grid_process.units_conv

Module to control, parse and convert units

Attributes

logger
dataarray_accessor
dataset_accessor
ureg

Exceptions

UnitsError

Class to raise units errors

Classes

DaUnits	Xarray accessors class for units utility functions on DataArray
DsUnits	Xarray accessors class for units utility functions on Dataset

Functions

da_to(→ xarray.DataArray)	Convert units in a xarray.DataArray.
ds_to(→ xarray.Dataset)	Convert units in a xarray.Dataset.
consistency_check(→ dict[str, dict[str, str]])	Checks that the input datasets have same data variables and units. If it is
units_check(→ None)	Check that the data variables in the datasets all have same single units.

Module Contents

logger

exception UnitsError

Bases: Exception

Class to raise units errors

class DaUnits(da: xarray.DataArray)

Xarray accessors class for units utility functions on DataArray

class DsUnits(ds: xarray.Dataset)

Xarray accessors class for units utility functions on Dataset

dataarray_accessor

dataset_accessor

ureg: pint.UnitRegistry

da_to(da: xarray.DataArray, dst_units: str) → xarray.DataArray

Convert units in a xarray.DataArray.

Parameters:

• da (xarray.DataArray) – with attribute “units”

• dst_units (str) – destination units

Returns:

da_out – contains the data array with converted units

Return type:

xarray.DataArray

Raises:

pint.errors.DimensionalityError – if the conversion is not possible

ds_to(ds: xarray.Dataset, dst_units: str | dict[collections.abc.Hashable, str]) → xarray.Dataset

Convert units in a xarray.Dataset.

Parameters:

• ds (xarray.Dataset) – with variable attributes “units”

• dst_units (str or dict) – destination units for each data variable to be converted. Variable names not specified in dst_units are kept in the same units. If passed as a single string, all variables in the dataset are converted to the same units

Returns:

ds_out – contains the dataset with converted units

Return type:

xarray.Dataset

Raises:

pint.errors.DimensionalityError – if the conversion is not possible

consistency_check(datasets: collections.abc.Sequence[xarray.Dataset], check_vars: bool = True) → dict[str, dict[str, str]]

Checks that the input datasets have same data variables and units. If it is the case, returns the ‘units’ attributes of each data variable otherwise raises an error.

Parameters:

• datasets (sequence of xarray.Dataset) – each data variable in the datasets must have a ‘units’ attributes

• check_vars (bool, optional) – if False, allows datasets to have different variables, but common ones must have same units. Default is True

Returns:

out – contains the ‘units’ attribute of the data variables in the input datasets. In case same units are specified in various format, the dominant format is kept if there is one otherwise the format from the first dataset in the input sequence

Return type:

dict

Raises:

• UnitsError – if same variables across the input datasets have different units

• ValueError – when check_vars=True and the input datasets do not have exact same set of variables

units_check(datasets: collections.abc.Sequence[xarray.Dataset]) → None

Check that the data variables in the datasets all have same single units. If not, it raises an error.

Parameters:

datasets (sequence of xarray.Dataset) – each data variable in the datasets must have a ‘units’ attributes

Raises:

UnitsError – if any variable in any of the input datasets have different units