Encounter error when reproducing recipe

[Nemo1166]

UFuncTypeError: Cannot cast ufunc 'subtract' output from dtype('float64') to dtype('int64') with casting rule 'same_kind'

Expectation

Same with recipe 1 in documentation.

Reproduction

Run plot_01_recipe.ipynb, with data file cru_ts4.06.1901.2021.tmp.dat.nc (link).

Traceback info

here

``` { "name": "UFuncTypeError", "message": "Cannot cast ufunc 'subtract' output from dtype('float64') to dtype('int64') with casting rule 'same_kind'", "stack": "--------------------------------------------------------------------------- UFuncTypeError Traceback (most recent call last) c:\\Users\\10502\\Desktop\\dataset-derived-near-surface-meteorological-variables-a2eeaa79-acc2-4c4a-9e90-b5b6ecd9c3f9\\plot_01_recipe.ipynb 单元格 22 line 1 ----> 1 annual_global_avg = global_avg.collapse(\"T: mean\", group=cf.Y()) 2 cfp.lineplot( 3 annual_global_avg, 4 color=\"red\", 5 title=\"Annual global mean surface temperature\", 6 ) File c:\\Users\\10502\\miniforge3\\envs\\cf311\\Lib\\site-packages\\cf\\decorators.py:71, in _deprecated_kwarg_check..deprecated_kwarg_check_decorator..precede_with_kwarg_deprecation_check(self, *args, **kwargs) 62 pass_in_kwarg = {depr_kwarg: True} 63 _DEPRECATION_ERROR_KWARGS( 64 self, 65 operation_method.__name__, (...) 68 removed_at=removed_at, 69 ) # pragma: no cover ---> 71 operation_method_result = operation_method(self, *args, **kwargs) 73 # Decorated method has same return signature as if undecorated: 74 return operation_method_result File c:\\Users\\10502\\miniforge3\\envs\\cf311\\Lib\\site-packages\\cfdm\\decorators.py:171, in _manage_log_level_via_verbosity..verbose_override_wrapper(*args, **kwargs) 168 # After method completes, re-set any changes to log level or 169 # enabling 170 try: --> 171 return method_with_verbose_kwarg(*args, **kwargs) 172 except Exception: 173 raise File c:\\Users\\10502\\miniforge3\\envs\\cf311\\Lib\\site-packages\\cf\\field.py:7941, in Field.collapse(self, method, axes, squeeze, mtol, weights, ddof, a, inplace, group, regroup, within_days, within_years, over_days, over_years, coordinate, group_by, group_span, group_contiguous, measure, scale, radius, great_circle, verbose, remove_vertical_crs, _create_zero_size_cell_bounds, _update_cell_methods, i, _debug, **kwargs) 7937 g_weights = None 7939 axis = [a for a in collapse_axes][0] -> 7941 f = f._collapse_grouped( 7942 method, 7943 axis, 7944 within=within, 7945 over=over, 7946 within_days=within_days, 7947 within_years=within_years, 7948 over_days=over_days, 7949 over_years=over_years, 7950 group=group, 7951 group_span=group_span, 7952 group_contiguous=group_contiguous, 7953 regroup=regroup, 7954 mtol=mtol, 7955 ddof=ddof, 7956 measure=measure, 7957 weights=g_weights, 7958 squeeze=squeeze, 7959 coordinate=coordinate, 7960 group_by=group_by, 7961 axis_in=axes_in[0], 7962 verbose=verbose, 7963 ) 7965 if regroup: 7966 # Grouped collapse: Return the numpy array 7967 return f File c:\\Users\\10502\\miniforge3\\envs\\cf311\\Lib\\site-packages\\cfdm\\decorators.py:171, in _manage_log_level_via_verbosity..verbose_override_wrapper(*args, **kwargs) 168 # After method completes, re-set any changes to log level or 169 # enabling 170 try: --> 171 return method_with_verbose_kwarg(*args, **kwargs) 172 except Exception: 173 raise File c:\\Users\\10502\\miniforge3\\envs\\cf311\\Lib\\site-packages\\cf\\field.py:8893, in Field._collapse_grouped(self, method, axis, within, over, within_days, within_years, over_days, over_years, group, group_span, group_contiguous, mtol, ddof, regroup, coordinate, measure, weights, squeeze, group_by, axis_in, verbose) 8887 classification.fill(-1) 8889 lower, upper, lower_limit, upper_limit = _tyu( 8890 coord, group_by, True 8891 ) -> 8893 classification, n = _time_interval( 8894 classification, 8895 0, 8896 coord=coord, 8897 interval=group, 8898 lower=lower, 8899 upper=upper, 8900 lower_limit=lower_limit, 8901 upper_limit=upper_limit, 8902 group_by=group_by, 8903 ) 8905 if group_span is True or group_span is None: 8906 # Use the group definition as the group span 8907 group_span = group File c:\\Users\\10502\\miniforge3\\envs\\cf311\\Lib\\site-packages\\cf\\field.py:8397, in Field._collapse_grouped.._time_interval(classification, n, coord, interval, lower, upper, lower_limit, upper_limit, group_by, extra_condition) 8395 while lower <= upper_limit: 8396 lower, upper = interval.interval(lower) -> 8397 classification, n, lower, upper = _ddddd( 8398 classification, 8399 n, 8400 lower, 8401 upper, 8402 True, 8403 coord, 8404 group_by_coords, 8405 extra_condition, 8406 ) 8407 else: 8408 # Decreasing dimension coordinate 8409 lower, upper = interval.bounds(upper) File c:\\Users\\10502\\miniforge3\\envs\\cf311\\Lib\\site-packages\\cf\\field.py:8336, in Field._collapse_grouped.._ddddd(classification, n, lower, upper, increasing, coord, group_by_coords, extra_condition) 8333 if extra_condition: 8334 q &= extra_condition -> 8336 index = q.evaluate(coord).array 8337 classification[index] = n 8339 if increasing: File c:\\Users\\10502\\miniforge3\\envs\\cf311\\Lib\\site-packages\\cf\\mixin\\propertiesdata.py:2437, in PropertiesData.array(self) 2434 if data is None: 2435 raise AttributeError(f\"{self.__class__.__name__} has no data\") -> 2437 return data.array File c:\\Users\\10502\\miniforge3\\envs\\cf311\\Lib\\site-packages\\cf\\data\\data.py:5096, in Data.array(self) 5054 @property 5055 def array(self): 5056 \"\"\"A numpy array copy of the data. 5057 5058 In-place changes to the returned numpy array do not affect the (...) 5094 5095 \"\"\" -> 5096 array = self.compute().copy() 5097 if not isinstance(array, np.ndarray): 5098 array = np.asanyarray(array) File c:\\Users\\10502\\miniforge3\\envs\\cf311\\Lib\\site-packages\\cf\\data\\data.py:2652, in Data.compute(self) 2620 def compute(self): # noqa: F811 2621 \"\"\"A numpy view the data. 2622 2623 In-place changes to the returned numpy array *might* affect (...) 2650 2651 \"\"\" -> 2652 a = self.to_dask_array().compute() 2654 if np.ma.isMA(a): 2655 if self.hardmask: File c:\\Users\\10502\\miniforge3\\envs\\cf311\\Lib\\site-packages\\dask\\base.py:342, in DaskMethodsMixin.compute(self, **kwargs) 318 def compute(self, **kwargs): 319 \"\"\"Compute this dask collection 320 321 This turns a lazy Dask collection into its in-memory equivalent. (...) 340 dask.compute 341 \"\"\" --> 342 (result,) = compute(self, traverse=False, **kwargs) 343 return result File c:\\Users\\10502\\miniforge3\\envs\\cf311\\Lib\\site-packages\\dask\\base.py:628, in compute(traverse, optimize_graph, scheduler, get, *args, **kwargs) 625 postcomputes.append(x.__dask_postcompute__()) 627 with shorten_traceback(): --> 628 results = schedule(dsk, keys, **kwargs) 630 return repack([f(r, *a) for r, (f, a) in zip(results, postcomputes)]) File c:\\Users\\10502\\miniforge3\\envs\\cf311\\Lib\\site-packages\\cf\\data\\dask_utils.py:643, in cf_units(a, from_units, to_units) 606 def cf_units(a, from_units, to_units): 607 \"\"\"Convert array values to have different equivalent units. 608 609 .. versionadded:: 3.14.0 (...) 641 642 \"\"\" --> 643 return Units.conform( 644 a, from_units=from_units, to_units=to_units, inplace=False 645 ) File c:\\Users\\10502\\miniforge3\\envs\\cf311\\Lib\\site-packages\\cf\\units.py:29, in Units.conform(*args, **kwargs) 27 @staticmethod 28 def conform(*args, **kwargs): ---> 29 return cfUnits.conform(*args, **kwargs) File c:\\Users\\10502\\miniforge3\\envs\\cf311\\Lib\\site-packages\\cfunits\\units.py:2297, in Units.conform(cls, x, from_units, to_units, inplace) 2293 _cv_free(cv_converter) 2295 offset *= scale.item() -> 2297 x -= offset 2299 return x UFuncTypeError: Cannot cast ufunc 'subtract' output from dtype('float64') to dtype('int64') with casting rule 'same_kind'" } ```

Env

# cf.environment(paths=False)
Platform: Windows-10-10.0.22631-SP0
HDF5 library: 1.14.2
netcdf library: 4.9.2
udunits2 library: C:\Users\10502\miniforge3\envs\cf311\Scripts\udunits2.dll
esmpy/ESMF: 8.4.2
Python: 3.11.6
dask: 2023.11.0
netCDF4: 1.6.5
psutil: 5.9.5
packaging: 23.2
numpy: 1.26.2
scipy: 1.11.4
matplotlib: 3.8.2
cftime: 1.6.3
cfunits: 3.3.6
cfplot: 3.2.23
cfdm: 1.10.1.2
cf: 3.15.4

[Nemo1166]

error also occurred when reproducing this in Docs:Analysis.

[Nemo1166]

It seems can be solved by following modification:

In pkg cfunits, file units.py, line 2297:

-  x -= offset
+  x = x - offset

I haven't check other components to avoid potential problems.

[sadielbartholomew]

Thanks for reporting this! We'll look into it soon. I'll comment here with any updates from when we get a chance to work on it.