def barotropic_eqlat_lwa(ylat, vort, area, dmu, n_points, planet_radius=
    6378000.0):
    """
    Compute equivalent latitude and wave activity on a barotropic sphere.

    Parameters
    ----------
    ylat : sequence or array_like
        1-d numpy array of latitude (in degree) with equal spacing in ascending order; dimension = nlat.
    vort : ndarray
        2-d numpy array of vorticity values; dimension = (nlat, nlon).
    area : ndarray
        2-d numpy array specifying differential areal element of each grid point; dimension = (nlat, nlon).
    dmu: sequence or array_like
        1-d numpy array of latitudinal differential length element (e.g. dmu = cos(lat) d(lat)). Size = nlat.
    n_points : int, default None
        Analysis resolution to calculate equivalent latitude. If input as None, it will be initialized as *nlat*.
    planet_radius : float, default 6.378e+6
        radius of spherical planet of interest consistent with input 'area'.

    Returns
    -------
    qref : ndarray
        1-d numpy array of value Q(y) where latitude y is given by ylat; dimension = (nlat).
    lwa_result : ndarray
        2-d numpy array of local wave activity values;
                    dimension = [nlat_s x nlon]
    """
    from hn2016_falwa import basis
    nlat = vort.shape[0]
    nlon = vort.shape[1]
    if n_points is None:
        n_points = nlat
    qref, dummy = basis.eqvlat(ylat, vort, area, n_points, planet_radius=
        planet_radius)
    lwa_result, dummy = basis.lwa(nlon, nlat, vort, qref, dmu)
    return qref, lwa_result
