Faster polygon construction using Shapely 2.0.0 #47
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Shapely 2.0.0 gains the `shapely.polygons` function which can create a large number of polygons at speed. This is perfect for making dataset geometries.
Changes to Shapely 2.0.0 mean the arguments to `shapely.geometry.box` can no longer be `decimal.Decimal`. They must be numpy-compatible scalar number types.
This interface is drastically quicker than constructing polygons one-by-one. This has reduced the time taken to construct the `gbr4` polygons from ~6 seconds to ~0.1 seconds. Similar reductions apply to other datasets also.
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Shapely 2 exposes a
shapely.polygonsfunction which can create large numbers of polygons directly from numpy arrays. This gives a dramatic performance improvement, varying by dataset type. For UGRID I have seen the time taken to construct the polygons halve, for large CF grids the time has dropped from ~6 seconds to ~0.1 second.This makes #40 irrelevant. This was found when investigating caching strategies. The slow down was always in constructing the polygons not in calculating vertices, and polygons still have to be constructed when loading them from the cache.