2 Copyright (C) 2008-2021 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: 4DVAR
25 .. index:: single: 4D-Var
26 .. _section_ref_algorithm_4DVAR:
28 Algorithme de calcul "*4DVAR*"
29 ------------------------------
31 .. ------------------------------------ ..
32 .. include:: snippets/Header2Algo00.rst
34 .. ------------------------------------ ..
35 .. include:: snippets/Header2Algo01.rst
37 Cet algorithme réalise une estimation de l'état d'un système dynamique, par une
38 méthode de minimisation variationnelle de la fonctionnelle :math:`J` d'écart
39 classique en assimilation de données :
41 .. math:: J(\mathbf{x})=(\mathbf{x}-\mathbf{x}^b)^T.\mathbf{B}^{-1}.(\mathbf{x}-\mathbf{x}^b)+\sum_{t\in T}(\mathbf{y^o}(t)-H(\mathbf{x},t))^T.\mathbf{R}^{-1}.(\mathbf{y^o}(t)-H(\mathbf{x},t))
43 qui est usuellement désignée comme la fonctionnelle "*4D-Var*" (voir par
44 exemple [Talagrand97]_). Les dénominations "*4D-Var*", "*4D-VAR*" et "*4DVAR*"
45 sont équivalentes. Il est bien adapté aux cas d'opérateurs d'observation et
46 d'évolution non-linéaires, son domaine d'application est comparable aux
47 algorithmes de filtrage de Kalman et en particulier
48 l':ref:`section_ref_algorithm_ExtendedKalmanFilter` ou
49 l':ref:`section_ref_algorithm_UnscentedKalmanFilter`.
51 .. ------------------------------------ ..
52 .. include:: snippets/Header2Algo02.rst
54 .. include:: snippets/Background.rst
56 .. include:: snippets/BackgroundError.rst
58 .. include:: snippets/EvolutionError.rst
60 .. include:: snippets/EvolutionModel.rst
62 .. include:: snippets/Observation.rst
64 .. include:: snippets/ObservationError.rst
66 .. include:: snippets/ObservationOperator.rst
68 .. ------------------------------------ ..
69 .. include:: snippets/Header2Algo03AdOp.rst
71 .. include:: snippets/BoundsWithNone.rst
73 .. include:: snippets/ConstrainedBy.rst
75 .. include:: snippets/CostDecrementTolerance.rst
77 .. include:: snippets/EstimationOf.rst
79 .. include:: snippets/GradientNormTolerance.rst
81 .. include:: snippets/InitializationPoint.rst
83 .. include:: snippets/MaximumNumberOfSteps.rst
85 .. include:: snippets/Minimizer_xDVAR.rst
87 .. include:: snippets/ProjectedGradientTolerance.rst
89 StoreSupplementaryCalculations
90 .. index:: single: StoreSupplementaryCalculations
92 *Liste de noms*. Cette liste indique les noms des variables supplémentaires
93 qui peuvent être disponibles au cours du déroulement ou à la fin de
94 l'algorithme, si elles sont initialement demandées par l'utilisateur. Cela
95 implique potentiellement des calculs ou du stockage coûteux. La valeur par
96 défaut est une liste vide, aucune de ces variables n'étant calculée et
97 stockée par défaut sauf les variables inconditionnelles. Les noms possibles
98 sont dans la liste suivante : [
102 "CostFunctionJAtCurrentOptimum",
104 "CostFunctionJbAtCurrentOptimum",
106 "CostFunctionJoAtCurrentOptimum",
107 "CurrentIterationNumber",
114 ``{"StoreSupplementaryCalculations":["BMA", "CurrentState"]}``
116 .. ------------------------------------ ..
117 .. include:: snippets/Header2Algo04.rst
119 .. include:: snippets/Analysis.rst
121 .. include:: snippets/CostFunctionJ.rst
123 .. include:: snippets/CostFunctionJb.rst
125 .. include:: snippets/CostFunctionJo.rst
127 .. ------------------------------------ ..
128 .. include:: snippets/Header2Algo05.rst
130 .. include:: snippets/Analysis.rst
132 .. include:: snippets/BMA.rst
134 .. include:: snippets/CostFunctionJ.rst
136 .. include:: snippets/CostFunctionJAtCurrentOptimum.rst
138 .. include:: snippets/CostFunctionJb.rst
140 .. include:: snippets/CostFunctionJbAtCurrentOptimum.rst
142 .. include:: snippets/CostFunctionJo.rst
144 .. include:: snippets/CostFunctionJoAtCurrentOptimum.rst
146 .. include:: snippets/CurrentIterationNumber.rst
148 .. include:: snippets/CurrentOptimum.rst
150 .. include:: snippets/CurrentState.rst
152 .. include:: snippets/IndexOfOptimum.rst
154 .. ------------------------------------ ..
155 .. include:: snippets/Header2Algo06.rst
157 - :ref:`section_ref_algorithm_3DVAR`
158 - :ref:`section_ref_algorithm_KalmanFilter`
159 - :ref:`section_ref_algorithm_ExtendedKalmanFilter`
160 - :ref:`section_ref_algorithm_EnsembleKalmanFilter`
162 .. ------------------------------------ ..
163 .. include:: snippets/Header2Algo07.rst