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Rebuilding Strava's Global Heatmap

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Re: Rebuilding Strava's Global Heatmap

#12

This is lovely. One question - did you consider a vector style versus a raster style? If so, why did you choose raster?

I think there are two parts:

1) Internal representation for building/serving: For vector, the data would have to be aggregated in some way otherwise it would be way too slow (for example, tiles having 10 million or more lines). How exactly to do that vector aggregation is a real challenge. If there is a good solution I'm not aware of it.

2) End product quality: everything is ultimately rasterized on the viewer's monitor. So if upstream resolution is high enough vector doesn't have any advantage here.

Re: Rebuilding Strava's Global Heatmap

#14
This is beautiful. Thanks so much for creating it. I’m hoping you can explain what looks like an anomaly though. Looking at Macritchie Reservoir in Singapore, there’s the expected hot outline on parts of its shore, but also a dead-straight oblong running roughly east-West for over 1km. Thing is, it can’t be a running track as it’s in the middle of the reservoir itself. Any thoughts on how this artefact got there?

Re: Rebuilding Strava's Global Heatmap

#15

This is beautiful. Thanks so much for creating it. I’m hoping you can explain what looks like an anomaly though. Looking at Macritchie Reservoir in Singapore, there’s the expected hot outline on parts of its shore, but also a dead-straight oblong running roughly east-West for over 1km. Thing is, it can’t be a running track as it’s in the middle of the reservoir itself. Any thoughts on how this artefact got there?

I think that is some kind of rowing/swimming/boating course. It shows up in the running layer because a few people mislabel their activity types. It shows up much stronger in the water layer. Next update to the heatmap I intend to add a activity type classifier to help with these errors.
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