2 Copyright (C) 2008-2018 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 ----------------------------------
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 Optional and required commands
56 ++++++++++++++++++++++++++++++
58 The general required commands, available in the editing user interface, are the
61 .. include:: snippets/CheckingPoint.rst
63 .. include:: snippets/ObservationOperator.rst
65 The general optional commands, available in the editing user interface, are
66 indicated in :ref:`section_ref_assimilation_keywords`. Moreover, the parameters
67 of the command "*AlgorithmParameters*" allow to choose the specific options,
68 described hereafter, of the algorithm. See
69 :ref:`section_ref_options_Algorithm_Parameters` for the good use of this
72 The options of the algorithm are the following:
74 .. include:: snippets/AmplitudeOfInitialDirection.rst
76 .. include:: snippets/EpsilonMinimumExponent.rst
78 .. include:: snippets/InitialDirection.rst
80 .. include:: snippets/SetSeed.rst
82 StoreSupplementaryCalculations
83 .. index:: single: StoreSupplementaryCalculations
85 This list indicates the names of the supplementary variables that can be
86 available at the end of the algorithm. It involves potentially costly
87 calculations or memory consumptions. The default is a void list, none of
88 these variables being calculated and stored by default. The possible names
89 are in the following list: ["CurrentState", "Residu",
90 "SimulatedObservationAtCurrentState"].
93 ``{"StoreSupplementaryCalculations":["CurrentState"]}``
95 Information and variables available at the end of the algorithm
96 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
98 At the output, after executing the algorithm, there are variables and
99 information originating from the calculation. The description of
100 :ref:`section_ref_output_variables` show the way to obtain them by the method
101 named ``get`` of the variable "*ADD*" of the post-processing. The input
102 variables, available to the user at the output in order to facilitate the
103 writing of post-processing procedures, are described in the
104 :ref:`subsection_r_o_v_Inventaire`.
106 The unconditional outputs of the algorithm are the following:
108 .. include:: snippets/Residu.rst
110 The conditional outputs of the algorithm are the following:
112 .. include:: snippets/CurrentState.rst
114 .. include:: snippets/SimulatedObservationAtCurrentState.rst
119 References to other sections:
120 - :ref:`section_ref_algorithm_FunctionTest`
121 - :ref:`section_ref_algorithm_LinearityTest`
122 - :ref:`section_ref_algorithm_AdjointTest`
123 - :ref:`section_ref_algorithm_GradientTest`