Richard Vale plots historical battles:
I recently learned about an interesting way of reducing the dimension of a data set. I’d like to illustrate it with a data set of about 550 historical battles in the UK, extracted from Wikidata using a SPARQL query. No doubt some readers will have seen this idea before, but it’s new to me and I found it pretty.
The following plot shows the raw data, with a crossed swords symbol for the location of each battle. It’s possible to see some patterns on the plot (for example, it probably wasn’t much fun to live on the borders of mediaeval Wales) but it could be clearer.
Click through to learn about Hilbert curves and how we can use them to map 2D information to a 1D space. I’d love to see the repro code for this, but Richard does explain the technique. H/T R-Bloggers.