2020-01-16 15:28:23,767 ERROR    run_lastfew_vec cannot make last_few_vec plot
Traceback (most recent call last):
  File "/usr/local/currents/bin/run_lastfew_vec.py", line 106, in <module>
    data = LFV.get_data()
  File "/usr/local/lib/python2.7/dist-packages/pycurrents/adcp/plot_lastfew_vec.py", line 114, in get_data
    platstr = navcalc.pretty_llstr(self.data.lat[-1],'lat')
  File "/usr/local/lib/python2.7/dist-packages/pycurrents/data/navcalc.py", line 366, in pretty_llstr
    'lon': {-1:'W', 1:'E'}}[ptype][np.sign(wrapped)]
TypeError: unhashable type: 'MaskedConstant'