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

# # Filling a n-tuple (simulating the conductivity of a material in different conditions of pressure and temperature) and writing it to a file
# Ported to Notebook by: Theis Hansen
# 
# To use the ROOT toolkit, we need to import ROOT onto our Notebook, which we also set to C++

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from ROOTaaS.iPyROOT import ROOT
ROOT.toCpp()


# ### The Tuple
# We create a file which will contain our ntuple and the tuple itself.

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TFile ofile("conductivity_experiment.root","RECREATE");
TNtuple cond_data("cond_data","Example N-Tuple","Potential:Current:Temperature:Pressure");


# Then we fill it randomly (to simulate acquired data) using the TRandom3 random generator.
# We are also applying some "smearing" (measurement errors): 1% error on voltage (pot), pressure and current and 1.3 absolute error on temperature.
# At the end of the loop body we fill the ntuple.

# In[3]:


TRandom3 rndm;
float pot,cur,temp,pres;
for (int i=0;i<10000;++i){
    pot=rndm.Uniform(0.,10.);
    temp=rndm.Uniform(250.,350.);
    pres=rndm.Uniform(0.5,1.5);
    cur=pot/(10.+0.05*(temp-300.)-0.2*(pres-1));
    
    pot*=rndm.Gaus(1.,0.01);
    temp+=rndm.Gaus(0.,0.3);
    pres*=rndm.Gaus(1.,0.02);
    cur*=rndm.Gaus(1.,0.01);    
    
    cond_data.Fill(pot,cur,temp,pres);
}


# Save the TNtuple and close the file.

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cond_data.Write();
ofile.Close();


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