def um_to_pp(filename, read_data=False, word_depth=None):
"""
Extract individual PPFields from within a UM Fieldsfile-like file.
Returns an iterator over the fields contained within the FieldsFile,
returned as :class:`iris.fileformats.pp.PPField` instances.
Args:
* filename (string):
Specify the name of the FieldsFile.
Kwargs:
* read_data (boolean):
Specify whether to read the associated PPField data within
the FieldsFile. Default value is False.
Returns:
Iteration of :class:`iris.fileformats.pp.PPField`.
For example::
>>> for field in um.um_to_pp(filename):
... print(field)
"""
if word_depth is None:
ff2pp = FF2PP(filename, read_data=read_data)
else:
ff2pp = FF2PP(filename, read_data=read_data, word_depth=word_depth)
# Note: unlike the original wrapped case, we will return an actual
# iterator, rather than an object that can provide an iterator.
return iter(ff2pp)
def test__bad_lbvc(self):
self.mock_field.lbvc = 312
ff2pp = FF2PP("dummy_filename")
with self.assertRaisesRegex(
ValueError, "LBVC of 312, expected only 0 or 65"
):
ff2pp._adjust_field_for_lbc(self.mock_field)
def test__bad_lbtim(self):
self.mock_field.lbtim = 717
ff2pp = FF2PP("dummy_filename")
with self.assertRaisesRegex(
ValueError, "LBTIM of 717, expected only 0 or 11"
):
ff2pp._adjust_field_for_lbc(self.mock_field)
def test_decreasing_field_values(self):
# Field where its values a decreasing.
ff2pp = FF2PP("dummy")
field_x = np.array([3, 2, 1])
com = np.array([4, 3, 2, 1, 0])
result = ff2pp._det_border(field_x, 1)
self.assertArrayEqual(result, com)
def test_increasing_field_values(self):
# Field where its values a increasing.
ff2pp = FF2PP('dummy')
field_x = np.array([1, 2, 3])
com = np.array([0, 1, 2, 3, 4])
result = ff2pp._det_border(field_x, 1)
self.assertArrayEqual(result, com)
def test__lbhem_too_large(self):
ff2pp = FF2PP("dummy_filename")
field = self.mock_field
field.lbhem = 105
with self.assertRaisesRegex(
ValueError, "more than the total number of levels in the file = 3"
):
_ = list(ff2pp._fields_over_all_levels(field))
def test__lbhem_too_small(self):
ff2pp = FF2PP('dummy_filename')
field = self.mock_field
field.lbhem = 100
with self.assertRaisesRegex(
ValueError,
'hence >= 101'):
_ = list(ff2pp._fields_over_all_levels(field))
def _test(self, mock_field, expected_depth, expected_dtype,
word_depth=None):
with mock.patch('iris.fileformats._ff.FFHeader', return_value=None):
kwargs = {}
if word_depth is not None:
kwargs['word_depth'] = word_depth
ff2pp = FF2PP('dummy_filename', **kwargs)
data_depth, data_dtype = ff2pp._payload(mock_field)
self.assertEqual(data_depth, expected_depth)
self.assertEqual(data_dtype, expected_dtype)
def test__basic(self):
ff2pp = FF2PP("dummy_filename")
field = self.mock_field
ff2pp._adjust_field_for_lbc(field)
self.assertEqual(field.lbtim, 11)
self.assertEqual(field.lbvc, 65)
self.assertEqual(field.boundary_packing.rim_width, 8)
self.assertEqual(field.boundary_packing.y_halo, 5)
self.assertEqual(field.boundary_packing.x_halo, 4)
self.assertEqual(field.lbnpt, 1009)
self.assertEqual(field.lbrow, 2011)
def test_unequal_spacing_eitherside(self):
# Ensure that we do not interpret the case where there is not the same
# spacing on the lower edge as the upper edge.
ff2pp = FF2PP('dummy')
field_x = np.array([1, 2, 10])
msg = ('The x or y coordinates of your boundary condition field may '
'be incorrect, not having taken into account the boundary '
'size.')
with mock.patch('warnings.warn') as warn:
result = ff2pp._det_border(field_x, None)
warn.assert_called_with(msg)
self.assertIs(result, field_x)
def test__is_lbc(self):
ff2pp = FF2PP("dummy_filename")
field = self.mock_field
results = list(ff2pp._fields_over_all_levels(field))
self._check_expected_levels(results, 3)
