torch.nn.utils.clip_grad_norm_(parameters: Union[torch.Tensor, Iterable[torch.Tensor]], max_norm: float, norm_type: float = 2.0) → torch.Tensor[source]

Clips gradient norm of an iterable of parameters.

The norm is computed over all gradients together, as if they were concatenated into a single vector. Gradients are modified in-place.

Parameters
• parameters (Iterable[Tensor] or Tensor) – an iterable of Tensors or a single Tensor that will have gradients normalized

• max_norm (float or int) – max norm of the gradients

• norm_type (float or int) – type of the used p-norm. Can be 'inf' for infinity norm.

Returns

Total norm of the parameters (viewed as a single vector).