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.

Very interesting! I will definitely show this demo to my students when teaching decomposition. Thank you Nikos.

Thank you Foti, I will be putting a couple more demos online, as I try to pair one with each of my lectures.