Takes cropped cities and counts the number of grid cells which are classified as "urban area".
measure_cities(topn = 100, overwrite = FALSE, cutoff = 30, w = 9, h = 6)integer how many cities to consider. default: 100.
TRUE/FALSE
numeric indicating the cutoff value (percent) of built-up area above which we classify as "urban"
We read the list of cropped city bounding boxes from cropboxes in order to classify them as either urban area or not.
The classification of urban or not is governed by two constraints:
the cutoff parameter. If a grid cell is measured with built-up surface of more than cutoff, the cell is retained as urban.
Contiguity of grid cells. Given that classified grid cells could be separated in space, we check for the largest connect set. The check uses the "rook move" as criterion.
As a second