megengine.functional.distributed.scatter¶
- scatter(inp, group=WORLD, device=None, axis=0)[source]¶
Split tensor in root process at first dimension.
- Parameters
inp (
Tensor) – Input tensor.group (
Optional[Group]) – The process group to work on. The default group is WORLD which means all processes available. You can use a list of process ranks to create new group to work on it, e.g. [1, 3, 5].device (
Optional[str]) – The specific device to execute this operator. None default device means the device of inp will be used. Specify “gpu0:1” to execute this operator on diffrent cuda stream, 1 is stream id, and default stream id is 0.axis – The concat axis for collective_comm result The default axis is 0
- Return type
- Returns
Split tensor.
Examples
input = Tensor([0 1]) + rank*2 # Rank 0 # input: Tensor([0 1]) # Rank 1 # input: Tensor([2 3]) output = scatter(input) # Rank 0 # output: Tensor([0]) # Rank 1 # output: Tensor([1]) input = Tensor([0 1]) + rank*2 group = Group([1, 0]) # first rank is root output = scatter(input, group) # Rank 0 # output: Tensor([3]) # Rank 1 # output: Tensor([2])