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basic2.C File Reference

Detailed Description

View in nbviewer Open in SWAN Create can ntuple reading data from an ascii file.

This macro is a variant of basic.C

void basic2() {
TString dir = gROOT->GetTutorialDir();
TFile *f = new TFile("basic2.root","RECREATE");
TH1F *h1 = new TH1F("h1","x distribution",100,-4,4);
TTree *T = new TTree("ntuple","data from ascii file");
Long64_t nlines = T->ReadFile(Form("%sbasic.dat",dir.Data()),"x:y:z");
printf(" found %lld points\n",nlines);
#define f(i)
Definition RSha256.hxx:104
long long Long64_t
Definition RtypesCore.h:73
#define gROOT
Definition TROOT.h:406
char * Form(const char *fmt,...)
A ROOT file is a suite of consecutive data records (TKey instances) with a well defined format.
Definition TFile.h:54
1-D histogram with a float per channel (see TH1 documentation)}
Definition TH1.h:575
Basic string class.
Definition TString.h:136
const char * Data() const
Definition TString.h:369
TString & ReplaceAll(const TString &s1, const TString &s2)
Definition TString.h:692
TString & Append(const char *cs)
Definition TString.h:564
A TTree represents a columnar dataset.
Definition TTree.h:79
TH1F * h1
Definition legend1.C:5
Rene Brun

Definition in file basic2.C.