Search points of interest by radius with Mapbox GL JS by Zach Beattie.
From the post:
Mapbox GL JS provides new and interesting ways to query data found on a map. We built an example that filters points of interest by genre, which uses the
featuresAtmethod to only select data based on the position and radius of the circle. Drag the blue circle around the map to populate points of interest on the left. Zoom in and out on the circle to adjust the radius.
…
Visually, places of interest appear as colored dots on the map and you can select what type of places appear at all. You use the blue circle to move about the map and as it encompasses dots on the map, additional information appears to the left of the map.
That’s a poor description when compared to the experience. Visit the live map to really appreciate it.
Assuming a map of surveillance cameras and the movement of authorities (in near real time), this would make a handy planning tool.