Python版本的谷歌S2空间索引算法，索引的算法,参考https://

Python版本的谷歌S2空间索引算法，索引的算法,参考https://

参考https://en.wikipedia.org/wiki/Hilbert_curve

hilbert_map = {    ‘a‘: {(0, 0): (0, ‘d‘), (0, 1): (1, ‘a‘), (1, 0): (3, ‘b‘), (1, 1): (2, ‘a‘)},    ‘b‘: {(0, 0): (2, ‘b‘), (0, 1): (1, ‘b‘), (1, 0): (3, ‘a‘), (1, 1): (0, ‘c‘)},    ‘c‘: {(0, 0): (2, ‘c‘), (0, 1): (3, ‘d‘), (1, 0): (1, ‘c‘), (1, 1): (0, ‘b‘)},    ‘d‘: {(0, 0): (0, ‘a‘), (0, 1): (3, ‘c‘), (1, 0): (1, ‘d‘), (1, 1): (2, ‘d‘)},}un_hilbert_map = {    ‘a‘: { 0: (0, 0,‘d‘), 1: (0, 1,‘a‘), 3: (1, 0,‘b‘),  2: (1, 1,‘a‘)},    ‘b‘: { 2: (0, 0,‘b‘), 1: (0, 1,‘b‘), 3: (1, 0,‘a‘),  0: (1, 1,‘c‘)},    ‘c‘: { 2: (0, 0,‘c‘), 3: (0, 1,‘d‘), 1: (1, 0,‘c‘),  0: (1, 1,‘b‘)},    ‘d‘: { 0: (0, 0,‘a‘), 3: (0, 1,‘c‘), 1: (1, 0,‘d‘),  2: (1, 1,‘d‘)}}#编码def point_to_hilbert(lng,lat, order=16):    print (‘hilbert‘)    lng_range = [-180.0, 180.0]    lat_range = [-90.0, 90.0]    current_square = ‘a‘    position = 0    for i in range(order - 1, -1, -1):        position <<= 2        lng_mid = (lng_range[0]+lng_range[1])/2        lat_mid = (lat_range[0]+lat_range[1])/2        if lng >= lng_mid :            quad_x = 1            lng_range[0] = lng_mid        else:            quad_x = 0            lng_range[1] = lng_mid        if lat >= lat_mid :            quad_y = 1            lat_range[0] = lat_mid        else:            quad_y = 0            lat_range[1] = lat_mid        quad_position,current_square = hilbert_map[current_square][(quad_x, quad_y)]        position |= quad_position    return position#解码def hilbert_to_point( d , order=16):    print (‘hilbert‘)    lng_range = [-180.0, 180.0]    lat_range = [-90.0, 90.0]    current_square = ‘a‘    lng=lat=lng_mid=lat_mid=0    for i in range(order - 1, -1, -1):        lng_mid = ( lng_range[0] + lng_range[1] ) / 2        lat_mid = ( lat_range[0] + lat_range[1] ) / 2        mask = 3 << (2*i)        quad_position = (d & mask) >> (2*i)        quad_x, quad_y, current_square= un_hilbert_map[current_square][quad_position]        if quad_x:            lng_range[0] = lng_mid        else:            lng_range[1] = lng_mid        if quad_y:            lat_range[0] = lat_mid        else:            lat_range[1] = lat_mid    lat = lat_range[0]    lng = lng_range[0]    return lng,latif __name__ == ‘__main__‘:    d = point_to_hilbert(-50.555443,77.776655,36)    print (d)    lng,lat = hilbert_to_point(d,36)    print (lng,lat)

Python版本的谷歌S2空间索引算法