Please read tips for efficient and successful posting and posting code
_ROOT Version_Not Provided
Platform: Ubuntu via WSL
Compiler: Not Provided
When I run the following code:
TFile *file = TFile::Open("https://atlas-opendata.web.cern.ch/atlas-opendata/samples/2020/1largeRjet1lep/MC/mc_361106.Zee.1largeRjet1lep.root");
TTree *baum = (TTree*) file->Get("mini");
UInt_t lepton_n = -1;
baum->SetBranchAddress("lep_n", &lepton_n);
TCanvas *canv = new TCanvas("CAnvas", "canvas", 800, 600);
TH1F *hist = new TH1F("variable","Example plot: Number of leptons; Number of leptons ; Events ",5,-0.5,4.5);
int nentries, nbytes, i;
nentries = (Int_t)baum->GetEntries();
for (i=0; i<nentries;i++){
nbytes = baum->GetEntry(i);
hist->Fill(lepton_n);
}
hist->SetFillColor(kRed);
hist->Draw();
canv->Draw();
I get this error:
/home/advait/main.C:5:1: error: unknown type name 'baum' baum->SetBranchAddress("lep_n", &lepton_n); ^ /home/advait/main.C:5:5: error: cannot use arrow operator on a type baum->SetBranchAddress("lep_n", &lepton_n); ^ /home/advait/main.C:9:1: error: C++ requires a type specifier for all declarations nentries = (Int_t)baum->GetEntries(); ^ /home/advait/main.C:11:1: error: expected unqualified-id for (i=0; i<nentries;i++){ ^ /home/advait/main.C:17:1: error: unknown type name 'hist' hist->SetFillColor(kRed); ^ /home/advait/main.C:17:5: error: cannot use arrow operator on a type hist->SetFillColor(kRed); ^ /home/advait/main.C:18:1: error: unknown type name 'hist' hist->Draw(); ^ /home/advait/main.C:18:5: error: cannot use arrow operator on a type hist->Draw(); ^ /home/advait/main.C:19:1: error: unknown type name 'canv' canv->Draw(); ^ /home/advait/main.C:19:5: error: cannot use arrow operator on a type canv->Draw();
Which is strange. I get this error even for the simplest of things. Whats up here?