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.. _implicit_als_batch_computation:

Batch Processing
================

Training
********

For a description of the input and output, refer to :ref:`recommendation_system_usage_model`.

At the training stage, the implicit ALS recommender has the following parameters:

.. tabularcolumns::  |\Y{0.15}|\Y{0.15}|\Y{0.7}|

.. list-table:: Training Parameters for Implicit Alternating Least Squares Computation (Batch Processing)
   :widths: 10 10 60
   :header-rows: 1
   :align: left
   :class: longtable

   * - Parameter
     - Default Value
     - Description
   * - ``algorithmFPType``
     - ``float``
     - The floating-point type that the algorithm uses for intermediate computations. Can be ``float`` or ``double``.
   * - ``method``
     - ``defaultDense``
     - Available computation methods:

       + ``defaultDense`` - performance-oriented method
       + ``fastCSR`` - performance-oriented method for CSR numeric tables

   * - ``nFactors``
     - :math:`10`
     - The total number of factors.
   * - ``maxIterations``
     - :math:`5`
     - The number of iterations.
   * - ``alpha``
     - :math:`40`
     - The rate of confidence.
   * - ``lambda``
     - :math:`0.01`
     - The parameter of the regularization.
   * - ``preferenceThreshold``
     - :math:`0`
     - Threshold used to define preference values. :math:`0` is the only threshold supported so far.

Prediction
**********

For a description of the input and output, refer to :ref:`recommendation_system_usage_model`.

At the prediction stage, the implicit ALS recommender has the following parameters:

.. tabularcolumns::  |\Y{0.15}|\Y{0.15}|\Y{0.7}|

.. list-table:: Prediction Parameters for Implicit Alternating Least Squares Computation (Batch Processing)
   :widths: 10 10 60
   :header-rows: 1
   :align: left
   :class: longtable

   * - Parameter
     - Default Value
     - Description
   * - ``algorithmFPType``
     - ``float``
     - The floating-point type that the algorithm uses for intermediate computations. Can be ``float`` or ``double``.
   * - ``method``
     - ``defaultDense``
     - Performance-oriented computation method, the only method supported by the algorithm.