Hi,
i’m trying to create a TH2D histogram,
and i get the following errors (errors happen for all my histograms):
error: unknown type name
'h_light_pass0'
h_light_pass0->Divide(h_light0);
^
error: cannot use arrow
operator on a type
h_light_pass0->Divide(h_light0);
Apparently, i am doing something very obvious and very wrong but I can’t figure it out…
Thanks in advance 
I attach my full code below (sorry for it being too long!):
#include <iostream>
#include <TString.h>
#include <TH1F.h>
#include <TTree.h>
#include <TFile.h>
#include "vector"
#include <TROOT.h>
#include <TStopwatch.h>
#include <TMath.h>
#include <stdlib.h>
#include <cmath>
#include "TH2.h"
#include <TClass.h>
using namespace std;
void finalobjects()
{
gROOT->Reset();
gROOT->SetStyle("Plain");
gStyle->SetOptStat(1);
gStyle->SetOptFit(1);
gStyle->SetPadColor(0);
gStyle->SetPalette(1);
TFile *f = TFile::Open("flatTree_TT_TuneCUETP8M2T4_13TeV-powheg-pythia8.root", "READ");
TTree *tree = (TTree*)f->Get("boosted/events");
vector<float> *jetMassSoftDrop(0);
vector<float> *jetMass(0);
vector<float> *jetEta(0);
vector<float> *jetPt(0);
vector<float> *jetMassSub0(0);
vector<float> *jetMassSub1(0);
vector<bool> *triggerBit(0);
vector<float> *jetNBSub(0);
vector<float> *jetIsBtag(0);
vector<float> *jetFlavor(0);
float mva;
int nJets, nBJets, nLeptons, category;
tree->SetBranchAddress("jetMassSoftDrop", &jetMassSoftDrop);
tree->SetBranchAddress("jetMass", &jetMass);
tree->SetBranchAddress("jetEta", &jetEta);
tree->SetBranchAddress("jetPt", &jetPt);
tree->SetBranchAddress("jetMassSub0", &jetMassSub0);
tree->SetBranchAddress("jetMassSub1", &jetMassSub1);
tree->SetBranchAddress("triggerBit", &triggerBit);
tree->SetBranchAddress("jetNBSub", &jetNBSub);
tree->SetBranchAddress("jetIsBtag", &jetIsBtag);
tree->SetBranchAddress("jetFlavor", &jetFlavor);
tree->SetBranchAddress("mva", &mva);
tree->SetBranchAddress("nJets",&nJets);
tree->SetBranchAddress("nBJets",&nBJets);
tree->SetBranchAddress("nLeptons",&nLeptons);
tree->SetBranchAddress("category", &category);
//histograms for 1st leading jet ( [0] )
TH2D *h_light0 = new TH2D ("h_light0", "h_light0",100, 0, 4, 100, 400, 1000);
TH2D *h_light_pass0 = new TH2D ("h_light_pass0", "h_light_pass0",100, 0, 4, 100, 400, 1000);
TH2D *h_c0 = new TH2D ("h_c0", "h_c0",100, 0, 4, 100, 400, 1000);
TH2D *h_c_pass0 = new TH2D ("h_c_pass0", "h_c_pass0",100, 0, 4, 100, 400, 1000);
TH2D *h_g0 = new TH2D ("h_g0", "h_g0",100, 0, 4, 100, 400, 1000);
TH2D *h_g_pass0 = new TH2D ("h_g_pass0", "h_gt_pass0",100, 0, 4, 100, 400, 1000);
//histograms for 2nd leading jet ( [1] )
TH2D *h_light1 = new TH2D ("h_light1", "h_light1",100, 0, 4, 100, 400, 1000);
TH2D *h_light_pass1 = new TH2D ("h_light_pass1", "h_light_pass1",100, 0, 4, 100, 400, 1000);
TH2D *h_c1 = new TH2D ("h_c1", "h_c1",100, 0, 4, 100, 400, 1000);
TH2D *h_c_pass1 = new TH2D ("h_c_pass1", "h_c_pass1",100, 0, 4, 100, 400, 1000);
TH2D *h_g1 = new TH2D ("h_g1", "h_g1",100, 0, 4, 100, 400, 1000);
TH2D *h_g_pass1 = new TH2D ("h_g_pass1", "h_g_pass1",100, 0, 4, 100, 400, 1000);
Long64_t N = tree->GetEntries();
for (Long64_t i=0;i<N;i++){
tree->GetEntry(i);
//mva>0.8
if ((nJets>1) && (nLeptons==0) && ((*jetPt)[1]>400) && (mva>0.8) && ((*triggerBit)[2]==true) && (category==2)){
if (((abs((*jetFlavor)[0])==1)||(abs((*jetFlavor)[0])==2)||(abs((*jetFlavor)[0])==3))
&& ((abs((*jetFlavor)[1])==1)||(abs((*jetFlavor)[1])==2)||(abs((*jetFlavor)[1])==3))){//------u,d,s quarks
h_light0->Fill(abs((*jetEta)[0]),(*jetPt)[0]);
h_light1->Fill(abs((*jetEta)[1]),(*jetPt)[1]);
if ((*jetIsBtag)[0]!=0 && (*jetIsBtag)[1]!=0){
h_light_pass0->Fill(abs((*jetEta)[0]),(*jetPt)[0]);
h_light_pass1->Fill(abs((*jetEta)[1]),(*jetPt)[1]);
}
}
else if ((abs((*jetFlavor)[0])==4)&&(abs((*jetFlavor)[1])==4)){//------c quark
h_c0->Fill(abs((*jetEta)[0]),(*jetPt)[0]);
h_c1->Fill(abs((*jetEta)[1]),(*jetPt)[1]);
if ((*jetIsBtag)[0]!=0 && (*jetIsBtag)[1]!=0){ // is btagged ?!?!?
h_c_pass0->Fill(abs((*jetEta)[0]),(*jetPt)[0]);
h_c_pass1->Fill(abs((*jetEta)[1]),(*jetPt)[1]);
}
}
else if ((*jetFlavor)[0]==21 && (*jetFlavor)[1]==21){//------gluons
h_g0->Fill(abs((*jetEta)[0]),(*jetPt)[0]);
h_g1->Fill(abs((*jetEta)[1]),(*jetPt)[1]);
if ((*jetIsBtag)[0]!=0 && (*jetIsBtag)[1]!=0){ // is btagged ?!?!?
h_g_pass0->Fill(abs((*jetEta)[0]),(*jetPt)[0]);
h_g_pass1->Fill(abs((*jetEta)[1]),(*jetPt)[1]);
}
}
}//end of 1st if
else continue;
}
}//end of for loop
h_light_pass0->Divide(h_light0);
h_light_pass1->Divide(h_light1);
h_c_pass0->Divide(h_c0);
h_c_pass1->Divide(h_c1);
h_g_pass0->Divide(h_g0);
h_g_pass1->Divide(h_g1);
TCanvas *can1 = new TCanvas ("can1", "can1", 600, 600);
h_light_pass0->SetTitle("light quarks: u,d,s");
h_light_pass0->GetXaxis()->SetTitle("jetPT [GeV]")
h_light_pass0->GetYaxis()->SetTitle("|eta|");
//_light_pass0->GetYaxis()->SetRangeUser(-0.08,0.08);
h_light_pass0->Draw();
h_light_pass1->Draw("sames");
TCanvas *can2 = new TCanvas ("can2", "can2", 600, 600);
h_c_pass0->SetTitle("c quarks");
h_c_pass0->GetXaxis()->SetTitle("jetPT [GeV]")
h_c_pass0->GetYaxis()->SetTitle("|eta|");
//h_c_pass0->GetYaxis()->SetRangeUser(-0.08,0.08);
h_c_pass0->Draw();
h_c_pass1->Draw("sames");
TCanvas *can3 = new TCanvas ("can3", "can3", 600, 600);
h_g_pass0->SetTitle("gluons");
h_g_pass0->GetXaxis()->SetTitle("jetPT [GeV]")
h_g_pass0->GetYaxis()->SetTitle("|eta|");
//h_g_pass0->GetYaxis()->SetRangeUser(-0.08,0.08);
h_g_pass0->Draw();
h_g_pass1->Draw("sames");
}