flax.linen.logical_to_mesh_axes(array_dim_names, rules=None)[source]#

Compute layout for an array.

The rules are in order of precedence, and consist of pairs: (ArrayDimensionName, MeshDimensionName), meaning that the given array dimension (if present and unused) should be sharded across the given mesh dimension (if present and unused).

A Layout of an Array is expressed as a tuple with one element for each dimension in the Array. The element is either None, or is the name of a mesh-dimension, meaning that this dimension of the array is sharded across this dimension of the mesh.

For example, given an array with

array_dim_names = (‘batch’, ‘length’, ‘heads’, ‘features’)

and the layout rules are:
rules = ((‘batch’, ‘X’),

(‘features’, ‘X’), (‘heads’, ‘Y’), (‘batch’, ‘Z’))

then this function will return

PartitionSpec(‘X’, None, ‘Y’, None)

  • array_dim_names – Tuple of array dimension names or None.

  • rules – Optional logical to mesh rules override. Defaults to using the rules defined in the dynamic context set from the axis_rules function.


PartitionSpec for the parameter.