Estimating an MA Model
You will estimate the MA(1) parameter, \(\small \theta\), of one of the simulated series that you generated in the earlier exercise. Since the parameters are known for a simulated series, it is a good way to understand the estimation routines before applying it to real data.
For simulated_data_1
with a true \(\small \theta\) of -0.9, you will print out the estimate of \(\small \theta\). In addition, you will also print out the entire output that is produced when you fit a time series, so you can get an idea of what other tests and summary statistics are available in statsmodels.
This exercise is part of the course
Time Series Analysis in Python
Exercise instructions
- Import the class
ARIMA
in the modulestatsmodels.tsa.arima.model
. - Create an instance of the
ARIMA
class calledmod
using the simulated datasimulated_data_1
and the order (p,d,q) of the model (in this case, for an MA(1)), isorder=(0,0,1)
. - Fit the model
mod
using the method.fit()
and save it in a results object calledres
. - Print out the entire summary of results using the
.summary()
method. - Just print out an estimate of the theta parameter using the
.params[1]
attribute.
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
# Import the ARIMA module from statsmodels
from statsmodels.tsa.arima.model import ARIMA
# Fit an MA(1) model to the first simulated data
mod = ARIMA(___, order=___)
res = mod.___
# Print out summary information on the fit
print(res.___)
# Print out the estimate for the constant and for theta
print("When the true theta=-0.9, the estimate of theta is:")
print(res.___)