register_transformation¶

register_transformation(src, dest, /, *, assign_name=True)[source]¶

Register a function that transforms one variable to another, for use with ClimoDataArrayAccessor.to_variable. Transformations should depend only on the initial variable and (optionally) the coordinates.

Parameters

src (str) – The source variable name.
dest (str, tuple, or re.Pattern) – The destination variable name, a tuple of valid destination names, or an re.compile’d pattern matching a set of valid destination names. In the latter two cases, the function must accept a name keyword argument. This is useful if you want to register a single function capable of deriving multiple related variables (e.g., registering the regex r'\Ad.*dy\Z' to return the meridional gradient of an arbitrary variable).
assign_name (bool, optional) – Whether to assign the user-input string as the output xarray.DataArray.name. Default is True.

Examples

In this example, we define a simple derivation to convert pressure to the log-pressure height.

>>> import climopy as climo
>>> from climopy import const
>>> @climo.register_transformation('p', 'z_logp')
... def meridional_coordinate(da):
...     return (const.H * np.log(const.p0 / da)).climo.to_units('km')
>>> da = xr.DataArray([1000, 800, 600, 400], name='p', attrs={'units': 'hPa'})
>>> da.climo.to_variable('z_logp')
<xarray.DataArray 'z_logp' (dim_0: 4)>
array([0.        , 1.56200486, 3.57577937, 6.41403512])
Dimensions without coordinates: dim_0
Attributes:
    units:    kilometer