# tensorplay.nn.utils.rnn.invert_permutation

Source: https://www.tensorplay.cn/docs/generated/tensorplay.nn.utils.rnn.invert_permutation.html

# tensorplay.nn.utils.rnn.invert_permutation

tensorplay.nn.utils.rnn.invert_permutation(permutation: TensorBase | [None](https://docs.python.org/3/library/constants.html#None)) → TensorBase | [None](https://docs.python.org/3/library/constants.html#None)[[source]](../_modules/tensorplay/nn/utils/rnn.html#invert_permutation)

Returns the inverse of permutation.

This is useful for converting between sorted and unsorted indices in
a PackedSequence.

Parameters:

permutation (Tensor, optional) – a 1-D tensor of indices to invert