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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def mk_dx_dy_from_geotif_layer(geotif):
 """ Extracts the change in x and y coordinates from the geotiff file. Presently only supports WGS-84 files. """

    ELLIPSOID_MAP = {'WGS84': 'WGS-84'}
    ellipsoid = ELLIPSOID_MAP[geotif.grid_coordinates.wkt]
    d = distance(ellipsoid=ellipsoid)
    dx = geotif.grid_coordinates.x_axis
    dy = geotif.grid_coordinates.y_axis
    dX = np.zeros((dy.shape[0]-1))
    for j in xrange(len(dX)):
        dX[j] = d.measure((dy[j+1], dx[1]), (dy[j+1], dx[0])) * 1000  # km2m
    dY = np.zeros((dy.shape[0]-1))
    for i in xrange(len(dY)):
        dY[i] = d.measure((dy[i], 0), (dy[i+1], 0)) * 1000  # km2m
    return dX, dY