(from_tensor, to_mask)
return mask
Create 3D attention mask from a 2D tensor mask.

  Args:
    from_tensor: 2D or 3D Tensor of shape [batch_size, from_seq_length, ...].
    to_mask: int32 Tensor of shape [batch_size, to_seq_length].

  Returns:
    float Tensor of shape [batch_size, from_seq_length, to_seq_length].
Create 3D attention mask from a 2D tensor mask.
Create 3D attention mask from a 2D tensor mask .
def create_attention_mask_from_input_mask(from_tensor, to_mask):
  """Create 3D attention mask from a 2D tensor mask.

  Args:
    from_tensor: 2D or 3D Tensor of shape [batch_size, from_seq_length, ...].
    to_mask: int32 Tensor of shape [batch_size, to_seq_length].

  Returns:
    float Tensor of shape [batch_size, from_seq_length, to_seq_length].
  """
  from_shape = get_shape_list(from_tensor, expected_rank=[2, 3])
  batch_size = from_shape[0]
  from_seq_length = from_shape[1]

  to_shape = get_shape_list(to_mask, expected_rank=2)
  to_seq_length = to_shape[1]

  to_mask = tf.cast(
      tf.reshape(to_mask, [batch_size, 1, to_seq_length]), tf.float32)

  # We don't assume that `from_tensor` is a mask (although it could be). We
  # don't actually care if we attend *from* padding tokens (only *to* padding)
  # tokens so we create a tensor of all ones.
  #
  # `broadcast_ones` = [batch_size, from_seq_length, 1]
  broadcast_ones = tf.ones(
      shape=[batch_size, from_seq_length, 1], dtype=tf.float32)

  # Here we broadcast along two dimensions to create the mask.
  mask = broadcast_ones * to_mask

  return mask
def create_attention_mask_from_input_mask ( from_tensor , to_mask ) : from_shape = get_shape_list ( from_tensor , expected_rank = [ 2 , 3 ] ) batch_size = from_shape [ 0 ] from_seq_length = from_shape [ 1 ] to_shape = get_shape_list ( to_mask , expected_rank = 2 ) to_seq_length = to_shape [ 1 ] to_mask = tf . cast ( tf . reshape ( to_mask , [ batch_size , 1 , to_seq_length ] ) , tf . float32 ) # We don't assume that `from_tensor` is a mask (although it could be). We # don't actually care if we attend *from* padding tokens (only *to* padding) # tokens so we create a tensor of all ones. # # `broadcast_ones` = [batch_size, from_seq_length, 1] broadcast_ones = tf . ones ( shape = [ batch_size , from_seq_length , 1 ] , dtype = tf . float32 ) # Here we broadcast along two dimensions to create the mask. mask = broadcast_ones * to_mask return mask