#!/usr/bin/env python
# -*- coding: utf-8 -*-
import xarray as xr
from matplotlib import pyplot as plt
# Load dataset with xarray
ax = plt.subplot(111)
with xr.open_dataset('output_eddy.nc') as h:
    N = 20
    # plot contour every N
    ax.plot((h.speed_contour_longitude[::N].T + 180) % 360 - 180, h.speed_contour_latitude[::N].T, 'r')
    # plot path
    ax.plot((h.longitude + 180) % 360 - 180, h.latitude, 'b', label='eddy path')
    ax.set_aspect('equal')
    ax.legend()
    ax.grid()
plt.show()