daily_reduce¶
- earthkit.transforms.temporal.daily_reduce(dataarray: Dataset | DataArray, how: str | Callable = 'mean', time_dim: str | None = None, **kwargs) Dataset | DataArray[source]¶
Group data by day and reduce using the given how method.
- Parameters:
dataarray (xarray.DataArray) – DataArray containing 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, 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 array over an integer valued axis
time_dim (str) – Name of the time dimension, or coordinate, in the xarray object, default behaviour is to deduce time dimension from attributes of coordinates, then fall back to “time”.
time_shift (None, timedelta, dict, str or xarray.DataArray, optional) – A time shift to apply to the data prior to calculation, e.g. to change the local time zone. It can be provided as any object that can be understood by pandas.Timedelta, a dictionary is passed as kwargs to pandas.Timedelta. A string that cannot be parsed as a timedelta is interpreted as a reference to a coordinate of the input dataarray, allowing, e.g., for spatially-varying per-gridpoint time zone offsets. An xarray.DataArray can also be provided directly. Default is None.
remove_partial_periods (bool) – If True and a time_shift has been applied, the first and last time steps are removed to ensure equality in sampling periods. Default is False.
how_label (str) – Label to append to the name of the variable in the reduced object, default is _daily_{how}
extra_reduce_dims (str or list of str) – Additional dimensions to reduce over (in addition to the grouping dimension), for example to calculate a daily global mean you would set this to “longitude” and “latitude”. Default is None.
**kwargs – Keyword arguments to be passed to
reduce().
- Returns:
A dataarray reduced to daily values using the specified method
- Return type: