How to use the quantecon.tests.write_array function in quantecon

def _new_solutions(cp, f, grp, which="both"):
    v_init, c_init = cp.initialize()
    if which == "both":

        v_vfi, c_vfi = _solve_via_vfi(cp, v_init, return_both=True)
        c_pfi = _solve_via_pfi(cp, c_init)

        # Store solutions in chunked arrays...
        write_array(f, grp, c_vfi, "c_vfi")
        write_array(f, grp, v_vfi, "v_vfi")
        write_array(f, grp, c_pfi, "c_pfi")

        return v_vfi, c_vfi, c_pfi

    elif which == "vfi":
        v_vfi, c_vfi = _solve_via_vfi(cp, v_init, return_both=True)
        write_array(f, grp, c_vfi, "c_vfi")
        write_array(f, grp, v_vfi, "v_vfi")

        return v_vfi, c_vfi

    elif which == "pfi":
        c_pfi = _solve_via_pfi(cp, c_init)
        write_array(f, grp, c_pfi, "c_pfi")

phi_vfi = sp.get_greedy(v)

    # also run v through bellman so I can test if it is a fixed point
    # bellman_operator takes a long time, so store result instead of compute
    new_v = sp.bellman_operator(v)

    # compute policy rule using pfi

    phi_init = np.ones(len(sp.pi_grid))
    phi_pfi = compute_fixed_point(sp.res_wage_operator, phi_init,
                                  error_tol=_tol, max_iter=5000)

    # write all arrays to file
    write_array(f, grp, v, "v")
    write_array(f, grp, phi_vfi, "phi_vfi")
    write_array(f, grp, phi_pfi, "phi_pfi")
    write_array(f, grp, new_v, "new_v")

    # return data
    return v, phi_vfi, phi_pfi, new_v

def _new_solution(jv, f, grp):
    "gets new solution and updates data file"
    V = _solve_via_vfi(jv)
    write_array(f, grp, V, v_nm)

    return V

# also run v through bellman so I can test if it is a fixed point
    # bellman_operator takes a long time, so store result instead of compute
    new_v = sp.bellman_operator(v)

    # compute policy rule using pfi

    phi_init = np.ones(len(sp.pi_grid))
    phi_pfi = compute_fixed_point(sp.res_wage_operator, phi_init,
                                  error_tol=_tol, max_iter=5000)

    # write all arrays to file
    write_array(f, grp, v, "v")
    write_array(f, grp, phi_vfi, "phi_vfi")
    write_array(f, grp, phi_pfi, "phi_pfi")
    write_array(f, grp, new_v, "new_v")

    # return data
    return v, phi_vfi, phi_pfi, new_v

def _new_solutions(cp, f, grp, which="both"):
    v_init, c_init = cp.initialize()
    if which == "both":

        v_vfi, c_vfi = _solve_via_vfi(cp, v_init, return_both=True)
        c_pfi = _solve_via_pfi(cp, c_init)

        # Store solutions in chunked arrays...
        write_array(f, grp, c_vfi, "c_vfi")
        write_array(f, grp, v_vfi, "v_vfi")
        write_array(f, grp, c_pfi, "c_pfi")

        return v_vfi, c_vfi, c_pfi

    elif which == "vfi":
        v_vfi, c_vfi = _solve_via_vfi(cp, v_init, return_both=True)
        write_array(f, grp, c_vfi, "c_vfi")
        write_array(f, grp, v_vfi, "v_vfi")

        return v_vfi, c_vfi

    elif which == "pfi":
        c_pfi = _solve_via_pfi(cp, c_init)
        write_array(f, grp, c_pfi, "c_pfi")

        return c_pfi

def _new_solutions(cp, f, grp, which="both"):
    v_init, c_init = cp.initialize()
    if which == "both":

        v_vfi, c_vfi = _solve_via_vfi(cp, v_init, return_both=True)
        c_pfi = _solve_via_pfi(cp, c_init)

        # Store solutions in chunked arrays...
        write_array(f, grp, c_vfi, "c_vfi")
        write_array(f, grp, v_vfi, "v_vfi")
        write_array(f, grp, c_pfi, "c_pfi")

        return v_vfi, c_vfi, c_pfi

    elif which == "vfi":
        v_vfi, c_vfi = _solve_via_vfi(cp, v_init, return_both=True)
        write_array(f, grp, c_vfi, "c_vfi")
        write_array(f, grp, v_vfi, "v_vfi")

        return v_vfi, c_vfi

    elif which == "pfi":
        c_pfi = _solve_via_pfi(cp, c_init)
        write_array(f, grp, c_pfi, "c_pfi")

        return c_pfi