o ¡¿¯i÷ã@sdZdd„ZdS)z!Create mask for subsequent steps.cCsF|j\}}| |¡}|d|dd…dfkd}| ||||f¡}|S)zµPrepare the history mask. Args: block (ndarray): Block with dimensions: (B x S). Returns: ndarray, np.ndarray: History mask with dimensions (B, S, S). N)N)ÚshapeÚarangeÚ broadcast_to)ÚxpÚblockÚbatchÚlengthrÚ history_mask©r ú`/home/ubuntu/.local/lib/python3.10/site-packages/espnet/nets/chainer_backend/transformer/mask.pyÚmake_history_masks ÿr N)Ú__doc__r r r r r Ús