NighttimeLights.load_shapefile
— MethodPolygon boundaries are usually stored in a format called shapefile. For example, the shapefile of the world will consist of country names and each country will have coordinates of the boundaries.
load_shapefile("assets/mumbai_map/mumbai_districts.shp")
| | geometry | DISTRICT | ST_NM | ST_CEN_CD | DT_CEN_CD | censuscode |
|:-:|:-------------------:|:---------------:|:-----------:|:---------:|:---------:|:----------:|
| 1 | Polygon(78 Points) | Mumbai | Maharashtra | 27 | 23 | 519 |
| 2 | Polygon(139 Points) | Mumbai Suburban | Maharashtra | 27 | 22 | 518 |
Each row of a shapefile dataframe contains a polygon and other information about it.
NighttimeLights.polygon_mask
— MethodThe polygon of a shapefile row can be make into a mask. This means all the points inside the polygon will be marked as 1, while the points outside will be marked as 0.
mumbai_districts = load_shapefile("assets/mumbai_map/mumbai_districts.shp")
district1 = mumbai_dists[1,:] # Select the first district
district1_mask = polygon_mask(my_coordinate_system, district1)
Once a mask is obtained from a polygon, the mask can be used as just as any other mask.