Санкт-Петербург - ERA proxy heatmap
Shading = intra-city percentile (relative!).
Absolute raw density (weighted, log1p-damped, competition subtracts):
max = 18.93, median = 0.00, cells > 0: 2279/8597
A weak city stays weak in absolute terms even if its percentiles look hot. Canonical deliverable: grid_map.html. Шкала процентилей относительна внутри города; абсолютные значения выше.