Details
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Bug
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Resolution: Fixed
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High
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6.14/04
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None
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all
Description
Dave H. reports on the forum that it is not possible to work with ROOT datasets which contain columns holding pointers to `TVector3`. This causes a crash, also when such columns are not involved in the actions/transformations (see https://root-forum.cern.ch/t/how-can-i-create-an-rdataframe-from-a-ttree-containing-a-branch-of-type-tbranchobject/31144/6).
This is the reproducer:
// This script produces the following output:
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//
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// root [0]
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// Processing example_tbranchobject_problem.C...
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// a is a TBranchElement
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// b is a TBranchElement
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// c is a TBranchObject
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// terminate called after throwing an instance of 'std::runtime_error'
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// what(): GetBranchNames: unsupported branch type
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#include "TFile.h"
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#include "TTree.h"
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#include "ROOT/RDataFrame.hxx"
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void createtree() {
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TFile tfile("examplefile.root", "RECREATE");
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TTree tree("tree", "tree");
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auto a = TVector3();
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auto b = TVector3();
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auto c = new TVector3();
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tree.Branch("a", &a);
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tree.Branch("b", &b);
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tree.Branch("c", "TVector3", &c, 32000, 0); // This method of creating a branch creates a branch of type "TBranchObject". If this line is commented out the script runs as expected.
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for (int ii = 0; ii < 10; ++ii) {
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a.SetX(ii);
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b.SetX(2*ii);
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c->SetX(3*ii);
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tree.Fill();
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}
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tree.Write();
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tfile.Close();
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return;
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}
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void checktype() {
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TFile tfile("examplefile.root", "READ");
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auto tree = (TTree*)tfile.Get("tree");
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for (auto br : *tree->GetListOfBranches()) {
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std::cout << br->GetName() << " is a " << br->IsA()->GetName() << std::endl;
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}
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}
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void readtree() {
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ROOT::RDataFrame rdf("tree", "examplefile.root");
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auto ha = rdf.Define("aval", "a.X()").Histo1D("aval");
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auto hb = rdf.Define("bval", "b.X()").Histo1D("bval");
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auto hc = rdf.Define("cval", "c.X()").Histo1D("cval");
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std::cout << "mu(a):" << ha->GetMean() << std::endl;
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std::cout << "mu(b):" << hb->GetMean() << std::endl;
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std::cout << "mu(c):" << hc->GetMean() << std::endl;
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}
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void example_tbranchobject_problem() {
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createtree();
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checktype();
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readtree();
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return;
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}
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