reduce¶
- earthkit.transforms.climatology.reduce(dataarray: Dataset | DataArray, time_dim: str | None = None, how: str | Callable | None = 'mean', groupby_kwargs: dict | None = None, climatology_range: tuple | list | None = None, **reduce_kwargs)[source]¶
Group data annually over a given frequency and reduce using the specified how method.
- Parameters:
dataarray (xarray.DataArray) – The DataArray over which to calculate the climatological mean. Must contain a time dimension.
how (str or callable) – 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, an earthkit how method or any method compatible with the array namespace of the data. In the case of duplicate names, method selection is first in the order: xarray, earthkit, array_namespace. 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 array over an integer valued axis
frequency (str (optional)) – Frequency used for grouping the data in climatology mode. Typical values include dayofyear, weekofyear, month, year, etc. The full set of accepted options matches those supported by earthkit.transforms._tools.groupby_time. If not provided, the climatology is calculated over the entire period.
bin_widths (int or list (optional)) – If bin_widths is an int, it defines the width of each group bin on the frequency provided by frequency. If bin_widths is a sequence it defines the edges of each bin, allowing for non-uniform bin widths.
time_dim (str (optional)) – Name of the time dimension in the data object, default behaviour is to detect the time dimension from the input object
climatology_range ((list or tuple, optional)) – Start and end year of the period to be used for the reference climatology. Default is to use the entire time-series.
groupby_kwargs (dict) – Any other kwargs that are accepted by earthkit.transforms.aggregate.groupby_time
**reduce_kwargs – Any other kwargs that are accepted by earthkit.transforms.aggregate.reduce (except how)
- Return type: