transforms
==========

.. py:module:: transforms


Submodules
----------

.. toctree::
   :maxdepth: 1

   /_api/transforms/climatology/index
   /_api/transforms/ensemble/index
   /_api/transforms/spatial/index
   /_api/transforms/temporal/index


Attributes
----------

.. autoapisummary::

   transforms.tools


Functions
---------

.. autoapisummary::

   transforms.reduce
   transforms.resample
   transforms.rolling_reduce


Package Contents
----------------

.. py:function:: reduce(dataarray, *_args, **kwargs)

   Reduce an xarray.dataarray or xarray.dataset using a specified `how` method.

   With the option to apply weights either directly or using a specified
   `weights` method.

   :param dataarray: Data object to reduce
   :type dataarray: :class:`xr.DataArray` or :class:`xr.Dataset`
   :param how: Method used to reduce data. Default='mean', which will implement the xarray in-built mean.
               If string, it must be an in-built xarray reduce method, a earthkit how method or any numpy method.
               In the case of duplicate names, method selection is first in the order: xarray, earthkit, numpy.
               Otherwise it can be any function which can be called in the form `f(x, axis=axis, **kwargs)`
               to return the result of reducing an xp.ndarray over an integer valued axis
   :type how: :class:`str` or :class:`callable`
   :param weights: Choose a recognised method to apply weighting. Currently available methods are; 'latitude'
   :type weights: :class:`str`
   :param how_label: Label to append to the name of the variable in the reduced object
   :type how_label: :class:`str`
   :param how_dropna: Choose how to drop nan values.
                      Default is None and na values are preserved. Options are 'any' and 'all'.
   :type how_dropna: :class:`str`
   :param \*\*kwargs: kwargs recognised by the how :func: `reduce`

   :rtype: :class:`A data array with reduce dimensions removed.`


.. py:function:: resample(dataarray, frequency, time_dim = 'time', how = 'mean', skipna = True, how_args = [], how_kwargs = {}, how_label = None, **kwargs)

   Resample dataarray to a user-defined frequency using a user-defined "how" method.

   :param dataarray: DataArray to be resampled.
   :type dataarray: :class:`xr.DataArray`
   :param frequency: The frequency at which to resample the chosen dimension. The format must be applicable
                     to the chosen dimension.
   :type frequency: :class:`str`, :class:`int`, :class:`float`
   :param time_dim: The dimension to resample along, default is `time`
   :type time_dim: :class:`str`
   :param how: The reduction method for resampling, default is `mean`
   :type how: :class:`str`
   :param how_label: Label to append to the name of the variable in the reduced object, default is nothing
   :type how_label: :class:`str`
   :param skipna: If True, exclude missing values (na values) from the reduction.
   :type skipna: :class:`bool`
   :param how_args: List of arguments to be passed to the reduction method.
   :type how_args: :class:`list`
   :param how_kwargs: Dictionary of keyword arguments to be passed to the reduction method.
   :type how_kwargs: :class:`dict`
   :param \*\*kwargs: Keyword arguments to be passed to :func:`resample`. Defaults have been set as:
                      `{"skipna": True}`

   :rtype: :class:`xr.Dataset | xr.DataArray`


.. py:function:: rolling_reduce(dataarray, *_args, **kwargs)

   Return reduced data using a moving window over which to apply the reduction.

   :param dataarray: Data over which the moving window is applied according to the reduction method.
   :type dataarray: :class:`xr.DataArray` or :class:`xr.Dataset`
   :param windows: windows for the rolling groups, for example `time=10` to perform a reduction
                   in the time dimension with a bin size of 10. the rolling groups can be defined
                   over any number of dimensions. **see documentation for xarray.dataarray.rolling**.
   :param min_periods: The minimum number of observations in the window required to have a value
                       (otherwise result is NaN). Default is to set **min_periods** equal to the size of the window.
                       **see documentation for xarray.dataarray.rolling**
   :type min_periods: :class:`integer`
   :param center: Set the labels at the centre of the window, **see documentation for xarray.dataarray.rolling**.
   :type center: :class:`bool`
   :param how_reduce: Function to be applied for reduction. Default is 'mean'.
   :type how_reduce: :class:`str,`
   :param how_dropna: Determine if dimension is removed from the output when we have at least one NaN or
                      all NaN. **how_dropna** can be 'None', 'any' or 'all'. Default is 'any'.
   :type how_dropna: :class:`str`
   :param \*\*kwargs: Any kwargs that are compatible with the select `how_reduce` method.

   :rtype: :class:`xr.DataArray` or :class:`xr.Dataset (as provided)`


.. py:data:: tools