def test_input_period_diagnostic(self):
"""Test correct bounds present on time and forecast_period coordinates
for an input period diagnostic."""
expected_time = self.cube.coord("time").copy()
expected_time.bounds = np.array(
[
datetime_to_iris_time(datetime(2017, 2, 17, 3, 0)),
datetime_to_iris_time(datetime(2017, 2, 17, 6, 0)),
],
dtype=TIME_COORDS["time"].dtype,
)
expected_fp = self.cube.coord("forecast_period").copy()
expected_fp.bounds = np.array(
[0, 3 * 3600],
dtype=TIME_COORDS["forecast_period"].dtype,
)
result = relabel_to_period(self.cube_with_bounds, 3)
self.assertEqual(result.coord("time"), expected_time)
self.assertEqual(result.coord("forecast_period"), expected_fp)
def test_basic(self):
"""Test correct bounds present on time and forecast_period coordinates
for instantaneous input."""
expected_time = self.cube.coord("time").copy()
expected_time.bounds = np.array(
[
datetime_to_iris_time(datetime(2017, 2, 17, 5, 0)),
datetime_to_iris_time(datetime(2017, 2, 17, 6, 0)),
],
dtype=TIME_COORDS["time"].dtype,
)
expected_fp = self.cube.coord("forecast_period").copy()
expected_fp.bounds = np.array(
[2 * 3600, 3 * 3600],
TIME_COORDS["forecast_period"].dtype,
)
result = relabel_to_period(self.cube, 1)
self.assertIsInstance(result, Cube)
self.assertEqual(result.coord("time"), expected_time)
self.assertEqual(result.coord("forecast_period"), expected_fp)
def process(cube: cli.inputcube, *, period: int = None):
"""Relabel a diagnostic as a period diagnostic.
Modify an existing diagnostic to represent a period. This will either
relabel an instantaneous diagnostic to be a period diagnostic, or
modify a period diagnostic to have a different period. This may be
useful when trying to combine instantaneous and period diagnostics.
Args:
cube (iris.cube.Cube):
The cube for a diagnostic that will be modified to represent the
required period.
period (int):
The period in hours.
Returns:
iris.cube.Cube:
Cube with metadata updated to represent the required period.
"""
from improver.utilities.temporal import relabel_to_period
return relabel_to_period(cube, period)
def test_zero_period(self):
"""Test error raised when an invalid value for the period is supplied."""
msg = "Only periods of one hour or greater are supported"
with self.assertRaisesRegex(ValueError, msg):
relabel_to_period(self.cube, period=0)
def test_no_period(self):
"""Test error raised when no period supplied."""
msg = "A period must be specified when relabelling a diagnostic"
with self.assertRaisesRegex(ValueError, msg):
relabel_to_period(self.cube)