def test_get_speeds():

    trajs = Trajectories(data.brownian_trajs_df())
    speeds = trajs.get_speeds().tolist()

    real_speeds = [np.nan,
                   np.nan,
                   np.nan,
                   np.nan,
                   np.nan,
                   857.99153458573994,
                   1596.9530747771976,
                   873.15267834726137,
                   1282.3088174598233,
                   408.98588960526808,
                   378.40023709328955,
                   1809.9895146014187,
                   917.93227668556324,
                   592.31881736181106,
                   0.48325048326444919,
                   0.39551116881922965,
                   798.29858694043128,
                   1085.3214310682606,
                   405.49164945495221,
                   550.37555144616226,
                   1406.707586739079,
                   1031.9444945962532,
                   1077.6619763794718,
                   1445.7789239945778,
                   739.66839622816326]

    assert_almost_equal(speeds, real_speeds)