4 posts
Make a kernel density heatmap from points in Python: compare Scott/Silverman, likelihood cross-validation and a fixed planning distance, Gaussian and Epanechnikov kernels and sample weights, export an edge-corrected GeoTIFF with rasterio, show it on a basemap, and map case-control relative risk on Camden's London plane trees.
Test whether points are clustered with point pattern analysis in Python: a quadrat chi-squared test, the Clark-Evans nearest-neighbour index and Ripley's G, F, K and L functions with Monte Carlo CSR envelopes, edge correction, a global MAD test and a random-labelling null, on 3,292 London plane trees in Camden.
A practical guide to Uber's H3 hexagonal grid in Python with the h3-py v4 API: index points, choose a resolution, fill polygons, count 541,081 Overture places across London, smooth with k-rings, do the same in DuckDB's h3 extension, and compare hexagons with square grids of equal area.
Calculate land surface temperature from Landsat 8 and 9 Collection 2 Level-2 data in Python: ST_B10 scale and offset, QA_PIXEL cloud masking, LST by land cover and NDVI, an urban-rural transect, hotspots with OpenStreetMap and an honest comparison with air temperature, for London in the July 2022 heatwave.