// Reads the points from a file and produces a simple graph.
int macro2(){
TCanvas* 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");
// Draw the Legend
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");
graph.Print();
}