How to use the wradlib.georef.projection.reproject function in wradlib

Here, the coordinates of the east and west directions won't come to lie on
    the latitude of the site because the beam doesn't travel along the latitude
    circle but along a great circle.

    See :ref:`/notebooks/basics/wradlib_workflow.ipynb#\
Georeferencing-and-Projection`.
    """
    if proj is None:
        proj = projection.get_default_projection()

    xyz, rad = spherical_to_xyz(r, phi, theta, sitecoords, re=re, ke=ke,
                                squeeze=True)

    # reproject aeqd to destination projection
    coords = projection.reproject(xyz, projection_source=rad,
                                  projection_target=proj)

    return coords

"""
    # prepare the range and azimuth array so they describe the boundaries of
    # a bin, not the centroid
    r, phi = _check_polar_coords(r, phi)
    r = np.insert(r, 0, r[0] - _get_range_resolution(r))
    phi = phi - 0.5 * _get_azimuth_resolution(phi)
    phi = np.append(phi, phi[0])
    phi = np.where(phi < 0, phi + 360., phi)

    # generate a grid of polar coordinates of bin corners
    r, phi = np.meshgrid(r, phi)

    coords, rad = spherical_to_xyz(r, phi, theta, sitecoords, squeeze=True,
                                   strict_dims=True)
    if proj is not None:
        coords = projection.reproject(coords, projection_source=rad,
                                      projection_target=proj)

    llc = coords[:-1, :-1]
    ulc = coords[:-1, 1:]
    urc = coords[1:, 1:]
    lrc = coords[1:, :-1]

    vertices = np.stack((llc, ulc, urc, lrc, llc), axis=-2).reshape((-1, 5, 3))

    if proj is None:
        return vertices, rad
    else:
        return vertices

"""
    # make sure the range and azimuth angles have the right properties
    r, phi = _check_polar_coords(r, phi)

    r = r - 0.5 * _get_range_resolution(r)

    # generate a polar grid and convert to lat/lon
    r, phi = np.meshgrid(r, phi)

    coords, rad = spherical_to_xyz(r, phi, theta, sitecoords, squeeze=True)

    if proj is None:
        return coords, rad
    else:
        return projection.reproject(coords, projection_source=rad,
                                    projection_target=proj)

sinlat0 = np.sin(np.radians(lat0))

            fac = (6370.040 ** 2.) * ((1. + sinlat0) ** 2.)
            lon = np.degrees(np.arctan((-x / y))) + lon0
            lat = np.degrees(np.arcsin((fac - (x ** 2. + y ** 2.)) /
                                       (fac + (x ** 2. + y ** 2.))))
            radolan_grid = np.dstack((lon, lat))
        else:
            # create radolan projection osr object
            proj_stereo = projection.create_osr("dwd-radolan")

            # create wgs84 projection osr object
            proj_wgs = projection.get_default_projection()

            radolan_grid = projection.reproject(radolan_grid,
                                                projection_source=proj_stereo,
                                                projection_target=proj_wgs)

    return radolan_grid