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 combined from the original objects and the function results using the drop_conflicts strategy: matching attrs are kept, conflicting attrs are dropped. If False, the new dataset and variables will have only the attributes set by the function.

  • 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> Size: 64B
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 48B 1.764 0.4002 0.9787 2.241 1.868 -0.9773
    bar      (x) int64 16B -1 2
>>> ds.map(np.fabs)
<xarray.Dataset> Size: 64B
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 48B 1.764 0.4002 0.9787 2.241 1.868 0.9773
    bar      (x) float64 16B 1.0 2.0
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