.. _op_ai_onnx_IsNaN:

IsNaN
=====

- **Domain**: ``ai.onnx``
- **Since version**: 20

Returns which elements of the input are NaN.

**Inputs**

- **X** (*T1*): input

**Outputs**

- **Y** (*T2*): output

**Type Constraints**

- **T1**: Constrain input types to float tensors.
  Allowed types: tensor(bfloat16), tensor(double), tensor(float), tensor(float16), tensor(float8e4m3fn), tensor(float8e4m3fnuz), tensor(float8e5m2), tensor(float8e5m2fnuz).
- **T2**: Constrain output types to boolean tensors.
  Allowed types: tensor(bool).

Examples
--------

**test_cc_isnan**

.. code-block:: text

    Node:
      IsNaN(x) -> (y)

.. code-block:: text

    Inputs:
      x: shape=(3,), dtype=float32
        [ 1., nan,  2.]

    Outputs:
      y: shape=(3,), dtype=bool
        [False,  True, False]

**test_cc_isnan_bfloat16**

.. code-block:: text

    Node:
      IsNaN(x) -> (y)

.. code-block:: text

    Inputs:
      x: shape=(6,), dtype=bfloat16
        [-1.20312, nan, inf, 2.79688, -inf, inf]

    Outputs:
      y: shape=(6,), dtype=bool
        [False,  True, False, False, False, False]

**test_cc_isnan_double**

.. code-block:: text

    Node:
      IsNaN(x) -> (y)

.. code-block:: text

    Inputs:
      x: shape=(6,), dtype=float64
        [-1.2,  nan,  inf,  2.8, -inf,  nan]

    Outputs:
      y: shape=(6,), dtype=bool
        [False,  True, False, False, False,  True]

**test_isnan**

.. code-block:: text

    Node:
      IsNaN(x) -> (y)

.. code-block:: text

    Inputs:
      x: shape=(6,), dtype=float32
        [-1.2,  nan,  inf,  2.8, -inf,  inf]

    Outputs:
      y: shape=(6,), dtype=bool
        [False,  True, False, False, False, False]

**test_isnan_float16**

.. code-block:: text

    Node:
      IsNaN(x) -> (y)

.. code-block:: text

    Inputs:
      x: shape=(6,), dtype=float16
        [-1.2,  nan,  inf,  2.8, -inf,  inf]

    Outputs:
      y: shape=(6,), dtype=bool
        [False,  True, False, False, False, False]

Differences with previous version (13)
--------------------------------------

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

* old version: 13
* new version: 20
* breaking: no

**Type constraints:**

* changed 'T1': added types: ['tensor(float8e4m3fn)', 'tensor(float8e4m3fnuz)', 'tensor(float8e5m2)', 'tensor(float8e5m2fnuz)']

Version History
---------------

- :doc:`Version 13 <IsNaN-13>`
- :doc:`Version 9 <IsNaN-9>`