
   graph->SetPoint(63,0.775,1.89345);
   graph->SetPoint(64,0.825,1.87871);
   graph->SetPoint(65,0.875,1.88479);
   graph->SetPoint(66,0.925,1.97349);
   graph->SetPoint(67,0.975,2.00887);
   graph->SetPoint(68,1.025,2.05581);
   graph->SetPoint(69,1.075,2.06384);
   graph->SetPoint(70,1.125,2.09885);
   graph->SetPoint(71,1.175,2.18681);
   graph->SetPoint(72,1.225,2.14933);
   graph->SetPoint(73,1.275,2.18609);
   graph->SetPoint(74,1.325,2.3368);
   graph->SetPoint(75,1.375,2.40545);
   graph->SetPoint(76,1.425,2.41618);
   graph->SetPoint(77,1.475,2.43173);
   graph->SetPoint(78,1.525,2.49223);
   graph->SetPoint(79,1.575,2.58909);
   graph->SetPoint(80,1.625,2.67781);
   graph->SetPoint(81,1.675,2.7506);
   graph->SetPoint(82,1.725,2.79811);
   graph->SetPoint(83,1.775,2.91661);
   graph->SetPoint(84,1.825,3.0708);
   graph->SetPoint(85,1.875,3.13702);
   graph->SetPoint(86,1.925,3.11386);
   graph->SetPoint(87,1.975,3.16534);
   graph->SetPoint(88,2.025,3.06126);
   graph->SetPoint(89,2.075,2.88271);
   graph->SetPoint(90,2.125,2.71789);
   graph->SetPoint(91,2.175,2.22833);
   graph->SetPoint(92,2.225,1.85506);
   graph->SetPoint(93,2.275,1.34277);
   graph->SetPoint(94,2.325,0.813182);
   graph->Draw("p");
   
   TF1 *etacorr2 = new TF1("etacorr2","[0]+[1]*x*x+[2]*x*x*x*x",-2,2);
   etacorr2->SetFillColor(19);
   etacorr2->SetFillStyle(0);
   etacorr2->SetLineColor(4);
   etacorr2->SetLineWidth(3);
   etacorr2->SetChisquare(0.0553475);
   etacorr2->SetParameter(0,1.68748);
   etacorr2->SetParError(0,0.281138);
   etacorr2->SetParLimits(0,0,0);
   etacorr2->SetParameter(1,0.314859);
   etacorr2->SetParError(1,0.484599);
   etacorr2->SetParLimits(1,0,0);
   etacorr2->SetParameter(2,0.0231178);
   etacorr2->SetParError(2,0.142079);
   etacorr2->SetParLimits(2,0,0);
   etacorr2->Draw("lsame");
   
   graph = new TGraph(117);
   graph->SetName("Graph");
   graph->SetTitle("Graph");
   graph->SetFillColor(1);
   graph->SetMarkerStyle(25);
   graph->SetMarkerSize(1.3);
   graph->SetPoint(0,-2.925,0.657331);
   graph->SetPoint(1,-2.875,1.12552);
   graph->SetPoint(2,-2.825,1.57202);
   graph->SetPoint(3,-2.775,2.10296);
   graph->SetPoint(4,-2.725,2.53354);
   graph->SetPoint(5,-2.675,2.91735);
   graph->SetPoint(6,-2.625,3.18346);
   graph->SetPoint(7,-2.575,3.13231);
   graph->SetPoint(8,-2.525,3.05652);
   graph->SetPoint(9,-2.475,3.02747);
   graph->SetPoint(10,-2.425,2.93835);
   graph->SetPoint(11,-2.375,2.95351);
   graph->SetPoint(12,-2.325,2.73419);
   graph->SetPoint(13,-2.275,2.67417);
   graph->SetPoint(14,-2.225,2.55724);
   graph->SetPoint(15,-2.175,2.55185);
   graph->SetPoint(16,-2.125,2.52833);
   graph->SetPoint(17,-2.075,2.38758);
   graph->SetPoint(18,-2.025,2.31837);
   graph->SetPoint(19,-1.975,2.24177);
   graph->SetPoint(20,-1.925,2.26228);
   graph->SetPoint(21,-1.875,2.05575);
   graph->SetPoint(22,-1.825,2.10995);
   graph->SetPoint(23,-1.775,2.041);
   graph->SetPoint(24,-1.725,2.00476);
   graph->SetPoint(25,-1.675,1.89064);
   graph->SetPoint(26,-1.625,1.95288);
   graph->SetPoint(27,-1.575,1.88557);
   graph->SetPoint(28,-1.525,1.75309);
   graph->SetPoint(29,-1.475,1.78226);
   graph->SetPoint(30,-1.425,1.73748);
   graph->SetPoint(31,-1.375,1.73644);
   graph->SetPoint(32,-1.325,1.70031);
   graph->SetPoint(33,-1.275,1.71877);
   graph->SetPoint(34,-1.225,1.64816);
   graph->SetPoint(35,-1.175,1.59702);
   graph->SetPoint(36,-1.125,1.60633);
   graph->SetPoint(37,-1.075,1.57382);
   graph->SetPoint(38,-1.025,1.57795);
   graph->SetPoint(39,-0.975,1.51393);
   graph->SetPoint(40,-0.925,1.5031);
   graph->SetPoint(41,-0.875,1.53778);
   graph->SetPoint(42,-0.825,1.49753);
   graph->SetPoint(43,-0.775,1.50206);
   graph->SetPoint(44,-0.725,1.47304);
   graph->SetPoint(45,-0.675,1.47844);
   graph->SetPoint(46,-0.625,1.46994);
   graph->SetPoint(47,-0.575,1.4408);
   graph->SetPoint(48,-0.525,1.45828);
   graph->SetPoint(49,-0.475,1.43864);
   graph->SetPoint(50,-0.425,1.44834);
   graph->SetPoint(51,-0.375,1.41601);
   graph->SetPoint(52,-0.325,1.44002);
   graph->SetPoint(53,-0.275,1.43632);
   graph->SetPoint(54,-0.225,1.40175);
   graph->SetPoint(55,-0.175,1.39692);
   graph->SetPoint(56,-0.125,1.4362);
   graph->SetPoint(57,-0.075,1.38315);
   graph->SetPoint(58,-0.025,1.41155);
   graph->SetPoint(59,0.025,1.42821);
   graph->SetPoint(60,0.075,1.37534);
   graph->SetPoint(61,0.125,1.38684);
   graph->SetPoint(62,0.175,1.43386);
   graph->SetPoint(63,0.225,1.42574);
   graph->SetPoint(64,0.275,1.41853);
   graph->SetPoint(65,0.325,1.39721);
   graph->SetPoint(66,0.375,1.42265);
   graph->SetPoint(67,0.425,1.42945);
   graph->SetPoint(68,0.475,1.47088);
   graph->SetPoint(69,0.525,1.42536);
   graph->SetPoint(70,0.575,1.4096);
   graph->SetPoint(71,0.625,1.4463);
   graph->SetPoint(72,0.675,1.4629);
   graph->SetPoint(73,0.725,1.49793);
   graph->SetPoint(74,0.775,1.51828);
   graph->SetPoint(75,0.825,1.51486);
   graph->SetPoint(76,0.875,1.48824);
   graph->SetPoint(77,0.925,1.50331);
   graph->SetPoint(78,0.975,1.56948);
   graph->SetPoint(79,1.025,1.59867);
   graph->SetPoint(80,1.075,1.60822);
   graph->SetPoint(81,1.125,1.60588);
   graph->SetPoint(82,1.175,1.61429);
   graph->SetPoint(83,1.225,1.61926);
   graph->SetPoint(84,1.275,1.647);
   graph->SetPoint(85,1.325,1.70888);
   graph->SetPoint(86,1.375,1.77215);
   graph->SetPoint(87,1.425,1.75857);
   graph->SetPoint(88,1.475,1.78465);
   graph->SetPoint(89,1.525,1.75962);
   graph->SetPoint(90,1.575,1.83157);
   graph->SetPoint(91,1.625,1.92293);
   graph->SetPoint(92,1.675,1.91269);
   graph->SetPoint(93,1.725,1.96618);
   graph->SetPoint(94,1.775,2.04584);
   graph->SetPoint(95,1.825,2.06913);
   graph->SetPoint(96,1.875,2.13889);
   graph->SetPoint(97,1.925,2.20871);
   graph->SetPoint(98,1.975,2.28661);
   graph->SetPoint(99,2.025,2.38783);
   graph->SetPoint(100,2.075,2.41312);
   graph->SetPoint(101,2.125,2.46593);
   graph->SetPoint(102,2.175,2.59648);
   graph->SetPoint(103,2.225,2.73188);
   graph->SetPoint(104,2.275,2.78689);
   graph->SetPoint(105,2.325,2.90239);
   graph->SetPoint(106,2.375,2.92316);
   graph->SetPoint(107,2.425,3.00471);
   graph->SetPoint(108,2.475,3.07871);
   graph->SetPoint(109,2.525,3.04478);
   graph->SetPoint(110,2.575,3.03786);
   graph->SetPoint(111,2.625,2.88004);
   graph->SetPoint(112,2.675,2.64055);
   graph->SetPoint(113,2.725,2.35993);
   graph->SetPoint(114,2.775,1.80913);
   graph->SetPoint(115,2.825,1.31117);
   graph->SetPoint(116,2.875,0.854356);
   graph->Draw("p");
   
   TF1 *etacorr1 = new TF1("etacorr1","[0]+[1]*x*x+[2]*x*x*x*x",-2.5,2.5);
   etacorr1->SetFillColor(19);
   etacorr1->SetFillStyle(0);
   etacorr1->SetLineWidth(3);
   etacorr1->SetChisquare(0.0550108);
   etacorr1->SetParameter(0,1.40835);
   etacorr1->SetParError(0,0.229466);
   etacorr1->SetParLimits(0,0,0);
   etacorr1->SetParameter(1,0.118329);
   etacorr1->SetParError(1,0.25541);
   etacorr1->SetParLimits(1,0,0);
   etacorr1->SetParameter(2,0.0259506);
   etacorr1->SetParError(2,0.0484484);
   etacorr1->SetParLimits(2,0,0);
   etacorr1->Draw("lsame");

   ceta->Modified();
   
}