July 8, 2022

Placemark thematic maps, v2

This week we're rolling out a big update to Placemark's support for thematic mapping. In this case, that means mostly choropleth maps - in which some number determines the color of an area - and classified maps, which map discrete values to different colors.

We had some thematic mapping features, before, but this update really starts from scratch to make it all way better.

  • We now support both linear and quantile classifications for choropleth maps. This is a big boost for datasets that have outliers: with a linear scale, you'll get almost no color differentiation for most features if there's one feature with a really high or really low relative value.
  • You can now use literal styles - simplestyle - at the same time as data-driven styles. This lets you easily override data-driven styles with your own.
  • There's a new UI for literal styles which makes them way simpler. Now you don't have to remember which properties control literal styles, and there are convenient number & color inputs for each of the parts of a literal style.
  • The color ramps are improved - we're starting with the renowned presets from ColorBrewer, and all of the options available are safe for most forms of colorblindness. You can choose whether to interpolate colors between stops, or treat them like steps.
  • You can export these ramps now, to both Mapbox GL styles (which you can also use with Maplibre) and Leaflet styles.