# Df 0 2 4_ Display¶

This tutorial shows how to use the Display action

Author: Enrico Guiraud, Danilo Piparo, Enric Tejedor Saavedra CERN, Massimo Tumolo Politecnico di Torino
This notebook tutorial was automatically generated with ROOTBOOK-izer from the macro found in the ROOT repository on Saturday, January 18, 2020 at 01:41 AM.

Setting up a dataframe with some data

In :
unsigned long long y = 1;
int x = 1;
double w = 1;
double z = 1;
ROOT::RDataFrame tdf(10);
auto d = tdf.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


Preparing the rresultptr object with all columns and default number of entries

In :
auto d1 = d.Display("");


Preparing the rresultptr object with two columns and default number of entries

In :
auto d2 = d.Display({"x", "y"});


Printing the short representations, the event loop will run

In :
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();

The following is the representation of all columns with the default nr of entries
y           | x   | w         | z                        |
100         | 1   | 1.8000000 | { 1.1000000, 2.1000000 } |
| ... |           | ...                      |
| 4   |           | { 3.1000000, 4.1000000 } |
10000       | 5   | 3.2400000 | { 4.5100000, 5.5100000 } |
| ... |           | ...                      |
| 8   |           | { 6.5100000, 7.5100000 } |
1000000     | 9   | 5.8320000 | { 8.2610000, 9.2610000 } |
| ... |           | ...                      |
| 12  |           | { 10.261000, 11.261000 } |
100000000   | 13  | 10.497600 | { 12.387100, 13.387100 } |
| ... |           | ...                      |
| 16  |           | { 14.387100, 15.387100 } |
10000000000 | 17  | 18.895680 | { 16.925810, 17.925810 } |
| ... |           | ...                      |
| 20  |           | { 18.925810, 19.925810 } |

The following is the representation of two columns with the default nr of entries
x   | y           |
1   | 100         |
... |             |
4   |             |
5   | 10000       |
... |             |
8   |             |
9   | 1000000     |
... |             |
12  |             |
13  | 100000000   |
... |             |
16  |             |
17  | 10000000000 |
... |             |
20  |             |


Draw all canvases

In :
gROOT->GetListOfCanvases()->Draw()