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: LinearLeastSquares
25 .. _section_ref_algorithm_LinearLeastSquares:
27 Calculation algorithm "*LinearLeastSquares*"
28 --------------------------------------------
33 This algorithm realizes a "Least Squares" linear type estimation of the state of
34 a system. It is similar to the :ref:`section_ref_algorithm_Blue`, without its
37 This algorithm is always the fastest of all the optimization algorithms of ADAO.
38 It is theoretically reserved for observation operator cases which are linear,
39 even if it sometimes works in "slightly" non-linear cases. One can verify the
40 linearity of the observation operator with the help of the
41 :ref:`section_ref_algorithm_LinearityTest`.
43 In all cases, it is recommanded to prefer at least the
44 :ref:`section_ref_algorithm_Blue`, or the
45 :ref:`section_ref_algorithm_ExtendedBlue` or the
46 :ref:`section_ref_algorithm_3DVAR`.
48 Optional and required commands
49 ++++++++++++++++++++++++++++++
51 The general required commands, available in the editing user interface, are the
54 .. include:: snippets/Observation.rst
56 .. include:: snippets/ObservationError.rst
58 .. include:: snippets/ObservationOperator.rst
60 The general optional commands, available in the editing user interface, are
61 indicated in :ref:`section_ref_assimilation_keywords`. Moreover, the parameters
62 of the command "*AlgorithmParameters*" allows to choose the specific options,
63 described hereafter, of the algorithm. See
64 :ref:`section_ref_options_Algorithm_Parameters` for the good use of this
67 The options of the algorithm are the following:
69 StoreSupplementaryCalculations
70 .. index:: single: StoreSupplementaryCalculations
72 This list indicates the names of the supplementary variables that can be
73 available at the end of the algorithm. It involves potentially costly
74 calculations or memory consumptions. The default is a void list, none of
75 these variables being calculated and stored by default. The possible names
76 are in the following list: ["OMA", "CurrentState", "CostFunctionJ",
77 "CostFunctionJb", "CostFunctionJo", "SimulatedObservationAtCurrentState",
78 "SimulatedObservationAtOptimum"].
81 ``{"StoreSupplementaryCalculations":["OMA", "CurrentState"]}``
83 *Tips for this algorithm:*
85 As the *"Background"* and *"BackgroundError"* commands are required for ALL
86 the calculation algorithms in the interface, you have to provide a value,
87 even if these commands are not required for this algorithm, and will not be
88 used. The simplest way is to give "1" as a STRING for both.
90 Information and variables available at the end of the algorithm
91 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
93 At the output, after executing the algorithm, there are variables and
94 information originating from the calculation. The description of
95 :ref:`section_ref_output_variables` show the way to obtain them by the method
96 named ``get`` of the variable "*ADD*" of the post-processing. The input
97 variables, available to the user at the output in order to facilitate the
98 writing of post-processing procedures, are described in the
99 :ref:`subsection_r_o_v_Inventaire`.
101 The unconditional outputs of the algorithm are the following:
103 .. include:: snippets/Analysis.rst
105 .. include:: snippets/CostFunctionJ.rst
107 .. include:: snippets/CostFunctionJb.rst
109 .. include:: snippets/CostFunctionJo.rst
111 The conditional outputs of the algorithm are the following:
113 .. include:: snippets/OMA.rst
115 .. include:: snippets/SimulatedObservationAtOptimum.rst
121 References to other sections:
122 - :ref:`section_ref_algorithm_Blue`
123 - :ref:`section_ref_algorithm_ExtendedBlue`
124 - :ref:`section_ref_algorithm_3DVAR`
125 - :ref:`section_ref_algorithm_LinearityTest`