Unhashable type MaskedNDArray

[retifrav]

This problem can be reproduced after #77 is fixed.

There is some error in wrap_characterization_of_flares() function on the line fl = fl.merge(flcc):

TypeError: unhashable type: 'MaskedNDArray'

Full error output, just in case

Traceback (most recent call last):
  File "/path/to/some.py", line 33, in <module>
    flcc = flcd.characterize_flares(ampl_bins=10, dur_bins=10)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/path/to/AltaiPony/altaipony/flarelc.py", line 947, in characterize_flares
    flares = wrap_characterization_of_flares(flc.fake_flares, flc.flares,
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/path/to/AltaiPony/altaipony/injrecanalysis.py", line 54, in wrap_characterization_of_flares
    fl = fl.merge(flcc)
         ^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/pandas/core/frame.py", line 9843, in merge
    return merge(
           ^^^^^^
  File "/usr/local/lib/python3.11/site-packages/pandas/core/reshape/merge.py", line 162, in merge
    return op.get_result(copy=copy)
           ^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/pandas/core/reshape/merge.py", line 809, in get_result
    join_index, left_indexer, right_indexer = self._get_join_info()
                                              ^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/pandas/core/reshape/merge.py", line 1065, in _get_join_info
    (left_indexer, right_indexer) = self._get_join_indexers()
                                    ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/pandas/core/reshape/merge.py", line 1038, in _get_join_indexers
    return get_join_indexers(
           ^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/pandas/core/reshape/merge.py", line 1665, in get_join_indexers
    zipped = zip(*mapped)
             ^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/pandas/core/reshape/merge.py", line 1662, in <genexpr>
    _factorize_keys(left_keys[n], right_keys[n], sort=sort, how=how)
  File "/usr/local/lib/python3.11/site-packages/pandas/core/reshape/merge.py", line 2442, in _factorize_keys
    llab = rizer.factorize(lk)  # type: ignore[arg-type]
           ^^^^^^^^^^^^^^^^^^^
  File "pandas/_libs/hashtable.pyx", line 122, in pandas._libs.hashtable.ObjectFactorizer.factorize
  File "pandas/_libs/hashtable_class_helper.pxi", line 7288, in pandas._libs.hashtable.PyObjectHashTable.get_labels
  File "pandas/_libs/hashtable_class_helper.pxi", line 7194, in pandas._libs.hashtable.PyObjectHashTable._unique
TypeError: unhashable type: 'MaskedNDArray'

I get it when I call characterize_flares() function.

A script to reproduce the problem

from altaipony.lcio import from_mast
import pandas

flc = from_mast(
    "Kepler-114",
    mode="LC",
    cadence="short",
    mission="Kepler"
)

for j in range(len(flc)):
    print(f"\n--- {j} ---\n")
    # detrend curve
    flcd = flc[j].detrend("savgol")
    # find flares
    flcd = flcd.find_flares(N1=3, N2=1, N3=3, minsep=3)
    flcdpanda = flcd.flares
    # print(flcdpanda)
    if not flcdpanda.empty:
        # injection of simulated flares
        flcd, fakeflc = flcd.sample_flare_recovery(
            inject_before_detrending=True,
            mode="savgol",
            iterations=20,
            fakefreq=2,
            ampl=[1e-4, 0.5],
            dur=[.001/6., 0.1/6.]
        )
        print(f"Total number of injected flares is {flcd.fake_flares.shape[0]}")

        # here it fails
        flcc = flcd.characterize_flares(ampl_bins=10, dur_bins=10)
    else:
        print("DataFrame is empty, no flares")

Since it was working fine before in older versions of AltaiPony (the ones using older Astropy depedcency, such as v4.3.1), this problem is likely caused by something from newer Astropy versions.

Tested with aa6ba8d revision.