unsigned long long y = 1; int x = 1; double w = 1; double z = 1; ROOT::RDataFrame df(10); auto d = df.Define("y", [&y]() { return y *= 100; }) // A column with ulongs .Define("x", [&x]() { return std::vector({x++, x++, x++, x++}); }) // A column with four-elements collection .Define("w", [&w]() { return w *= 1.8; }) // A column with doubles .Define("z", [&z]() { z *= 1.1; return std::vector>({{z, ++z}, {z, ++z}, {z, ++z}}); }); // A column of matrices auto d1 = d.Display(""); auto d2 = d.Display({"x", "y"}); std::cout << "The following is the representation of all columns with the default nr of entries" << std::endl; d1->Print(); std::cout << "\n\nThe following is the representation of two columns with the default nr of entries" << std::endl; d2->Print(); gROOT->GetListOfCanvases()->Draw()