In [2]:

```
from ROOTaaS.iPyROOT import ROOT
ROOT.toCpp()
```

Let's inspect the input file, which is in the appropriate format for filling a TGraphErrors

In [3]:

```
.! cat macro2_input.txt
```

Now, let's start with the creation of the graphs as well as some beautification

In [4]:

```
auto c=new TCanvas();c->SetGrid();
TGraphErrors graph_expected("./macro2_input_expected.txt","%lg %lg %lg");
graph_expected.SetTitle("Measurement XYZ and Expectation;lenght [cm];Arb.Units");
graph_expected.SetFillColor(kYellow);
graph_expected.DrawClone("E3AL"); // E3 draws the band
TGraphErrors graph("./macro2_input.txt","%lg %lg %lg");
graph.SetMarkerStyle(kCircle);
graph.SetFillColor(0);
graph.DrawClone("PESame");
```

We add a legend to improve the clarity of the plot. It is always reccomended to make the plot "self descriptive".

In [5]:

```
TLegend leg(.1,.7,.3,.9,"Lab. Lesson 2");
leg.SetFillColor(0);
leg.AddEntry(&graph_expected,"Expected Points");
leg.AddEntry(&graph,"Measured Points");
leg.DrawClone("Same");
```

In [ ]:

```
```