:nosearch:

.. _op_ai_onnx_Split-13:

Split - version 13
==================

This page documents version **13** of operator **Split**. See :doc:`Split` for the latest version (since version 18).

- **Domain**: ``ai.onnx``
- **Since version**: 13

Split a tensor into a list of tensors, along the specified
'axis'. Lengths of the parts can be specified using input 'split'.
Otherwise, the tensor is split to equal sized parts.

**Inputs**

- **input** (*T*): The tensor to split
- **split** (*tensor(int64)*): Optional length of each output. Values should be >= 0.Sum of the values must be equal to the dim value at 'axis' specified.

**Outputs**

Between 1 and ∞ outputs.

- **outputs** (*T*): One or more outputs forming list of tensors after splitting

**Attributes**

- **axis** (*int*): Which axis to split on. A negative value means counting dimensions from the back. Accepted range is [-rank, rank-1] where r = rank(input).

**Type Constraints**

- **T**: Constrain input and output types to all tensor types.
  Allowed types: tensor(bfloat16), 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).

Examples
--------

**test_cc_split_equal_parts_1d_opset13**

.. code-block:: text

    Node:
      Split(input) -> (output_1, output_2, output_3)
      Attributes:
        axis = 0

.. code-block:: text

    Inputs:
      input: shape=(6,), dtype=float32
        [1., 2., 3., 4., 5., 6.]

    Outputs:
      output_1: shape=(2,), dtype=float32
        [1., 2.]
      output_2: shape=(2,), dtype=float32
        [3., 4.]
      output_3: shape=(2,), dtype=float32
        [5., 6.]

**test_cc_split_equal_parts_2d_opset13**

.. code-block:: text

    Node:
      Split(input) -> (output_1, output_2)
      Attributes:
        axis = 1

.. code-block:: text

    Inputs:
      input: shape=(2, 6), dtype=float32
        [[ 1.,  2.,  3.,  4.,  5.,  6.],
         [ 7.,  8.,  9., 10., 11., 12.]]

    Outputs:
      output_1: shape=(2, 3), dtype=float32
        [[1., 2., 3.],
         [7., 8., 9.]]
      output_2: shape=(2, 3), dtype=float32
        [[ 4.,  5.,  6.],
         [10., 11., 12.]]

**test_cc_split_equal_parts_default_axis_opset13**

.. code-block:: text

    Node:
      Split(input) -> (output_1, output_2, output_3)

.. code-block:: text

    Inputs:
      input: shape=(6,), dtype=float32
        [1., 2., 3., 4., 5., 6.]

    Outputs:
      output_1: shape=(2,), dtype=float32
        [1., 2.]
      output_2: shape=(2,), dtype=float32
        [3., 4.]
      output_3: shape=(2,), dtype=float32
        [5., 6.]

**test_cc_split_variable_parts_1d_opset13**

.. code-block:: text

    Node:
      Split(input, split) -> (output_1, output_2)
      Attributes:
        axis = 0

.. code-block:: text

    Inputs:
      input: shape=(6,), dtype=float32
        [1., 2., 3., 4., 5., 6.]
      split: shape=(2,), dtype=int64
        [2, 4]

    Outputs:
      output_1: shape=(2,), dtype=float32
        [1., 2.]
      output_2: shape=(4,), dtype=float32
        [3., 4., 5., 6.]

**test_cc_split_variable_parts_2d_opset13**

.. code-block:: text

    Node:
      Split(input, split) -> (output_1, output_2)
      Attributes:
        axis = 1

.. code-block:: text

    Inputs:
      input: shape=(2, 6), dtype=float32
        [[ 1.,  2.,  3.,  4.,  5.,  6.],
         [ 7.,  8.,  9., 10., 11., 12.]]
      split: shape=(2,), dtype=int64
        [2, 4]

    Outputs:
      output_1: shape=(2, 2), dtype=float32
        [[1., 2.],
         [7., 8.]]
      output_2: shape=(2, 4), dtype=float32
        [[ 3.,  4.,  5.,  6.],
         [ 9., 10., 11., 12.]]

**test_cc_split_variable_parts_default_axis_opset13**

.. code-block:: text

    Node:
      Split(input, split) -> (output_1, output_2)

.. code-block:: text

    Inputs:
      input: shape=(6,), dtype=float32
        [1., 2., 3., 4., 5., 6.]
      split: shape=(2,), dtype=int64
        [2, 4]

    Outputs:
      output_1: shape=(2,), dtype=float32
        [1., 2.]
      output_2: shape=(4,), dtype=float32
        [3., 4., 5., 6.]

**test_cc_split_zero_size_splits_opset13**

.. code-block:: text

    Node:
      Split(input, split) -> (output_1, output_2, output_3)

.. code-block:: text

    Inputs:
      input: shape=(0,), dtype=float32
        []
      split: shape=(3,), dtype=int64
        [0, 0, 0]

    Outputs:
      output_1: shape=(0,), dtype=float32
        []
      output_2: shape=(0,), dtype=float32
        []
      output_3: shape=(0,), dtype=float32
        []

Differences with previous version (11)
--------------------------------------

**SchemaDiff**: ``Split`` (domain ``'ai.onnx'``)

* old version: 11
* new version: 13
* breaking: **yes**

**Breaking reasons:**

* input 'split' (added): at position 1; option=Single; type_str='tensor(int64)'
* attribute 'split' (removed): type=INTS; required=False

**Inputs:**

* [BREAKING] added 'split': at position 1; option=Single; type_str='tensor(int64)'

**Attributes:**

* [BREAKING] removed 'split': type=INTS; required=False

**Type constraints:**

* changed 'T': added types: ['tensor(bfloat16)']

**Documentation:**

* line similarity: 0.67 (+1/-1 lines)

.. code-block:: diff

    --- Split v11
    +++ Split v13
    @@ -1,3 +1,3 @@
     Split a tensor into a list of tensors, along the specified
    -'axis'. Lengths of the parts can be specified using argument 'split'.
    +'axis'. Lengths of the parts can be specified using input 'split'.
     Otherwise, the tensor is split to equal sized parts.