2 Copyright (C) 2008-2023 EDF R&D
4 This file is part of SALOME ADAO module.
6 This library is free software; you can redistribute it and/or
7 modify it under the terms of the GNU Lesser General Public
8 License as published by the Free Software Foundation; either
9 version 2.1 of the License, or (at your option) any later version.
11 This library is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 Lesser General Public License for more details.
16 You should have received a copy of the GNU Lesser General Public
17 License along with this library; if not, write to the Free Software
18 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 See http://www.salome-platform.org/ or email : webmaster.salome@opencascade.com
22 Author: Jean-Philippe Argaud, jean-philippe.argaud@edf.fr, EDF R&D
24 .. index:: single: TangentTest
25 .. _section_ref_algorithm_TangentTest:
27 Checking algorithm "*TangentTest*"
28 ----------------------------------
30 .. ------------------------------------ ..
31 .. include:: snippets/Header2Algo01.rst
33 This algorithm allows to check the quality of the tangent operator, by
34 calculating a residue with known theoretical properties.
36 One can observe the following residue, which is the comparison of increments
37 using the tangent linear operator:
39 .. math:: R(\alpha) = \frac{|| F(\mathbf{x}+\alpha*\mathbf{dx}) - F(\mathbf{x}) ||}{|| \alpha * TangentF_x * \mathbf{dx} ||}
41 which has to remain stable in :math:`1+O(\alpha)` until the calculation
44 When :math:`|R-1|/\alpha` is less or equal to a stable value when :math:`\alpha`
45 is varying, the tangent is valid, until the calculation precision is reached.
47 If :math:`|R-1|/\alpha` is really small, the calculation code :math:`F` is
48 almost linear or quasi-linear (which can be verified by the
49 :ref:`section_ref_algorithm_LinearityTest`), and the tangent is valid until the
50 calculation precision is reached.
52 One take :math:`\mathbf{dx}_0=Normal(0,\mathbf{x})` and
53 :math:`\mathbf{dx}=\alpha*\mathbf{dx}_0`. :math:`F` is the calculation code.
55 .. ------------------------------------ ..
56 .. include:: snippets/Header2Algo02.rst
58 .. include:: snippets/CheckingPoint.rst
60 .. include:: snippets/ObservationOperator.rst
62 .. ------------------------------------ ..
63 .. include:: snippets/Header2Algo03Chck.rst
65 .. include:: snippets/AmplitudeOfInitialDirection.rst
67 .. include:: snippets/AmplitudeOfTangentPerturbation.rst
69 .. include:: snippets/EpsilonMinimumExponent.rst
71 .. include:: snippets/InitialDirection.rst
73 .. include:: snippets/SetSeed.rst
75 StoreSupplementaryCalculations
76 .. index:: single: StoreSupplementaryCalculations
78 *List of names*. This list indicates the names of the supplementary
79 variables, that can be available during or at the end of the algorithm, if
80 they are initially required by the user. Their avalability involves,
81 potentially, costly calculations or memory consumptions. The default is then
82 a void list, none of these variables being calculated and stored by default
83 (excepted the unconditionnal variables). The possible names are in the
84 following list (the detailed description of each named variable is given in
85 the following part of this specific algorithmic documentation, in the
86 sub-section "*Information and variables available at the end of the
90 "SimulatedObservationAtCurrentState",
94 ``{"StoreSupplementaryCalculations":["CurrentState", "Residu"]}``
96 .. ------------------------------------ ..
97 .. include:: snippets/Header2Algo04.rst
99 .. include:: snippets/Residu.rst
101 .. ------------------------------------ ..
102 .. include:: snippets/Header2Algo05.rst
104 .. include:: snippets/CurrentState.rst
106 .. include:: snippets/Residu.rst
108 .. include:: snippets/SimulatedObservationAtCurrentState.rst
110 .. ------------------------------------ ..
111 .. _section_ref_algorithm_TangentTest_examples:
112 .. include:: snippets/Header2Algo06.rst
114 - :ref:`section_ref_algorithm_FunctionTest`
115 - :ref:`section_ref_algorithm_LinearityTest`
116 - :ref:`section_ref_algorithm_AdjointTest`
117 - :ref:`section_ref_algorithm_GradientTest`
118 - :ref:`section_ref_algorithm_LocalSensitivityTest`