Read an sqlite3 databases with RDataFrame and plot statistics on ROOT downloads.
Plot the downloads of different ROOT versions reading a remote sqlite3 file with RSqliteDS. Then a TH1F histogram is created and filled using a lambda expression which receives the recorded values in the "version" column of the sqlite3 database. The histogram shows the usage of the ROOT development version.
void df030_SQliteVersionsOfROOT() {
auto rdf =
ROOT::RDF::FromSqlite(
"http://root.cern/files/root_download_stats.sqlite",
"SELECT Version FROM accesslog;");
TH1F hVersionOfRoot(
"hVersionOfRoot",
"Development Versions of ROOT", 8, 0, -1);
auto fillVersionHisto = [&hVersionOfRoot] (const std::string &version) {
TString shortVersion(copyVersion(0,4));
hVersionOfRoot.Fill(shortVersion, 1);
};
rdf.Foreach( fillVersionHisto, { "Version" } );
auto VersionOfRootHistogram =
new TCanvas();
hVersionOfRoot.GetXaxis()->LabelsOption("a");
hVersionOfRoot.LabelsDeflate("X");
hVersionOfRoot.DrawClone("");
}
R__EXTERN TStyle * gStyle
1-D histogram with a float per channel (see TH1 documentation)
void SetOptStat(Int_t stat=1)
The type of information printed in the histogram statistics box can be selected via the parameter mod...
RDataFrame FromSqlite(std::string_view fileName, std::string_view query)
Factory method to create a SQlite RDataFrame.
- Date
- August 2018
- Author
- Alexandra-Maria Dobrescu
Definition in file df030_SQliteVersionsOfROOT.C.
