ReverseSequence#
ReverseSequence - 10#
Version
name: ReverseSequence (GitHub)
domain: main
since_version: 10
function: False
support_level: SupportType.COMMON
shape inference: True
This version of the operator has been available since version 10.
Summary
Reverse batch of sequences having different lengths specified by sequence_lens.
For each slice i iterating on batch axis, the operator reverses the first sequence_lens[i] elements on time axis, and copies elements whose index’s beyond sequence_lens[i] to the output. So the output slice i contains reversed sequences on the first sequence_lens[i] elements, then have original values copied for the other elements.
- Example 1:
- input = [[0.0, 4.0, 8.0, 12.0],
[1.0, 5.0, 9.0, 13.0], [2.0, 6.0, 10.0, 14.0], [3.0, 7.0, 11.0, 15.0]]
sequence_lens = [4, 3, 2, 1] time_axis = 0 batch_axis = 1
- output = [[3.0, 6.0, 9.0, 12.0],
[2.0, 5.0, 8.0, 13.0], [1.0, 4.0, 10.0, 14.0], [0.0, 7.0, 11.0, 15.0]]
- Example 2:
- input = [[0.0, 1.0, 2.0, 3.0 ],
[4.0, 5.0, 6.0, 7.0 ], [8.0, 9.0, 10.0, 11.0], [12.0, 13.0, 14.0, 15.0]]
sequence_lens = [1, 2, 3, 4] time_axis = 1 batch_axis = 0
- output = [[0.0, 1.0, 2.0, 3.0 ],
[5.0, 4.0, 6.0, 7.0 ], [10.0, 9.0, 8.0, 11.0], [15.0, 14.0, 13.0, 12.0]]
Attributes
batch_axis: (Optional) Specify which axis is batch axis. Must be one of 1 (default), or 0. Default value is
1
.time_axis: (Optional) Specify which axis is time axis. Must be one of 0 (default), or 1. Default value is
0
.
Inputs
input (heterogeneous) - T: Tensor of rank r >= 2.
sequence_lens (heterogeneous) - tensor(int64): Tensor specifying lengths of the sequences in a batch. It has shape [batch_size].
Outputs
Y (heterogeneous) - T: Tensor with same shape of input.
Type Constraints
T in ( tensor(bool), tensor(complex128), tensor(complex64), tensor(double), tensor(float), tensor(float16), tensor(int16), tensor(int32), tensor(int64), tensor(int8), tensor(string), tensor(uint16), tensor(uint32), tensor(uint64), tensor(uint8) ): Input and output types can be of any tensor type.
Examples
reversesequence_time
node = onnx.helper.make_node(
'ReverseSequence',
inputs=['x', 'sequence_lens'],
outputs=['y'],
time_axis=0,
batch_axis=1,
)
x = np.array([[0.0, 4.0, 8.0, 12.0],
[1.0, 5.0, 9.0, 13.0],
[2.0, 6.0, 10.0, 14.0],
[3.0, 7.0, 11.0, 15.0]], dtype=np.float32)
sequence_lens = np.array([4, 3, 2, 1], dtype=np.int64)
y = np.array([[3.0, 6.0, 9.0, 12.0],
[2.0, 5.0, 8.0, 13.0],
[1.0, 4.0, 10.0, 14.0],
[0.0, 7.0, 11.0, 15.0]], dtype=np.float32)
expect(node, inputs=[x, sequence_lens], outputs=[y],
name='test_reversesequence_time')
reversesequence_batch
node = onnx.helper.make_node(
'ReverseSequence',
inputs=['x', 'sequence_lens'],
outputs=['y'],
time_axis=1,
batch_axis=0,
)
x = np.array([[0.0, 1.0, 2.0, 3.0],
[4.0, 5.0, 6.0, 7.0],
[8.0, 9.0, 10.0, 11.0],
[12.0, 13.0, 14.0, 15.0]], dtype=np.float32)
sequence_lens = np.array([1, 2, 3, 4], dtype=np.int64)
y = np.array([[0.0, 1.0, 2.0, 3.0],
[5.0, 4.0, 6.0, 7.0],
[10.0, 9.0, 8.0, 11.0],
[15.0, 14.0, 13.0, 12.0]], dtype=np.float32)
expect(node, inputs=[x, sequence_lens], outputs=[y],
name='test_reversesequence_batch')