Fill histograms in parallel and write them on file.
This example expresses the parallelism of the mt001_fillHistos.C tutorial with multiprocessing techniques.
const UInt_t nNumbers = 20000000U;
{
auto workItem = [](
UInt_t workerID) {
TFile f(
Form(
"myFile_mp001_%u.root", workerID),
"RECREATE");
TH1F h(
Form(
"myHisto_%u", workerID),
"The Histogram", 64, -4, 4);
for (
UInt_t i = 0; i < nNumbers; ++i) {
h.Fill(workerRndm.Gaus());
}
return 0;
};
return 0;
}
char * Form(const char *fmt,...)
Formats a string in a circular formatting buffer.
This class provides a simple interface to execute the same task multiple times in parallel,...
A pseudo container class which is a generator of indices.
A ROOT file is composed of a header, followed by consecutive data records (TKey instances) with a wel...
1-D histogram with a float per channel (see TH1 documentation)}
Random number generator class based on M.
- Date
- January 2016
- Author
- Danilo Piparo
Definition in file mp001_fillHistos.C.