I made this little interactive demo for basic time series exploration and decomposition for my students. I uploaded it here in case someone else finds it useful. Some things to try:
- How does the seasonal plot looks like for seasonal and non-seasonal time series?
- How does the seasonal plot looks when the trend is not removed?
- How does the time series decomposition looks like when additive or multiplicative form is applied wrongly?
- What is the effect of different seasonality estimations when decomposing?
Different types of seasonal plots are implemented as well. I find that sometimes looking at alternative forms is quite helpful.