#!/usr/bin/env python
# coding: utf-8

# # Create, draw and fit a 2DGraphErrors
# Ported to Notebook by: Theis Hansaen

# In[1]:


from ROOTaaS.iPyROOT import ROOT 
ROOT.toCpp()


# ### Build, fIt and draw a 2D graph
# To start off we set the style and palette of the graph.

# In[2]:


gStyle->SetPalette(kBird);
double e = 0.3;
int nd = 500;


# Here we are starting to fill our Graph with a function, and we use the TF2 Type because we want our function to be bidimensional.

# In[3]:


TRandom3 my_random_generator;
TF2 f2("f2","1000*(([0]*sin(x)/x)*([1]*sin(y)/y))+200",-6,6,-6,6);
f2.SetParameters(1,1);
TGraph2DErrors dte(nd);


# We use TRandom3 (seen above) to generate random numbers in [-e,e]

# In[4]:


double rnd, x, y, z, ex, ey, ez;
for (Int_t i=0; i<nd; i++){
    f2.GetRandom2(x,y);
    rnd = my_random_generator.Uniform(-e,e);
    z = f2.Eval(x,y)*(1+rnd);
    dte.SetPoint(i,x,y,z);
    ex = 0.05*my_random_generator.Uniform();
    ey = 0.05*my_random_generator.Uniform();
    ez = fabs(z*rnd);
    dte.SetPointError(i,ex,ey,ez);
}


# We set the function's parameters to set the initial values for the fit with the graph. We also make our function more visualy attractive by setting the line to fit our preferences.

# In[5]:


f2.SetParameters(0.7,1.5);
f2.SetTitle("Fitted 2D Function");
f2.SetLineWidth(1);
f2.SetLineColor(kBlue-5);
dte.Fit(&f2);


# We then set the axes, and plot the result of our function.

# In[6]:


TCanvas c;
f2.DrawClone("Surf1");
auto Xaxis = f2.GetXaxis();
auto Yaxis = f2.GetYaxis();
auto Zaxis = f2.GetZaxis();
Xaxis->SetTitle("X Title"); Xaxis->SetTitleOffset(1.5);
Yaxis->SetTitle("Y Title"); Yaxis->SetTitleOffset(1.5);
Zaxis->SetTitle("Y Title"); Zaxis->SetTitleOffset(1.5);
dte.Draw("PO Same");


# To finish off, we make the x and y projections on a new canvas using the command new with the Type TCanvas.

# In[7]:


TCanvas c_p("ProjCan","The Projections",1000,400);
c_p.Divide(2,1);
c_p.cd(1);
dte.Project("x")->Draw();
c_p.cd(2);
dte.Project("y")->Draw();


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