Update EISMap (#50)

* refactor EISMap to not modify metadata in place

* fixup eismap tests

* pin sunpy to >=3.1

* pin to sunpy>=4.0

* bumpy py version in CI

* fix py version number

* unpin sphinx

* simplify date property

.github/workflows/tests.yml

@@ -13,9 +13,9 @@ jobs:
       fail-fast: false
       matrix:
         include:
-        - python-version: 3.7
         - python-version: 3.8
         - python-version: 3.9
+        - python-version: '3.10'
     steps:
       - name: Checkout
         uses: actions/checkout@v2.3.1

eispac/core/eismap.py

@@ -7,9 +7,9 @@
 import astropy.units as u
 from astropy.visualization import ImageNormalize, AsinhStretch, LinearStretch
 import sunpy.map
+from sunpy.map.mapbase import SpatialPair
 from sunpy.time import parse_time
 
-
 __all__ = ['EISMap']
 
 
@@ -23,7 +23,7 @@ class EISMap(sunpy.map.GenericMap):
     contributions from ESA and Norway. Hinode was launched on September 22, 2006
     at 21:36 UTC from the Uchinoura Space Center in Japan and continues to
     operate. EIS observes two wavelength ranges in the extreme ultraviolet,
-    171—212Å and 245—291Å with a spectral resolution of about 22mÅ and a plate
+    171—212 Å and 245—291 Å with a spectral resolution of about 22 mÅ and a plate
     scale of 100 per pixel.
 
     This data structure is designed to hold the fit parameters derived from multi-gaussian
@@ -61,29 +61,10 @@ def __init__(self, data, header=None, **kwargs):
 
         super().__init__(data, header, **kwargs)
 
-        # Validate important keywords and add them in, if missing
-        self.meta['ctype1'] = self.meta.get('ctype1', 'HPLN-TAN')
-        self.meta['ctype2'] = self.meta.get('ctype2', 'HPLT-TAN')
-        self.meta['cunit1'] = self.meta.get('cunit1', 'arcsec')
-        self.meta['cunit2'] = self.meta.get('cunit2', 'arcsec')
-        self.meta['waveunit'] = self.meta.get('waveunit', 'angstrom')
-        self.meta['date-beg'] = self.meta.get('date_beg', self.meta.get('date_obs'))
-        self.meta['date-end'] = self.meta.get('date_end')
-        self.meta['date-obs'] = self.meta.get('date_obs')
-        self.meta['date-avg'] = self.meta.get('date_avg')
-        # NOTE: this block can be removed once sunpy>=3.1 is only supported as
-        # the .date_average property will always be constructed in this way if
-        # date_start and date_end are present
-        if self.meta['date-avg'] is None:
-            if self.meta['date-beg'] is not None and self.meta['date-end'] is not None:
-                timesys = self.meta.get('timesys', 'UTC').lower()
-                start = parse_time(self.meta['date-beg'], scale=timesys)
-                end = parse_time(self.meta['date-end'], scale=timesys)
-                self.meta['date-avg'] = (start + (end - start)/2).isot
-
         # Setup plot settings
         self.plot_settings['aspect'] = self.meta['cdelt2'] / self.meta['cdelt1']
-        # self.plot_settings['interpolation'] = 'kaiser' # KEEP FOR REFERENCE
+        # Adjust colormap and normalization depending on whether the map contains
+        # intensity, velocity, or line width data
         if self.meta['measrmnt'].lower().startswith('int'):
             self.plot_settings['cmap'] = 'Blues_r'
             self.plot_settings['norm'] = ImageNormalize(stretch=AsinhStretch())
@@ -95,45 +76,72 @@ def __init__(self, data, header=None, **kwargs):
         elif self.meta['measrmnt'].lower().startswith('wid'):
             self.plot_settings['cmap'] = 'viridis'
 
-    @classmethod
-    def is_datasource_for(cls, data, header, **kwargs):
-        """
-        Determines if header corresponds to an EIS image. Used to register
-        EISMap with the sunpy.map.Map factory.
-        """
-        return str(header.get('instrume', '')).startswith('EIS')
+    @property
+    def spatial_units(self):
+        units = self.meta.get('cunit1', 'arcsec'), self.meta.get('cunit2', 'arcsec')
+        return SpatialPair(u.Unit(units[0]), u.Unit(units[1]))
 
     @property
-    def observatory(self):
-        return 'Hinode'
+    def processing_level(self):
+        return self.meta.get('lvl_num', 3)
 
     @property
-    def measurement(self):
-        line_id = self.meta.get('line_id', '')
-        quantity = self.meta.get('measrmnt', '')
-        return  f'{line_id} {quantity}'
+    def waveunit(self):
+        return u.Unit(self.meta.get('waveunit', 'angstrom'))
 
     @property
     def wavelength(self):
         line_id = self.meta.get('line_id')
         if line_id is not None:
             wave = float(line_id.split()[-1])
-            return u.Quantity(wave, self.meta['waveunit'])
+            return u.Quantity(wave, self.waveunit)
 
     @property
-    def date(self):
-        # Want to make sure we are constructing our coordinate frames
-        # from DATE_AVG and not the DATE-OBS which is the beginning of
-        # the observation
-        # In sunpy 3.1, this may not be needed as we could just remove
-        # date-obs and then .date will default to .date_average
-        t = self.meta.get('date-avg')
-        timesys = self.meta.get('timesys', 'UTC')
-        if t is None:
-            return super().date
-        else:
-            return parse_time(t, scale=timesys.lower())
+    def measurement(self):
+        return self.meta.get('measrmnt', '')
 
     @property
-    def processing_level(self):
-        return self.meta.get('lvl_num', 3)
+    def observatory(self):
+        return 'Hinode'
+
+    @property
+    def nickname(self):
+        line_id = self.meta.get('line_id', '')
+        return f'{self.observatory} {self.instrument} {line_id}'
+
+    @property
+    def date_start(self):
+        # Try default key DATE-BEG. This is to future proof against
+        # switching to DATE-BEG when constructing the L1 headers
+        # NOTE: the DATE_OBS key is the beginning of the observation
+        # so we can use this in case DATE_BEG is missing
+        date_beg = self._get_date('date_beg') or super().date_start
+        date_beg = date_beg or self._date_obs
+        return date_beg
+
+    @property
+    def date_end(self):
+        # Try default key DATE-END. This is to future proof against
+        # switching to DATE-END when constructing the L1 headers
+        return self._get_date('date_end') or super().date_end
+
+    @property
+    def date_average(self):
+        return self._get_date('date_avg') or super().date_average
+
+    @property
+    def date(self):
+        # NOTE: we override this property to prioritize date_average 
+        # over DATE-OBS (or DATE_OBS). In GenericMap, this is reversed.
+        # We do this because we want to make sure we are constructing our 
+        # coordinate frames from DATE_AVG (the midpoint of the raster) and 
+        # not DATE-OBS which is the beginning of the raster.
+        return self.date_average or super().date
+
+    @classmethod
+    def is_datasource_for(cls, data, header, **kwargs):
+        """
+        Determines if header corresponds to an EIS image. Used to register
+        EISMap with the sunpy.map.Map factory.
+        """
+        return str(header.get('instrume', '')).startswith('EIS')

eispac/tests/test_eismap.py

@@ -7,12 +7,10 @@
 import numpy as np
 import pytest
 from astropy.io import fits
-import astropy.time
 import astropy.units as u
 from astropy.visualization import ImageNormalize, AsinhStretch
 import sunpy
 import sunpy.map
-from sunpy.time import parse_time
 
 # This registers the EISMap map class
 import eispac  # NOQA
@@ -77,67 +75,64 @@ def test_wavelength(test_eis_map):
 
 
 def test_measurement(test_eis_map):
-    assert test_eis_map.measurement == 'Fe XII 195.119 intensity'
+    assert test_eis_map.measurement == 'intensity'
+
+
+def test_nickname(test_eis_map):
+    assert test_eis_map.nickname == 'Hinode EIS Fe XII 195.119'
 
 
 def test_processing_level(test_eis_map):
     assert test_eis_map.processing_level == 3
 
 
-def test_plot_settings(test_eis_map):
-    assert test_eis_map.plot_settings['cmap'] == 'Blues_r'
-    assert isinstance(test_eis_map.plot_settings['norm'], ImageNormalize)
-    assert isinstance(test_eis_map.plot_settings['norm'].stretch, AsinhStretch)
-    scale = test_eis_map.scale.axis2 / test_eis_map.scale.axis1
-    assert test_eis_map.plot_settings['aspect'] == scale.decompose().value
+def test_spatial_units(test_eis_map):
+    assert test_eis_map.spatial_units[0] == u.arcsec
+    assert test_eis_map.spatial_units[1] == u.arcsec
+
+
+def test_waveunit(test_eis_map):
+    assert test_eis_map.waveunit == u.Angstrom
+
+
+@pytest.mark.parametrize('attr,key', [
+    ('date_start', 'date_beg'),
+    ('date_end', 'date_end'),
+    ('date_average', 'date_avg'),
+])
+def test_date_props(test_eis_map, attr, key):
+    assert getattr(test_eis_map, attr).isot == test_eis_map.meta[key]
 
 
 def test_date(test_eis_map, test_header):
-    # NOTE: these tests will change slightly with sunpy 3.1 decause of the existence of
-    # date-beg, date-end, and date-avg keys
-    # Case 1: date_obs and date_end exist
-    assert test_eis_map.meta['date-beg'] == test_eis_map.meta['date_beg']
-    assert test_eis_map.meta['date-end'] == test_eis_map.meta['date_end']
-    assert test_eis_map.meta['date-obs'] == test_eis_map.meta['date_obs']
-    assert test_eis_map.meta['date-avg'] == test_eis_map.meta['date_avg']
-    assert test_eis_map.date.isot == test_eis_map.meta['date-avg']
-    # Case 2: date_beg does not exist
+    # Case 1: date-average exists
+    assert test_eis_map.date.isot == test_eis_map.meta['date_avg']
+    # Case 2: date-average is None so default to date_obs
     header = copy.deepcopy(test_header)
     del header['date_beg']
+    del header['date_end']
+    del header['date_avg']
     new_map = sunpy.map.Map(test_eis_map.data, header)
-    assert new_map.meta['date-beg'] == new_map.meta['date_obs']
-    # Case 3: date_avg does not exist
+    assert new_map.date.isot == new_map.meta['date_obs']
+    # Case 3: date_avg is None so default to date_start
     header = copy.deepcopy(test_header)
     del header['date_avg']
+    del header['date_end']
+    del header['date_obs']
     new_map = sunpy.map.Map(test_eis_map.data, header)
-    start = parse_time(new_map.meta['date-beg'], scale='utc')
-    end = parse_time(new_map.meta['date-end'], scale='utc')
-    avg = start + (end - start)/2
-    assert new_map.meta['date-avg'] == avg.isot
-    assert new_map.date == avg
+    assert new_map.date.isot == new_map.meta['date_beg']
     # Case 4: date_end and date_avg do not exist
     header = copy.deepcopy(test_header)
     del header['date_avg']
-    del header['date_end']
+    del header['date_beg']
+    del header['date_obs']
     new_map = sunpy.map.Map(test_eis_map.data, header)
-    assert new_map.date.isot == new_map.meta['date-obs']
+    assert new_map.date.isot == new_map.meta['date_end']
 
 
-def test_missing_date_raises_warning(test_eis_map, test_header):
-    header = copy.deepcopy(test_header)
-    del header['date_end']
-    del header['date_obs']
-    del header['date_beg']
-    del header['date_avg']
-    now = astropy.time.Time.now()
-    new_map = sunpy.map.Map(test_eis_map.data, header)
-    # This raises a slightly different warning in in sunpy>=3.1
-    version = float('.'.join(sunpy.__version__.split('.')[:-1]))
-    if version >= 3.1:
-        from sunpy.util.exceptions import SunpyMetadataWarning
-        expected_warning = SunpyMetadataWarning
-    else:
-        from sunpy.util.exceptions import SunpyUserWarning
-        expected_warning = SunpyUserWarning
-    with pytest.warns(expected_warning, match='Missing metadata for observation time'):
-        assert new_map.date - now < 1*u.s
+def test_plot_settings(test_eis_map):
+    assert test_eis_map.plot_settings['cmap'] == 'Blues_r'
+    assert isinstance(test_eis_map.plot_settings['norm'], ImageNormalize)
+    assert isinstance(test_eis_map.plot_settings['norm'].stretch, AsinhStretch)
+    scale = test_eis_map.scale.axis2 / test_eis_map.scale.axis1
+    assert test_eis_map.plot_settings['aspect'] == scale.decompose().value

setup.cfg

@@ -31,7 +31,7 @@ install_requires =
     matplotlib>=3.1
     h5py>=2.9
     astropy>=3.1
-    sunpy[net,map]>=2.1
+    sunpy[net,map]>=4.0
     ndcube>=2.0.0
     parfive>=1.5
     python-dateutil>=2.8
@@ -41,7 +41,7 @@ test =
     pytest>=4.6.3
     pytest-astropy
 docs =
-    sphinx==4.0.2  # why is this pinned so strictly?
+    sphinx>=4.0.2  # why is this pinned so strictly?
     sphinx-automodapi>=0.13
     sphinx-rtd-theme