Draw polygons more efficiently with matplotlib

Abstraction: Rendering 60000 geographic polygons efficiently using matplotlib basemap

Key points:

• Naive per-polygon loop adding individual Polygon patches takes ~1.5 minutes for 60,000 shapes
• Each shape has lat/lon corners converted to map x/y via basemap before creating a Polygon patch
• Pattern uses plt.gca().add_patch(poly) in a loop — O(n) patch additions is the bottleneck
• Standard solution is PatchCollection, which batches all polygons into a single artist for rendering
• Float16 ('f2') used for coordinate arrays, which may reduce precision for some projections

Connections: Matplotlib · Data Visualization · Geospatial Visualization

Source: http://stackoverflow.com/questions/12881848/draw-polygons-more-efficiently-with-matplotlib