# xarray.Dataset.to_stacked_array

`Dataset.``to_stacked_array`(new_dim: Hashable, sample_dims: Sequence[Hashable], variable_dim: str = 'variable', name: Hashable = None) → DataArray

  Combine variables of differing dimensionality into a DataArray without broadcasting.

  This method is similar to Dataset.to_array but does not broadcast the variables.

  Parameters:

  - new_dim (Hashable) – Name of the new stacked coordinate
  - sample_dims (Sequence[Hashable]) – Dimensions that will not be stacked. Each array in the dataset must share these dimensions. For machine learning applications, these define the dimensions over which samples are drawn.
  - variable_dim (str, optional) – Name of the level in the stacked coordinate which corresponds to the variables.
  - name (str, optional) – Name of the new data array.

  Returns: | stacked – DataArray with the specified dimensions and data variables stacked together. The stacked coordinate is named `new_dim` and represented by a MultiIndex object with a level containing the data variable names. The name of this level is controlled using the `variable_dim` argument.
  Return type: | DataArray

  See also

  `Dataset.to_array()`, `Dataset.stack()`, `DataArray.to_unstacked_dataset()`

  Examples

      >>> data = Dataset(
      ...     data_vars={'a': (('x', 'y'), [[0, 1, 2], [3, 4, 5]]),
      ...                'b': ('x', [6, 7])},
      ...     coords={'y': ['u', 'v', 'w']}
      ... )

      >>> data
      <xarray.Dataset>
      Dimensions:  (x: 2, y: 3)
      Coordinates:
      * y        (y) <U1 'u' 'v' 'w'
      Dimensions without coordinates: x
      Data variables:
          a        (x, y) int64 0 1 2 3 4 5
          b        (x) int64 6 7

      >>> data.to_stacked_array("z", sample_dims=['x'])
      <xarray.DataArray (x: 2, z: 4)>
      array([[0, 1, 2, 6],
          [3, 4, 5, 7]])
      Coordinates:
      * z         (z) MultiIndex
      - variable  (z) object 'a' 'a' 'a' 'b'
      - y         (z) object 'u' 'v' 'w' nan
      Dimensions without coordinates: x