square bbox

bbox.py

from pyproj import Transformer
import geojson

to_metric = Transformer.from_crs(4326, 3857)
to_latlon = Transformer.from_crs(3857, 4326)

def square(lon:float, lat:float, dim:float, unit:str='area'):
    """ """
    
    if unit == 'area':
        length = (dim**.5)/2
    else:
        length = dim/2

    xc, yc = to_metric.transform(lon, lat)

    x_min = xc - length
    x_max = xc + length
    y_min = yc - length
    y_max = yc + length
    
    lon_min, lat_min = to_latlon.transform(x_min, y_min)
    lon_max, lat_max = to_latlon.transform(x_max, y_max)
    
    feature = geojson.Feature(
        properties = {},
        geometry = geojson.Polygon([[
            (lon_min, lat_min,),
            (lon_max, lat_min,),
            (lon_max, lat_max,),
            (lon_min, lat_max,),
            (lon_min, lat_min,),
        ]])
    )
    
    return feature

if __name__ == '__main__':
    
    feature = square(0, 0, 100)
    
    print(feature)