Maths operations on cubes with unstructured grid cause a TypeError in resolve() #4454
Description
🐛 Bug Report
I am using the dev version of iris to work with unstructured grids (LFRic output). The issue I am having is that all maths operations seem to be broken: a TypeError is raised when the maths operation calls resolver.cube(), which in turn invokes the container() method on an auxiliary coordinate with an unexpected keyword bounds (see the full message below). This happens even if the RHS and LHS cubes are the same cube, but it doesn't happen if operations are unary, such as raising the cube to the power.
How To Reproduce
Steps to reproduce the behaviour:
import os
import iris
from iris.experimental.ugrid import PARSE_UGRID_ON_LOAD
test_data_dir = iris.config.TEST_DATA_DIR
src_fn = os.path.join(
test_data_dir, "NetCDF", "unstructured_grid", "lfric_ngvat_3D_1t_half_level_face_grid_derived_theta_in_w3.nc"
)
with PARSE_UGRID_ON_LOAD.context():
theta = iris.load_cube(src_fn, "air_potential_temperature")
foo = theta + thetaThis results in "TypeError: __init__() got an unexpected keyword argument 'bounds'"
---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
/tmp/ipykernel_33999/786035974.py in <module>
----> 1 theta + theta
~/mambaforge/envs/ideal_exo/lib/python3.8/site-packages/iris/common/lenient.py in lenient_client_inner(*args, **kwargs)
122 """
123 with _LENIENT.context(*services, active=_qualname(func)):
--> 124 result = func(*args, **kwargs)
125 return result
126
~/mambaforge/envs/ideal_exo/lib/python3.8/site-packages/iris/analysis/maths.py in add(cube, other, dim, in_place)
231 else:
232 op = operator.add
--> 233 return _add_subtract_common(
234 op, "add", cube, other, new_dtype, dim=dim, in_place=in_place
235 )
~/mambaforge/envs/ideal_exo/lib/python3.8/site-packages/iris/analysis/maths.py in _add_subtract_common(operation_function, operation_name, cube, other, new_dtype, dim, in_place)
322 raise iris.exceptions.NotYetImplementedError(emsg)
323
--> 324 result = _binary_op_common(
325 operation_function,
326 operation_name,
~/mambaforge/envs/ideal_exo/lib/python3.8/site-packages/iris/analysis/maths.py in _binary_op_common(operation_function, operation_name, cube, other, new_unit, new_dtype, dim, in_place)
824 # Insert the resultant data from the maths operation
825 # within the resolved cube.
--> 826 result = resolver.cube(result.core_data(), in_place=in_place)
827 _sanitise_metadata(result, new_unit)
828
~/mambaforge/envs/ideal_exo/lib/python3.8/site-packages/iris/common/resolve.py in cube(self, data, in_place)
2344 )
2345 for item in prepared_aux_coords:
-> 2346 coord = item.container(item.points, bounds=item.bounds)
2347 coord.metadata = item.metadata.combined
2348 try:
TypeError: __init__() got an unexpected keyword argument 'bounds'Expected behaviour
The expected behaviour is obviously that the maths works :)
Environment
- OS & Version: Ubuntu 20.04 LTS
- Iris Version: 3.2.dev0