.. _op_ai_onnx_Log:

Log
===

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

Computes the Log value of the input tensor element-wise.

**Inputs**

- **input** (*T*): Input tensor

**Outputs**

- **output** (*T*): The natural log of the input tensor computed element-wise

**Type Constraints**

- **T**: Constrain input and output types to float tensors.
  Allowed types: tensor(bfloat16), tensor(double), tensor(float), tensor(float16).

Examples
--------

**test_cc_log**

.. code-block:: text

    Node:
      Log(x) -> (y)

.. code-block:: text

    Inputs:
      x: shape=(2, 3), dtype=float32
        [[ 0.1,  0.5,  1. ],
         [ 2. ,  4. , 10. ]]

    Outputs:
      y: shape=(2, 3), dtype=float32
        [[-2.3025851, -0.6931472,  0.       ],
         [ 0.6931472,  1.3862944,  2.3025851]]

**test_cc_log_bfloat16**

.. code-block:: text

    Node:
      Log(x) -> (y)

.. code-block:: text

    Inputs:
      x: shape=(2, 3), dtype=bfloat16
        [[0.5, 1, 1.5],
         [2, 3, 4]]

    Outputs:
      y: shape=(2, 3), dtype=bfloat16
        [[-0.691406, 0, 0.40625],
         [0.691406, 1.10156, 1.38281]]

**test_cc_log_float16**

.. code-block:: text

    Node:
      Log(x) -> (y)

.. code-block:: text

    Inputs:
      x: shape=(2, 3), dtype=float16
        [[0.5, 1. , 1.5],
         [2. , 3. , 4. ]]

    Outputs:
      y: shape=(2, 3), dtype=float16
        [[-0.6934,  0.    ,  0.4055],
         [ 0.6934,  1.099 ,  1.387 ]]

**test_log**

.. code-block:: text

    Node:
      Log(x) -> (y)

.. code-block:: text

    Inputs:
      x: shape=(3, 4, 5), dtype=float32
        [[[0.5665626 , 0.7457828 , 0.9710038 , 0.44436023, 0.44426572],
          [0.7628954 , 0.8773497 , 0.5230682 , 0.2855097 , 0.79399765],
          [0.40414318, 0.60542136, 0.45493892, 0.53008   , 0.4359664 ],
          [0.16703598, 0.6453357 , 0.8153516 , 0.681706  , 0.88432556]],
        
         [[0.06596119, 0.08141565, 0.49588096, 0.12310988, 0.28691238],
          [0.04790218, 0.51552093, 0.7137718 , 0.04374927, 0.9977489 ],
          [0.5978532 , 0.58659613, 0.39717028, 0.43898773, 0.25327417],
          [0.5297584 , 0.5436718 , 0.74823636, 0.8180345 , 0.66857445]],
        
         [[0.8618293 , 0.70818025, 0.23636153, 0.6562365 , 0.86890996],
          [0.83933234, 0.32443425, 0.15918033, 0.89394003, 0.9126912 ],
          [0.3018573 , 0.13158594, 0.32568467, 0.94017494, 0.39366317],
          [0.08773183, 0.6070508 , 0.15547849, 0.95833313, 0.8756163 ]]]

    Outputs:
      y: shape=(3, 4, 5), dtype=float32
        [[[-5.6816769e-01, -2.9332089e-01, -2.9424928e-02, -8.1111974e-01,
           -8.1133240e-01],
          [-2.7063435e-01, -1.3084964e-01, -6.4804345e-01, -1.2534792e+00,
           -2.3067479e-01],
          [-9.0598607e-01, -5.0183058e-01, -7.8759211e-01, -6.3472730e-01,
           -8.3019012e-01],
          [-1.7895460e+00, -4.3798468e-01, -2.0413584e-01, -3.8315678e-01,
           -1.2293000e-01]],
        
         [[-2.7186887e+00, -2.5081878e+00, -7.0141935e-01, -2.0946779e+00,
           -1.2485784e+00],
          [-3.0385942e+00, -6.6257739e-01, -3.3719194e-01, -3.1292803e+00,
           -2.2536262e-03],
          [-5.1441008e-01, -5.3341872e-01, -9.2339021e-01, -8.2328379e-01,
           -1.3732827e+00],
          [-6.3533425e-01, -6.0940957e-01, -2.9003635e-01, -2.0085073e-01,
           -4.0260753e-01]],
        
         [[-1.4869808e-01, -3.4505662e-01, -1.4423927e+00, -4.2123398e-01,
           -1.4051577e-01],
          [-1.7514853e-01, -1.1256723e+00, -1.8377175e+00, -1.1211658e-01,
           -9.1357708e-02],
          [-1.1978009e+00, -2.0280950e+00, -1.1218257e+00, -6.1689317e-02,
           -9.3225962e-01],
          [-2.4334705e+00, -4.9914283e-01, -1.8612479e+00, -4.2559821e-02,
           -1.3282728e-01]]]

**test_log_example**

.. code-block:: text

    Node:
      Log(x) -> (y)

.. code-block:: text

    Inputs:
      x: shape=(2,), dtype=float32
        [ 1., 10.]

    Outputs:
      y: shape=(2,), dtype=float32
        [0.       , 2.3025851]

Differences with previous version (6)
-------------------------------------

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

* old version: 6
* new version: 13
* breaking: no

**Type constraints:**

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

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

- :doc:`Version 6 <Log-6>`
- :doc:`Version 1 <Log-1>`