The interactive map below shows the neighborhoods in the municipality of Amsterdam. Clicking on "Visible layers", on the upper-right corner, allows you to toggle on and off the two layers of data: on a scale of yellow to red is the total volume of Foursquare checkins; on purples is the diversity index (fractionalization) used in the regressions. Both choropleths are created using seven quantiles.
You can also zoom in and out and explore each neighborhood. Clicking on a polygon shows you the number of checkins and the value of the diversity index.