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mp105_processEntryList.C File Reference

Detailed Description

View in nbviewer Open in SWAN Illustrate the usage of the multiproc to process TEntryList with the H1 analysis example.

#include "TString.h"
#include "TROOT.h"
#include "TTree.h"
#include "TH1F.h"
#include "TH2F.h"
#include "TEntryList.h"
#include "TTreeReader.h"
#include "TSystem.h"
#include "TMath.h"
#include "TCanvas.h"
#include "TStyle.h"
#include "TF1.h"
#include "TLine.h"
#include "TPaveStats.h"
#include "TStopwatch.h"
static std::string tutname = "mp105_processEntryList: ";
static std::string logfile = "mp105_processEntryList.log";
static RedirectHandle_t gRH;
std::vector<std::string> files = {"http://root.cern.ch/files/h1/dstarmb.root",
int mp105_processEntryList()
// MacOSX may generate connection to WindowServer errors
#include "mp_H1_lambdas.C"
std::cout << tutname << "creating the entry list \n";
auto sumElist = pool.Process(files, doH1fillList, "h42");
// Print the entry list
if (sumElist) {
} else {
std::cout << tutname << " ERROR creating the entry list \n";
return -1;
// Time taken
// Let's analyse H1 with the list
std::cout << tutname << "processing the entry list with a lambda \n";
// Run the analysis
auto hListFun = pool.Process(files, doH1useList, *sumElist, "h42");
// Check the output
if (checkH1(hListFun) < 0)
return -1;
// Do the fit
if (doFit(hListFun, logfile.c_str()) < 0)
return -1;
// Run the analysis with a selector
TString selectorPath = gROOT->GetTutorialDir();
selectorPath += "/tree/h1analysisTreeReader.C+";
std::cout << tutname << "processing the entry list with selector '" << selectorPath << "'\n";
auto sel = TSelector::GetSelector(selectorPath);
// In a second run we use sel
gSystem->RedirectOutput(logfile.c_str(), "w", &gRH);
auto hListSel = pool.Process(files, *sel, *sumElist, "h42");
gSystem->RedirectOutput(0, 0, &gRH);
// Check the output
if (checkH1(hListSel) < 0)
return -1;
// Do the fit
if (doFit(hListSel, logfile.c_str()) < 0)
return -1;
return 0;
const Bool_t kTRUE
Definition RtypesCore.h:100
#define gROOT
Definition TROOT.h:404
R__EXTERN TSystem * gSystem
Definition TSystem.h:559
This class provides an interface to process a TTree dataset in parallel with multi-process technology...
static TSelector * GetSelector(const char *filename)
The code in filename is loaded (interpreted or compiled, see below), filename must contain a valid cl...
Stopwatch class.
Definition TStopwatch.h:28
void Start(Bool_t reset=kTRUE)
Start the stopwatch.
void Print(Option_t *option="") const
Print the real and cpu time passed between the start and stop events.
Basic string class.
Definition TString.h:136
virtual Int_t RedirectOutput(const char *name, const char *mode="a", RedirectHandle_t *h=nullptr)
Redirect standard output (stdout, stderr) to the specified file.
Definition TSystem.cxx:1713
<a href="https://nbviewer.jupyter.org/url/root.cern/doc/master/notebooks/mp_H1_lambdas....
Gerardo Ganis

Definition in file mp105_processEntryList.C.