xarray.DataArray.dot#

DataArray.dot(other, dim=None)[source]#

Perform dot product of two DataArrays along their shared dims.

Equivalent to taking taking tensordot over all shared dims.

Parameters:

  • other (DataArray) – The other array with which the dot product is performed.

  • dim (..., str, Iterable of Hashable or None, optional) – Which dimensions to sum over. Ellipsis (…) sums over all dimensions. If not specified, then all the common dimensions are summed over.

Returns:

result (DataArray) – Array resulting from the dot product over all shared dimensions.

See also

dot, numpy.tensordot

Notes

This method automatically aligns coordinates by their values (not their order). See Automatic alignment and xarray.dot() for more details.

Examples

>>> da_vals = np.arange(6 * 5 * 4).reshape((6, 5, 4))
>>> da = xr.DataArray(da_vals, dims=["x", "y", "z"])
>>> dm_vals = np.arange(4)
>>> dm = xr.DataArray(dm_vals, dims=["z"])

>>> dm.dims
('z',)

>>> da.dims
('x', 'y', 'z')

>>> dot_result = da.dot(dm)
>>> dot_result.dims
('x', 'y')

Coordinates are aligned by their values:

>>> x = xr.DataArray([1, 10], coords=[("foo", ["a", "b"])])
>>> y = xr.DataArray([2, 20], coords=[("foo", ["b", "a"])])
>>> x.dot(y)
<xarray.DataArray ()> Size: 8B
array(40)
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