def build_read_mask(self):
"""Creates a mask which allows us to attenuate subsequent read strengths.
This is exposed as it's own function so that it can be overridden to provide
alternate read adressing schemes.
Returns:
A tf.float32 tensor of shape [1, memory_size, memory_size]
"""
return common_layers.mask_pos_gt(self._memory_size, self._memory_size)
def get_read_mask(self, read_head_index):
"""Uses mask_pos_lt() instead of mask_pos_gt() to reverse read values.
Args:
read_head_index: Identifies which read head we're getting the mask for.
Returns:
A tf.float32 tensor of shape [1, 1, memory_size, memory_size].
"""
return tf.expand_dims(common_layers.mask_pos_gt(
self._memory_size, self._memory_size),
axis=0)
def get_read_mask(self, read_head_index):
if read_head_index == 0:
# Use the same read mask as the queue for the bottom of the deque.
return tf.expand_dims(
common_layers.mask_pos_gt(self._memory_size, self._memory_size),
axis=0)
elif read_head_index == 1:
# Use the same read mask as the stack for the top of the deque.
return tf.expand_dims(
common_layers.mask_pos_lt(self._memory_size, self._memory_size),
axis=0)
else:
raise ValueError("Read head index must be either 0 or 1 for deque.")
