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Reference Guide
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:80
#define gROOT
Definition: TROOT.h:404
char * Form(const char *fmt,...)
Formats a string in a circular formatting buffer.
Definition: TString.cxx:2452
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:574
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
double T(double x)
Definition: ChebyshevPol.h:34
Rene Brun

Definition in file basic2.C.