Multigraph tutorial

In [1]:
from ROOTaaS.iPyROOT import ROOT
ROOT.toCpp()
Welcome to ROOTaas Beta
Notebook is in Cpp mode

The Canvas

To begin with, we must create a canvas on which to put our multigraph (which we will create using the class TMultiGraph).

In [2]:
TCanvas c1("c1","multigraph",700,500);
c1.SetGrid();

TMultiGraph mg("mg","mg");

Graph 1

We then create our first graph.

In [3]:
const Int_t n1 = 10;
Double_t px1[] = {-0.1, 0.05, 0.25, 0.35, 0.5, 0.61,0.7,0.85,0.89,0.95};
Double_t py1[] = {-1,2.9,5.6,7.4,9,9.6,8.7,6.3,4.5,1};
Double_t ex1[] = {.05,.1,.07,.07,.04,.05,.06,.07,.08,.05};
Double_t ey1[] = {.8,.7,.6,.5,.4,.4,.5,.6,.7,.8};
TGraphErrors gr1(n1,px1,py1,ex1,ey1);
gr1.SetMarkerColor(kBlue);
gr1.SetMarkerStyle(21);
mg.Add(&gr1);

Graph 2

We then create our second one.

In [4]:
const Int_t n2 = 10;
Float_t x2[]  = {-0.28, 0.005, 0.19, 0.29, 0.45, 0.56,0.65,0.80,0.90,1.01};
Float_t y2[]  = {2.1,3.86,7,9,10,10.55,9.64,7.26,5.42,2};
Float_t ex2[] = {.04,.12,.08,.06,.05,.04,.07,.06,.08,.04};
Float_t ey2[] = {.6,.8,.7,.4,.3,.3,.4,.5,.6,.7};
TGraphErrors gr2(n2,x2,y2,ex2,ey2);
gr2.SetMarkerColor(kRed);
gr2.SetMarkerStyle(20);
mg.Add(&gr2);

End Product

We add the two graphs onto our canvas, and update it.

In [5]:
mg.Draw("APL");
mg.GetXaxis()->SetTitle("X values");
mg.GetYaxis()->SetTitle("Y values");
In [ ]: