import numpy as np
    import matplotlib.pyplot as plt

    fname = 'Akatsuki Venus Osculating Elements daily horizons_results.txt'

    with open(fname, 'r') as infile:
        lines = infile.readlines()

    print(len(lines))

    iSOE = [i for i, line in enumerate(lines) if "$$SOE" in line][0]
    iEOE = [i for i, line in enumerate(lines) if "$$EOE" in line][0]

    istart = 7 + 13
    lines = [line.split(',') for line in lines[iSOE+1+istart:iEOE]]

    data = np.array([[float(thing) for thing in line[2:-1]]for line in lines])
    JD = np.array([float(line[0]) for line in lines])
    years = 2016 + (JD - 2457388.5)/365.2564


    EC, QR, IN, OM, W, Tp, N, MA, TA, A, AD, PR = data.T

    things = EC, IN, OM, W, A
    names = 'Ecc', 'Inc(°)', 'Ω(°)', 'ω(°)', 'a(km)'

    goodies = list(zip(things, names))
    fig, axes = plt.subplots(len(goodies), 1)
    for ax, (thing, name) in zip(axes, goodies):
        ax.plot(years, thing)
        ax.set_ylabel(name)
    plt.suptitle('Akatsuki osculating elements (JPL Horizons)')
    plt.show()

    """
          EC     Eccentricity, e
          QR     Periapsis distance, q (km)
          IN     Inclination w.r.t X-Y plane, i (degrees)
          OM     Longitude of Ascending Node, OMEGA, (degrees)
          W      Argument of Perifocus, w (degrees)
          Tp     Time of periapsis (Julian Day Number)
          N      Mean motion, n (degrees/sec)
          MA     Mean anomaly, M (degrees)
          TA     True anomaly, nu (degrees)
          A      Semi-major axis, a (km)
          AD     Apoapsis distance (km)
          PR     Sidereal orbit period (sec)
    """