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pacificclimate / weather-anomaly-tool

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Aggregate circle markers at low zoom levels #9

Open rod-glover opened 6 years ago

rod-glover commented 6 years ago

Question: If dots are coloured to show value, how should aggregated circles be coloured? Averaging suggests itself, but naively applied it could be misleading.

rod-glover commented 6 years ago

See https://github.com/Leaflet/Leaflet.markercluster

rod-glover commented 6 years ago

For aggregate markers, show average value of aggregated station.

There is an issue with aggregating over large areas -- contributing stations will not be properly weighted for the area they represent. At higher zoom levels, averaging over stations is OK because the clustering algorithm tends to make each contributing station responsible for an approximately equal area. Therefore it is approximately area-weighted and therefore sufficiently correct.

We may want to limit the degree of aggregation, i.e., cut out below a certain zoom level, so that users do not make the erroneous conclusion that the single aggregated marker represents a correct average value for the entire province.

We may want to add a caveat statement on the UI about the limitations and correctness aggregated values.

rod-glover commented 3 months ago

Is this actually useful? It sounds complicated and potentially misleading without delivering much value.