unexpected behavior when handling np.ma.core.MaskedArray

[jdduprey]

I was trying out the wav_write function and noticed some behavior I don't quite understand.

start_time = datetime(2019,1,12,3)
end_time = datetime(2019,1,12,3,1)
node = 'LJ01C'

hdata = ooipy.get_acoustic_data(start_time, end_time, node, verbose=True)

Fetching URLs...
Sorting valid URLs for Time Window...
Downloading mseed files...
100%|█████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████| 4/4 [00:05<00:00, 1.41s/it]
file fragmented but timestamps are unique. Segment kept
Merging 4 Traces...
Data has Gaps

The logs warn me the data have gaps. This is becuase hdata.data is a masked array.

masked_array(data=[27445.0, 27944.0, 28181.0, ..., 28364.0, 28849.0,
                   29322.0],
             mask=[False, False, False, ..., False, False, False],
       fill_value=1e+20)

But when I call the data directly:
np.unique(hdata.data.mask)
array([False])
So it appears there arn't actually any gaps. Is this due to using obspy merge method zero by default?

Finally - I think the masked array may be causing problems with wav_write. Unless wav_write should be deprecated and save is the method to use?

hdata.wav_write("hyd_output/test2.wav", norm=False)

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
File [~/miniconda3/envs/ooipy/lib/python3.11/site-packages/numpy/ma/core.py:3251](http://localhost:8890/lab/workspaces/auto-l/tree/HYD/~/miniconda3/envs/ooipy/lib/python3.11/site-packages/numpy/ma/core.py#line=3250), in MaskedArray.view(self, dtype, type, fill_value)
   3250 try:
-> 3251     if issubclass(dtype, ndarray):
   3252         output = ndarray.view(self, dtype)

TypeError: issubclass() arg 1 must be a class

During handling of the above exception, another exception occurred:

ValueError                                Traceback (most recent call last)
Cell In[13], line 1
----> 1 hdata.wav_write("hyd_output[/test2.wav](http://localhost:8890/test2.wav)", norm=False)

File [~/repos/ooipy/src/ooipy/hydrophone/basic.py:527](http://localhost:8890/lab/workspaces/auto-l/tree/HYD/~/repos/ooipy/src/ooipy/hydrophone/basic.py#line=526), in HydrophoneData.wav_write(self, filename, norm, new_sample_rate)
    524             data = signal.decimate(data, int(self.stats.sampling_rate [/](http://localhost:8890/) new_sample_rate))
    525             sampling_rate = new_sample_rate
--> 527 wavfile.write(filename, int(sampling_rate), data)

File [~/miniconda3/envs/ooipy/lib/python3.11/site-packages/scipy/io/wavfile.py:870](http://localhost:8890/lab/workspaces/auto-l/tree/HYD/~/miniconda3/envs/ooipy/lib/python3.11/site-packages/scipy/io/wavfile.py#line=869), in write(filename, rate, data)
    867 if data.dtype.byteorder == '>' or (data.dtype.byteorder == '=' and
    868                                    sys.byteorder == 'big'):
    869     data = data.byteswap()
--> 870 _array_tofile(fid, data)
    872 # Determine file size and place it in correct
    873 # position at start of the file or the data chunk.
    874 size = fid.tell()

File [~/miniconda3/envs/ooipy/lib/python3.11/site-packages/scipy/io/wavfile.py:891](http://localhost:8890/lab/workspaces/auto-l/tree/HYD/~/miniconda3/envs/ooipy/lib/python3.11/site-packages/scipy/io/wavfile.py#line=890), in _array_tofile(fid, data)
    889 def _array_tofile(fid, data):
    890     # ravel gives a c-contiguous buffer
--> 891     fid.write(data.ravel().view('b').data)

File [~/miniconda3/envs/ooipy/lib/python3.11/site-packages/numpy/ma/core.py:3257](http://localhost:8890/lab/workspaces/auto-l/tree/HYD/~/miniconda3/envs/ooipy/lib/python3.11/site-packages/numpy/ma/core.py#line=3256), in MaskedArray.view(self, dtype, type, fill_value)
   3255             output = ndarray.view(self, dtype)
   3256     except TypeError:
-> 3257         output = ndarray.view(self, dtype)
   3258 else:
   3259     output = ndarray.view(self, dtype, type)

File [~/miniconda3/envs/ooipy/lib/python3.11/site-packages/numpy/ma/core.py:3490](http://localhost:8890/lab/workspaces/auto-l/tree/HYD/~/miniconda3/envs/ooipy/lib/python3.11/site-packages/numpy/ma/core.py#line=3489), in MaskedArray.dtype(self, dtype)
   3487 # Try to reset the shape of the mask (if we don't have a void).
   3488 # This raises a ValueError if the dtype change won't work.
   3489 try:
-> 3490     self._mask.shape = self.shape
   3491 except (AttributeError, TypeError):
   3492     pass

ValueError: cannot reshape array of size 3840001 into shape (30720008,)