#this method takes the output from ODEint (SOL), and the list of
#times that ODEint was evaluated at (t), and returns a dataframe
#that contains theta (with periodic boundtry conditions), omega,
#and time
def constructDataFrame(SOL,t):
df = pd.DataFrame(-SOL, columns = ["theta","omega"])
df["time"]= t
df["Ptheta"]=np.remainder(df["theta"]+np.pi,2*np.pi)-np.pi
return df