Map Clustering Is Not My Favorite

Map Clustering Is Not My Favorite(blog.greg.technology)

18 points by gregsadetsky 4 days ago | 9 comments

I have an app that is heavily map-based. It's an iOS app that uses Apple Maps (I know, I know, controversy, yadda, yadda; but there's a good reason -many of them, in fact- that I use Apple Maps).

I found that the built-in AM clustering truly sucks, so I wrote my own. It's not perfect, but delivers a much better experience than the native one.

mkj 43 minutes ago |

There are excellent examples of the problem in Edward Tufte's "Envisioning Information". Have a look at http://blah.ksteinfe.com/181106/tufte_envisioning_informatio... for a few snippets of it, then buy the book.

well_ackshually 2 minutes ago |

>You don’t have to cluster anymore. You can just be.

Try to get Google Maps or Apple Maps running on a phone with more than 200 Markers/Annotations, then come back to me with that. Their performance is fucking dreadful. Google Maps released a new renderer that just OOMs if you're rendering a Polyline with 5k segments. Decimate it or face consequences.

As far as I know, MapBox is about the only one that has tolerable performance. Anyone else doing heavy work and using the gmaps SDK is figuring out tricks: overlay rendering (drawing on a canvas above the map, which requires expensive RPC calls to get visible bounds / map projection which makes performance shit if you're not careful and always lags a frame behind), intense caching of marker descriptors, careful management of markers (dropping 200 Markers from scrolling the map + adding 200? Enjoy your main thread work that freezes the map), etc, etc.

First party map tools are absolute dog shit.

phillipseamore 4 days ago |

Clustering is only asked for by someone that has no interest in or understanding of the data.

paganel 1 hour ago | |

It does save a purpose. For example in the OP's non-clustering example all of the Britain is covered in dots, I'm talking at the highest zoom level, while the Atlas Obscura version, the one that uses clustering, does a better job of providing data by mentioning how many points that general area contains.

jamessb 43 minutes ago | | |

In such cases I generally prefer displaying counts of points in defined areas, rather than using clustering (e.g., when zoomed out, show counts per country, and when zoomed in more show counts for states or equivalent sub-national areas).

mkj 41 minutes ago | | |

If you have less than hundreds of thousands of points, you can probably get away with drawing individual dots on the map. Computer screens are high res.

RicoElectrico 25 minutes ago | | |

Then, the dots should be less than 100% opacity, which helps convey density wherever they overlap. It's feasible in overpass turbo with its rather simplistic MapCSS, so it should be possible in proper web mapping libraries.