ROOT Version: 6.36.04
Built for linuxarm64 on Aug 25 2025, 00:00:00
From tags/6-36-04@6-36-04
Hello Experts,
In the following snippet, the first print statement (rdf.Display()→Print()) inside helper function __useEnergyFilterAndGetIndices() correctly prints out the desired DataFrame.
Similarly, the last node’s print statement (filtered_in.Display()->Print()) also prints out the desired DataFrame. The node is then returned.
However, outside the helper function, it seems that the RNode filtered_out is empty.
I could not figure out why this is the case.
namespace {
ROOT::RDataFrame hadronicShowerProfiles("Had", "data/AllShowers.root");
ROOT::RDataFrame emShowerProfiles("EM", "data/AllShowers.root");
}
nicemc::RNG myrng;
ROOT::RDF::RNode __useEnergyFilterAndGetIndices(ROOT::RDataFrame rdf, double target_energy){
rdf.Display()->Print();
auto bw_target_and = [&target_energy](float engy){return TMath::Abs(engy - target_energy);};
auto diff_rdf = rdf.Define("difference", bw_target_and, {"energy"});
double min_diff_value = diff_rdf.Min("difference").GetValue();
double TOLERANCE = 1e-20;
auto floating_point_comparison =
[&TOLERANCE, &min_diff_value]
(double each_diff_value)
{return TMath::Abs(each_diff_value - min_diff_value) <= TOLERANCE;};
auto filtered_in = diff_rdf.Filter(floating_point_comparison, {"difference"});
filtered_in.Display()->Print();
return filtered_in;
}
void getShowerProfile(
double targetShowerEnergy, nicemc::ShowerType type, bool force_first_in_bin = false
){
ROOT::RDataFrame rdf(0);
switch(type){
case nicemc::ShowerType::Hadronic:
rdf = hadronicShowerProfiles;
break;
case nicemc::ShowerType::ElectroMagnetic:
rdf = emShowerProfiles;
break;
}
ROOT::RDF::RNode filtered_out = __useEnergyFilterAndGetIndices(rdf, targetShowerEnergy);
filtered_out.Display()->Print();
}
