2 Copyright (C) 2008-2024 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 whose theoretical properties are known. The test is
35 applicable to any operator, of evolution :math:`\mathcal{D}` or observation
38 For all formulas, with :math:`\mathbf{x}` the current verification point, we
39 take :math:`\mathbf{dx}_0=Normal(0,\mathbf{x})` and
40 :math:`\mathbf{dx}=\alpha_0*\mathbf{dx}_0` with :math:`\alpha_0` a scaling user
41 parameter, defaulting to 1. :math:`F` is the computational operator or code
42 (which is here defined by the observation operator command
43 "*ObservationOperator*").
45 One can observe the following residue, which is the comparison of increments
46 using the tangent linear operator:
48 .. math:: R(\alpha) = \frac{|| F(\mathbf{x}+\alpha*\mathbf{dx}) - F(\mathbf{x}) ||}{|| \alpha * TangentF_x * \mathbf{dx} ||}
50 which has to remain stable in :math:`1+O(\alpha)` until the calculation
53 When :math:`|R-1|/\alpha` is less or equal to a stable value when :math:`\alpha`
54 is varying, the tangent is valid, until the calculation precision is reached.
56 If :math:`|R-1|/\alpha` is really small, the calculation code :math:`F` is
57 almost linear or quasi-linear (which can be verified by the
58 :ref:`section_ref_algorithm_LinearityTest`), and the tangent is valid until the
59 calculation precision is reached.
61 .. ------------------------------------ ..
62 .. include:: snippets/Header2Algo12.rst
64 .. include:: snippets/FeaturePropDerivativeNeeded.rst
66 .. ------------------------------------ ..
67 .. include:: snippets/Header2Algo02.rst
69 .. include:: snippets/CheckingPoint.rst
71 .. include:: snippets/ObservationOperator.rst
73 .. ------------------------------------ ..
74 .. include:: snippets/Header2Algo03Chck.rst
76 .. include:: snippets/AmplitudeOfInitialDirection.rst
78 .. include:: snippets/AmplitudeOfTangentPerturbation.rst
80 .. include:: snippets/EpsilonMinimumExponent.rst
82 .. include:: snippets/InitialDirection.rst
84 .. include:: snippets/NumberOfPrintedDigits.rst
86 .. include:: snippets/SetSeed.rst
88 StoreSupplementaryCalculations
89 .. index:: single: StoreSupplementaryCalculations
91 *List of names*. This list indicates the names of the supplementary
92 variables, that can be available during or at the end of the algorithm, if
93 they are initially required by the user. Their availability involves,
94 potentially, costly calculations or memory consumptions. The default is then
95 a void list, none of these variables being calculated and stored by default
96 (excepted the unconditional variables). The possible names are in the
97 following list (the detailed description of each named variable is given in
98 the following part of this specific algorithmic documentation, in the
99 sub-section "*Information and variables available at the end of the
103 "SimulatedObservationAtCurrentState",
107 ``{"StoreSupplementaryCalculations":["CurrentState", "Residu"]}``
109 .. ------------------------------------ ..
110 .. include:: snippets/Header2Algo04.rst
112 .. include:: snippets/Residu.rst
114 .. ------------------------------------ ..
115 .. include:: snippets/Header2Algo05.rst
117 .. include:: snippets/CurrentState.rst
119 .. include:: snippets/Residu.rst
121 .. include:: snippets/SimulatedObservationAtCurrentState.rst
123 .. ------------------------------------ ..
124 .. _section_ref_algorithm_TangentTest_examples:
126 .. include:: snippets/Header2Algo06.rst
128 - :ref:`section_ref_algorithm_FunctionTest`
129 - :ref:`section_ref_algorithm_LinearityTest`
130 - :ref:`section_ref_algorithm_AdjointTest`
131 - :ref:`section_ref_algorithm_GradientTest`
132 - :ref:`section_ref_algorithm_LocalSensitivityTest`