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loopdir11.C
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1/// \file
2/// \ingroup tutorial_io
3/// \notebook -nodraw
4/// Example of script to loop on all the objects of a ROOT file directory
5/// and print on Postscript all TH1 derived objects.
6/// This script uses the file generated by tutorial hsimple.C
7///
8/// \macro_image
9/// \macro_code
10///
11/// \author Rene Brun
12
13void loopdir11() {
14 TFile *f1 = TFile::Open("hsimple.root");
15 TCanvas c1;
16 c1.Print("hsimple.ps[");
17 for(auto k : *f1->GetListOfKeys()) {
18 TKey *key = static_cast<TKey*>(k);
19 TClass *cl = gROOT->GetClass(key->GetClassName());
20 if (!cl->InheritsFrom("TH1")) continue;
21 TH1 *h = key->ReadObject<TH1>();
22 h->Draw();
23 c1.Print("hsimple.ps");
24 }
25 c1.Print("hsimple.ps]");
26}
#define h(i)
Definition RSha256.hxx:106
#define gROOT
Definition TROOT.h:406
The Canvas class.
Definition TCanvas.h:23
TClass instances represent classes, structs and namespaces in the ROOT type system.
Definition TClass.h:80
Bool_t InheritsFrom(const char *cl) const
Return kTRUE if this class inherits from a class with name "classname".
Definition TClass.cxx:4851
static TClass * GetClass(const char *name, Bool_t load=kTRUE, Bool_t silent=kFALSE)
Static method returning pointer to TClass of the specified class name.
Definition TClass.cxx:2957
A ROOT file is a suite of consecutive data records (TKey instances) with a well defined format.
Definition TFile.h:54
static TFile * Open(const char *name, Option_t *option="", const char *ftitle="", Int_t compress=ROOT::RCompressionSetting::EDefaults::kUseCompiledDefault, Int_t netopt=0)
Create / open a file.
Definition TFile.cxx:3997
TH1 is the base class of all histogram classes in ROOT.
Definition TH1.h:58
virtual void Draw(Option_t *option="")
Draw this histogram with options.
Definition TH1.cxx:3073
Book space in a file, create I/O buffers, to fill them, (un)compress them.
Definition TKey.h:28
T * ReadObject()
To read an object (non deriving from TObject) from the file.
Definition TKey.h:104
virtual const char * GetClassName() const
Definition TKey.h:76
void Print(const char *filename="") const override
Save Pad contents in a file in one of various formats.
Definition TPad.cxx:4692
return c1
Definition legend1.C:41
TF1 * f1
Definition legend1.C:11
UInt_t GetListOfKeys(TList &keys, TString inherits, TDirectory *dir=0)
Definition tmvaglob.cxx:382