Lest anyone think I’m making up the Greek letters.
And to be fair, sometimes you also see λ. That’s great because λ is equivalent to l, so it stands for the one of longitude and latitude that starts with l.
Okay, fine, @jonty cajoled me into it. Lighter is more traffic; warmer is more positive anomaly for the day.
Now, certain nerds and haters might squint at this and say “It looks like you did this in oklab color space and then tried to half-ass some gamut mapping when you remembered that a lot of the highest z scores are in places with very low traffic counts!” and I would rebut that in scrupulous detail with one simple argument: Good night.
Same general idea and source data, but this time it’s just z-score (https://en.wikipedia.org/wiki/Standard_score), with red positive and green negative. Hard to say that this makes it easier to spot the interesting anomalies, but it seemed like the common sense thing to try. You can see the the OceanGate incident, the earthquake in Turkey and Syria, probably some festivals, etc.
You know him on the internet. Eucalypt-adjacent; very occasional writer. Consulting and passively looking for work in geospatial, image processing, and related fields.