Hi, is there a way to take the max and the min X value from a Tgraph?

I’ve a TTree and i need the range xmax-xmin of the graph i have from the ttree.

For a tree:

TTree::GetMinimum

TTree::GetMaximum

For a “`graph`

”:

`TMath::MinElement(graph->GetN(), graph->GetX())`

`TMath::MaxElement(graph->GetN(), graph->GetX())`

It might be overall fewer lines with RDataFrame. To just get the min/max of a column, maybe conditional to a cut, these are all the lines you need:

```
auto selected_df = ROOT::RDataFrame("treename", "filename.root").Filter("x > 0");
auto min = df.Min("x");
auto max = df.Max("y");
```

To create a TGraph from an RDataFrame:

```
ROOT::RDataFrame df("treename", "files/*.root");
graph = df.Graph("x", "y");
```

Cheers,

Enrico

it says error: no member named ‘MaxElement’ in ‘TGraph’

i don’t understand the value i have in output on the terminal.

oh sorry, all is correct! i was wrong with copy/paste…