Open clarisma opened 8 months ago
Comparison of Fast (scaled Mercator projection -- current approach) and Accurate (Lambert projection). Difference isn't dramatic. Fast, however, is 5x faster than Accurate.
(Greenland is way off because we're comparing the larger admin area in OSM to the land area stated in Wikipedia).
Area (in square km)
Name Fast Accurate Wikipedia
------------------------- ---------- ---------- ----------
Araucania (Chile) 31869.80 31766.66 31842.30
Baffin Island 519325.54 510095.64 507451.00
Bavaria 70552.73 70354.87 70550.19
Germany (land area) 354626.80 356287.03 357600.00
Greenland (admin area) 2414716.20 2534771.03 2166086.00
Komsomolets Island 8724.11 8821.01 9006.00
Meighen Island 934.37 925.45 955.00
Nordaustlandet 14186.02 14224.67 14443.00
Tarapaca (Chile) 42608.18 42547.26 41799.50
Saarland (Germany) 2570.34 2563.73 2570.00
Sakhalin (Russia) 74632.04 74316.81 72492.00
Victoria Island (Canada) 215938.80 218829.33 217291.00
Victoria Island (Russia) 5.98 5.97 10.80
Currently,
Feature.area
uses a Euclidian algo (scaled to latitude), which suffers from loss of accuracy near the poles. Accuracy would improve by re-projecting coordinates into an equal-area projection, with only a small decrease in speed (?? - see comment below)