doc/hackathon/df024__Display_8py.html

import ROOT


# Setting up a Dataframe with some data

ROOT.gInterpreter.ProcessLine('''

   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<int>({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<std::vector<double>>({{z, ++z}, {z, ++z}, {z, ++z}});

              }); // A column of matrices

''')


d = ROOT.d


# Preparing the RResultPtr<RDisplay> object with all columns and default number of entries

d1 = d.Display("")

# Preparing the RResultPtr<RDisplay> object with two columns and default number of entries

cols = ROOT.vector('string')(); cols.push_back("x"); cols.push_back("y");

d2 = d.Display(cols)


# Printing the short representations, the event loop will run

print("The following is the representation of all columns with the default nr of entries")

d1.Print()

print("\n\nThe following is the representation of two columns with the default nr of entries")

d2.Print()