Returns coordinates of a polygon object for a center point and radius.

buffer_geometry.py

from functools import (
    partial
)
import pyproj
from shapely.geometry import (
    Point, 
    Polygon
)
from shapely.ops import (
    transform
)

def buffer(
    longitude, 
    latitude,
    radius
):

    """
    Returns coordinates of a polygon object for a center point and radius.

    Parameters
    ----------
    longitude: the longitude expressed as a positive or negative double value.
    latitude: the latitude expressed as a positive or negative double value.
    radius: the distance in meters from the center point.

    Returns
    -------
    polygon: shapely.geometry.polygon.Polygon
    """

    # Sets the azimuthal equidistant projection using latitude, longitude coordinates.
    azimuthal_projection = f"+proj=aeqd +R=6371000 +units=m +lat_0={latitude} +lon_0={longitude}"

    # Transform the azimuthal equidistant projection from WGS84 to AEQD.
    wgs84_to_aeqd = partial(
        pyproj.transform,
        pyproj.Proj(
            "+proj=longlat +datum=WGS84 +no_defs"
        ),
        pyproj.Proj(
            azimuthal_projection
        ),
    )

    # Transform the azimuthal equidistant projection from AEQD to WGS84.
    aeqd_to_wgs84 = partial(
        pyproj.transform,
        pyproj.Proj(
            azimuthal_projection
        ),
        pyproj.Proj(
            "+proj=longlat +datum=WGS84 +no_defs"
        ),
    )

    # Specifies the center point of the buffer using the longitude, latitude coordinates.
    center = Point(
        float(
            longitude
        ), 
        float(
            latitude
        )
    )

    # Transforms the center point of the buffer using AEQD azimuthal equidistant projection.
    point = transform(
        wgs84_to_aeqd, 
        center
    )

    # Specifies the radius and computes a polygon that represents all points of the buffer.
    point_buffer = point.buffer(
        radius
    )

    # Transforms the polygon to WGS84 azimuthal equidistant projection. 
    polygon = transform(
        aeqd_to_wgs84, 
        point_buffer
    )

    # Returns the coordinates of the polygon geometry.
    return (
        polygon
    )

requirements.txt

pyproj>=3.0.1
shapely>=1.8.1