2 Copyright (C) 2008-2015 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: ParticleSwarmOptimization
25 .. _section_ref_algorithm_ParticleSwarmOptimization:
27 Calculation algorithm "*ParticleSwarmOptimization*"
28 ---------------------------------------------------
33 This algorithm realizes an estimation of the state of a dynamic system by a
36 This is an optimization method allowing for global minimum search of a general
37 error function :math:`J` of type :math:`L^1`, :math:`L^2` or :math:`L^{\infty}`,
38 with or without weights. The default error function is the augmented weighted
39 least squares function, classicaly used in data assimilation.
41 Optional and required commands
42 ++++++++++++++++++++++++++++++
44 .. index:: single: Background
45 .. index:: single: BackgroundError
46 .. index:: single: Observation
47 .. index:: single: ObservationError
48 .. index:: single: ObservationOperator
49 .. index:: single: MaximumNumberOfSteps
50 .. index:: single: NumberOfInsects
51 .. index:: single: SwarmVelocity
52 .. index:: single: GroupRecallRate
53 .. index:: single: QualityCriterion
54 .. index:: single: BoxBounds
55 .. index:: single: SetSeed
56 .. index:: single: StoreSupplementaryCalculations
58 The general required commands, available in the editing user interface, are the
62 *Required command*. This indicates the background or initial vector used,
63 previously noted as :math:`\mathbf{x}^b`. Its value is defined as a
64 "*Vector*" or a *VectorSerie*" type object.
67 *Required command*. This indicates the background error covariance matrix,
68 previously noted as :math:`\mathbf{B}`. Its value is defined as a "*Matrix*"
69 type object, a "*ScalarSparseMatrix*" type object, or a
70 "*DiagonalSparseMatrix*" type object.
73 *Required command*. This indicates the observation vector used for data
74 assimilation or optimization, previously noted as :math:`\mathbf{y}^o`. It
75 is defined as a "*Vector*" or a *VectorSerie* type object.
78 *Required command*. This indicates the observation error covariance matrix,
79 previously noted as :math:`\mathbf{R}`. It is defined as a "*Matrix*" type
80 object, a "*ScalarSparseMatrix*" type object, or a "*DiagonalSparseMatrix*"
84 *Required command*. This indicates the observation operator, previously
85 noted :math:`H`, which transforms the input parameters :math:`\mathbf{x}` to
86 results :math:`\mathbf{y}` to be compared to observations
87 :math:`\mathbf{y}^o`. Its value is defined as a "*Function*" type object or
88 a "*Matrix*" type one. In the case of "*Function*" type, different
89 functional forms can be used, as described in the section
90 :ref:`section_ref_operator_requirements`. If there is some control :math:`U`
91 included in the observation, the operator has to be applied to a pair
94 The general optional commands, available in the editing user interface, are
95 indicated in :ref:`section_ref_assimilation_keywords`. In particular, the
96 optional command "*AlgorithmParameters*" allows to choose the specific options,
97 described hereafter, of the algorithm. See
98 :ref:`section_ref_options_AlgorithmParameters` for the good use of this command.
100 The options of the algorithm are the following:
103 This key indicates the maximum number of iterations allowed for iterative
104 optimization. The default is 50, which is an arbitrary limit. It is then
105 recommended to adapt this parameter to the needs on real problems.
107 Example : ``{"MaximumNumberOfSteps":100}``
110 This key indicates the number of insects or particles in the swarm. The
111 default is 100, which is a usual default for this algorithm.
113 Example : ``{"NumberOfInsects":100}``
116 This key indicates the part of the insect velocity which is imposed by the
117 swarm. It is a positive floating point value. The default value is 1.
119 Example : ``{"SwarmVelocity":1.}``
122 This key indicates the recall rate at the best swarm insect. It is a
123 floating point value between 0 and 1. The default value is 0.5.
125 Example : ``{"GroupRecallRate":0.5}``
128 This key indicates the quality criterion, minimized to find the optimal
129 state estimate. The default is the usual data assimilation criterion named
130 "DA", the augmented weighted least squares. The possible criteria has to be
131 in the following list, where the equivalent names are indicated by the sign
132 "=": ["AugmentedWeightedLeastSquares"="AWLS"="DA",
133 "WeightedLeastSquares"="WLS", "LeastSquares"="LS"="L2",
134 "AbsoluteValue"="L1", "MaximumError"="ME"].
136 Example : ``{"QualityCriterion":"DA"}``
139 This key allows to define upper and lower bounds for *increments* on every
140 state variable being optimized (and not on state variables themselves).
141 Bounds have to be given by a list of list of pairs of lower/upper bounds for
142 each increment on variable, with extreme values every time there is no bound
143 (``None`` is not allowed when there is no bound). This key is required and
144 there is no default values.
146 Example : ``{"BoxBounds":[[-0.5,0.5],[0.01,2.],[0.,1.e99],[-1.e99,1.e99]]}``
149 This key allow to give an integer in order to fix the seed of the random
150 generator used to generate the ensemble. A convenient value is for example
151 1000. By default, the seed is left uninitialized, and so use the default
152 initialization from the computer.
154 Example : ``{"SetSeed":1000}``
156 StoreSupplementaryCalculations
157 This list indicates the names of the supplementary variables that can be
158 available at the end of the algorithm. It involves potentially costly
159 calculations or memory consumptions. The default is a void list, none of
160 these variables being calculated and stored by default. The possible names
161 are in the following list: ["BMA", "CostFunctionJ", "CurrentState", "OMA",
162 "OMB", "Innovation", "SimulatedObservationAtBackground",
163 "SimulatedObservationAtCurrentState", "SimulatedObservationAtOptimum"].
165 Example : ``{"StoreSupplementaryCalculations":["BMA","Innovation"]}``
167 Information and variables available at the end of the algorithm
168 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
170 At the output, after executing the algorithm, there are variables and
171 information originating from the calculation. The description of
172 :ref:`section_ref_output_variables` show the way to obtain them by the method
173 named ``get`` of the variable "*ADD*" of the post-processing. The input
174 variables, available to the user at the output in order to facilitate the
175 writing of post-processing procedures, are described in the
176 :ref:`subsection_r_o_v_Inventaire`.
178 The unconditional outputs of the algorithm are the following:
181 *List of vectors*. Each element is an optimal state :math:`\mathbf{x}*` in
182 optimization or an analysis :math:`\mathbf{x}^a` in data assimilation.
184 Example : ``Xa = ADD.get("Analysis")[-1]``
187 *List of values*. Each element is a value of the error function :math:`J`.
189 Example : ``J = ADD.get("CostFunctionJ")[:]``
192 *List of values*. Each element is a value of the error function :math:`J^b`,
193 that is of the background difference part.
195 Example : ``Jb = ADD.get("CostFunctionJb")[:]``
198 *List of values*. Each element is a value of the error function :math:`J^o`,
199 that is of the observation difference part.
201 Example : ``Jo = ADD.get("CostFunctionJo")[:]``
203 The conditional outputs of the algorithm are the following:
206 *List of vectors*. Each element is a vector of difference between the
207 background and the optimal state.
209 Example : ``bma = ADD.get("BMA")[-1]``
212 *List of vectors*. Each element is a usual state vector used during the
213 optimization algorithm procedure.
215 Example : ``Xs = ADD.get("CurrentState")[:]``
218 *List of vectors*. Each element is an innovation vector, which is in static
219 the difference between the optimal and the background, and in dynamic the
222 Example : ``d = ADD.get("Innovation")[-1]``
225 *List of vectors*. Each element is a vector of difference between the
226 observation and the optimal state in the observation space.
228 Example : ``oma = ADD.get("OMA")[-1]``
231 *List of vectors*. Each element is a vector of difference between the
232 observation and the background state in the observation space.
234 Example : ``omb = ADD.get("OMB")[-1]``
236 SimulatedObservationAtBackground
237 *List of vectors*. Each element is a vector of observation simulated from
238 the background :math:`\mathbf{x}^b`.
240 Example : ``hxb = ADD.get("SimulatedObservationAtBackground")[-1]``
242 SimulatedObservationAtCurrentState
243 *List of vectors*. Each element is an observed vector at the current state,
244 that is, in the observation space.
246 Example : ``Ys = ADD.get("SimulatedObservationAtCurrentState")[-1]``
248 SimulatedObservationAtOptimum
249 *List of vectors*. Each element is a vector of observation simulated from
250 the analysis or optimal state :math:`\mathbf{x}^a`.
252 Example : ``hxa = ADD.get("SimulatedObservationAtOptimum")[-1]``
257 References to other sections: