xarray.Dataset.map#

Dataset.map(func, keep_attrs=None, args=(), **kwargs)[source]#

Apply a function to each data variable in this dataset

Parameters:

  • func (callable()) – Function which can be called in the form func(x, *args, **kwargs) to transform each DataArray x in this dataset into another DataArray.

  • keep_attrs (bool or None, optional) – If True, both the dataset’s and variables’ attributes (attrs) will be copied from the original objects to the new ones. If False, the new dataset and variables will be returned without copying the attributes.

  • args (iterable, optional) – Positional arguments passed on to func.

  • **kwargs (Any) – Keyword arguments passed on to func.

Returns:

applied (Dataset) – Resulting dataset from applying func to each data variable.

Examples

>>> da = xr.DataArray(np.random.randn(2, 3))
>>> ds = xr.Dataset({"foo": da, "bar": ("x", [-1, 2])})
>>> ds
<xarray.Dataset>
Dimensions:  (dim_0: 2, dim_1: 3, x: 2)
Dimensions without coordinates: dim_0, dim_1, x
Data variables:
    foo      (dim_0, dim_1) float64 1.764 0.4002 0.9787 2.241 1.868 -0.9773
    bar      (x) int64 -1 2
>>> ds.map(np.fabs)
<xarray.Dataset>
Dimensions:  (dim_0: 2, dim_1: 3, x: 2)
Dimensions without coordinates: dim_0, dim_1, x
Data variables:
    foo      (dim_0, dim_1) float64 1.764 0.4002 0.9787 2.241 1.868 0.9773
    bar      (x) float64 1.0 2.0