.. Copyright 2021 IRT Saint Exupéry, https://www.irt-saintexupery.com This work is licensed under the Creative Commons Attribution-ShareAlike 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by-sa/4.0/ or send a letter to Creative Commons, PO Box 1866, Mountain View, CA 94042, USA. .. Contributors: :author: Matthias De Lozzo :parenttoc: True .. _surrogates: Surrogate models ---------------- When an :class:`.MDODiscipline` is costly to evaluate, it can be replaced by a :class:`.SurrogateDiscipline` cheap to evaluate, e.g. linear model, Kriging, RBF regressor, ... This :class:`.SurrogateDiscipline` is built from a few evaluations of this :class:`.MDODiscipline`. This learning phase commonly relies on a regression model calibrated by machine learning techniques. This is the reason why |g| provides a machine learning package which includes the :class:`.MLRegressionAlgo` class implementing the concept of regression model. In addition, this machine learning package has a much broader set of features than regression: clustering, classification, dimension reduction, data scaling, ... .. seealso:: :ref:`mlearning` .. include:: includes/big_toc_css.rst .. include:: tune_toc.rst .. toctree:: :maxdepth: 2 examples/surrogate/plot_surrogate_discipline.rst