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.. * Copyright 2021 Intel Corporation
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.. * Licensed under the Apache License, Version 2.0 (the "License");
.. * you may not use this file except in compliance with the License.
.. * You may obtain a copy of the License at
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.. *     http://www.apache.org/licenses/LICENSE-2.0
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.. * distributed under the License is distributed on an "AS IS" BASIS,
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.. * See the License for the specific language governing permissions and
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.. default-domain:: cpp

.. _api_sigmoid_kernel:

===================================
Sigmoid kernel
===================================

.. include::  ../../../includes/kernel-functions/sigmoid-kernel-introduction.rst

------------------------
Mathematical formulation
------------------------

Refer to :ref:`Developer Guide: Sigmoid kernel <alg_sigmoid_kernel>`.

---------------------
Programming Interface
---------------------
All types and functions in this section are declared in the
``oneapi::dal::sigmoid_kernel`` namespace and are available via inclusion of the
``oneapi/dal/algo/sigmoid_kernel.hpp`` header file.

Descriptor
----------
.. onedal_class:: oneapi::dal::sigmoid_kernel::descriptor

Method tags
~~~~~~~~~~~
.. onedal_tags_namespace:: oneapi::dal::sigmoid_kernel::method

Task tags
~~~~~~~~~
.. onedal_tags_namespace:: oneapi::dal::sigmoid_kernel::task

.. _sigmoid_kernel_c_api:

Training :expr:`compute(...)`
-----------------------------
.. _sigmoid_kernel_c_api_input:

Input
~~~~~
.. onedal_class:: oneapi::dal::sigmoid_kernel::compute_input


.. _sigmoid_kernel_c_api_result:

Result
~~~~~~
.. onedal_class:: oneapi::dal::sigmoid_kernel::compute_result

Operation
~~~~~~~~~
.. function:: template <typename Descriptor> \
              sigmoid_kernel::compute_result compute(const Descriptor& desc, \
                                      const sigmoid_kernel::compute_input& input)

   :param desc: Sigmoid Kernel algorithm descriptor :expr:`sigmoid_kernel::descriptor`
   :param input: Input data for the computing operation

   Preconditions
      | :expr:`input.x.is_empty == false`
      | :expr:`input.y.is_empty == false`
      | :expr:`input.x.column_count == input.y.column_count`
   Postconditions
      | :expr:`result.values.has_data == true`
      | :expr:`result.values.row_count == input.x.row_count`
      | :expr:`result.values.column_count == input.y.row_count`