:nosearch:

.. _op_ai_onnx_Gather-11:

Gather - version 11
===================

This page documents version **11** of operator **Gather**. See :doc:`Gather` for the latest version (since version 13).

- **Domain**: ``ai.onnx``
- **Since version**: 11

Given ``data`` tensor of rank r >= 1, and ``indices`` tensor of rank q, gather
entries of the axis dimension of ``data`` (by default outer-most one as axis=0) indexed by ``indices``, and concatenates
them in an output tensor of rank q + (r - 1).

axis = 0 :

Let
k = indices[i{0}, ..., i{q-1}]
Then
output[i{0}, ..., i{q-1}, j{0}, ..., j{r-2}] = input[k , j{0}, ..., j{r-2}]

.. code-block::

      data = [
          [1.0, 1.2],
          [2.3, 3.4],
          [4.5, 5.7],
      ]
      indices = [
          [0, 1],
          [1, 2],
      ]
      output = [
          [
              [1.0, 1.2],
              [2.3, 3.4],
          ],
          [
              [2.3, 3.4],
              [4.5, 5.7],
          ],
      ]

axis = 1 :

Let
k = indices[i{0}, ..., i{q-1}]
Then
output[j{0}, i{0}, ..., i{q-1}, j{1}, ..., j{r-2}] = input[j{0}, k, j{1}, ..., j{r-2}]

.. code-block::

      data = [
          [1.0, 1.2, 1.9],
          [2.3, 3.4, 3.9],
          [4.5, 5.7, 5.9],
      ]
      indices = [
          [0, 2],
      ]
      axis = 1,
      output = [
          [[1.0, 1.9]],
          [[2.3, 3.9]],
          [[4.5, 5.9]],
      ]


**Inputs**

- **data** (*T*): Tensor of rank r >= 1.
- **indices** (*Tind*): Tensor of int32/int64 indices, of any rank q. All index values are expected to be within bounds [-s, s-1] along axis of size s. It is an error if any of the index values are out of bounds.

**Outputs**

- **output** (*T*): Tensor of rank q + (r - 1).

**Attributes**

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

**Type Constraints**

- **T**: Constrain input and output types to any tensor type.
  Allowed types: 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).
- **Tind**: Constrain indices to integer types
  Allowed types: tensor(int32), tensor(int64).

Differences with previous version (1)
-------------------------------------

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

* old version: 1
* new version: 11
* breaking: no

**Documentation:**

* line similarity: 0.83 (+15/-2 lines)

.. code-block:: diff

    --- Gather v1
    +++ Gather v11
    @@ -2,7 +2,14 @@
     Given `data` tensor of rank r >= 1, and `indices` tensor of rank q, gather
     entries of the axis dimension of `data` (by default outer-most one as axis=0) indexed by `indices`, and concatenates
     them in an output tensor of rank q + (r - 1).
    -Example 1:
    +
    +axis = 0 :
    +
    +Let
    +k = indices[i_{0}, ..., i_{q-1}]
    +Then
    +output[i_{0}, ..., i_{q-1}, j_{0}, ..., j_{r-2}] = input[k , j_{0}, ..., j_{r-2}]
    +
     ```
       data = [
           [1.0, 1.2],
    @@ -24,7 +31,13 @@
           ],
       ]
     ```
    -Example 2:
    +axis = 1 :
    +
    +Let
    +k = indices[i_{0}, ..., i_{q-1}]
    +Then
    +output[j_{0}, i_{0}, ..., i_{q-1}, j_{1}, ..., j_{r-2}] = input[j_{0}, k, j_{1}, ..., j_{r-2}]
    +
     ```
       data = [
           [1.0, 1.2, 1.9],