USA COVID-19 Cases Map

Here is a quick experiment using the interactive visualization notebooks over at Observable to prototype a map-based data visualization.

This visualization combines several different techniques to implement a choropleth map representing US COVID-19 cases by county.

Individual county statistics are viewable by mousing over each county.

One click will zoom to a state view, and another click will reset to the default view.  Alternatively, the map can be zoomed manually.

The data is sourced dynamically from the GitHub repository maintained by the NY Times.

Implementation code, ideas, and data were found here:

The color scheme itself is kludged using arbitrary thresholds to highlight where things are happening. A linear scale doesn’t work because NYC is such an outlier currently (it washes everything else to white). I tried variations of log scales which didn’t quite work.

I also tried quantile and sequential quantile scales, and while those did allow for differentiated display across all the data, I don’t like how it put counties with ~40 cases in the same bucket as counties with >30k cases.

If anyone has any ideas about that, I’d love to hear from you.

The interactive Observable notebook can be found here: