Partial autocorrelation in time series data
Like autocorrelation, the partial autocorrelation function (PACF) measures the correlation coefficient between a time-series and lagged versions of itself. However, it extends upon this idea by also removing the effect of previous time points. For example, a partial autocorrelation function of order 3 returns the correlation between our time series (t_1, t_2, t_3, …) and its own values lagged by 3 time points (t_4, t_5, t_6, …), but only after removing all effects attributable to lags 1 and 2.
The plot_pacf() function in the statsmodels library can be used to measure and plot the partial autocorrelation of a time series.
This exercise is part of the course
Visualizing Time Series Data in Python
Exercise instructions
- Import
tsaplotsfromstatsmodels.graphics. - Use the
plot_pacf()function fromtsaplotsto plot the partial autocorrelation of the'co2'column inco2_levels. - Specify a maximum lag of 24.
Hands-on interactive exercise
Have a go at this exercise by completing this sample code.
# Import required libraries
import matplotlib.pyplot as plt
plt.style.use('fivethirtyeight')
____
# Display the partial autocorrelation plot of your time series
fig = ____(co2_levels[____], lags=____)
# Show plot
plt.show()