2 Copyright (C) 2008-2014 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: SamplingTest
25 .. _section_ref_algorithm_SamplingTest:
27 Checking algorithm "*SamplingTest*"
28 -----------------------------------
33 This algorithm allows to calculate the values, linked to a :math:`\mathbf{x}`
34 state, of a general error function :math:`J` of type :math:`L^1`, :math:`L^2` or
35 :math:`L^{\infty}`, with or without weights, and of the observation operator,
36 for an priori given states sample. The default error function is the augmented
37 weighted least squares function, classicaly used in data assimilation.
39 It is useful to test the sensitivity, of the error function :math:`J`, in
40 particular, to the state :math:`\mathbf{x}` variations. When a state is not
41 observable, a *"NaN"* value is returned.
43 The sampling of the states :math:`\mathbf{x}` can be given explicitly or under
44 the form of hyper-cubes, explicit or sampled. Be careful to the size of the
45 hyper-cube (and then to the number of calculations) that can be reached, it can
48 Optional and required commands
49 ++++++++++++++++++++++++++++++
51 .. index:: single: CheckingPoint
52 .. index:: single: BackgroundError
53 .. index:: single: Observation
54 .. index:: single: ObservationError
55 .. index:: single: ObservationOperator
56 .. index:: single: SampleAsnUplet
57 .. index:: single: SampleAsExplicitHyperCube
58 .. index:: single: SampleAsMinMaxStepHyperCube
59 .. index:: single: SampleAsIndependantRandomVariables
60 .. index:: single: QualityCriterion
61 .. index:: single: SetDebug
62 .. index:: single: SetSeed
63 .. index:: single: StoreSupplementaryCalculations
65 The general required commands, available in the editing user interface, are the
69 *Required command*. This indicates the vector used as the state around which
70 to perform the required check, noted :math:`\mathbf{x}` and similar to the
71 background :math:`\mathbf{x}^b`. It is defined as a "*Vector*" type object.
74 *Required command*. This indicates the background error covariance matrix,
75 previously noted as :math:`\mathbf{B}`. Its value is defined as a "*Matrix*"
76 type object, a "*ScalarSparseMatrix*" type object, or a
77 "*DiagonalSparseMatrix*" type object.
80 *Required command*. This indicates the observation vector used for data
81 assimilation or optimization, previously noted as :math:`\mathbf{y}^o`. It
82 is defined as a "*Vector*" or a *VectorSerie* type object.
85 *Required command*. This indicates the observation error covariance matrix,
86 previously noted as :math:`\mathbf{R}`. It is defined as a "*Matrix*" type
87 object, a "*ScalarSparseMatrix*" type object, or a "*DiagonalSparseMatrix*"
91 *Required command*. This indicates the observation operator, previously
92 noted :math:`H`, which transforms the input parameters :math:`\mathbf{x}` to
93 results :math:`\mathbf{y}` to be compared to observations
94 :math:`\mathbf{y}^o`. Its value is defined as a "*Function*" type object or
95 a "*Matrix*" type one. In the case of "*Function*" type, different
96 functional forms can be used, as described in the section
97 :ref:`section_ref_operator_requirements`. If there is some control :math:`U`
98 included in the observation, the operator has to be applied to a pair
101 The general optional commands, available in the editing user interface, are
102 indicated in :ref:`section_ref_assimilation_keywords`. In particular, the
103 optional command "*AlgorithmParameters*" allows to choose the specific options,
104 described hereafter, of the algorithm. See
105 :ref:`section_ref_options_AlgorithmParameters` for the good use of this command.
107 The options of the algorithm are the following:
110 This key describes the calculations points as a list of n-uplets, each
111 n-uplet being a state.
113 Example : ``{"SampleAsnUplet":[[0,1,2,3],[4,3,2,1],[-2,3,-4,5]]}`` for 3 points in a state space of dimension 4
115 SampleAsExplicitHyperCube
116 This key describes the calculations points as an hyper-cube, from a given
117 list of explicit sampling of each variable as a list. That is then a list of
118 lists, each of them being potentially of different size.
120 Example : ``{"SampleAsExplicitHyperCube":[[0.,0.25,0.5,0.75,1.],[-2,2,1]]}`` for a state space of dimension 2
122 SampleAsMinMaxStepHyperCube
123 This key describes the calculations points as an hyper-cube, from a given
124 list of implicit sampling of each variable by a triplet *[min,max,step]*.
125 That is then a list of the same size than the one of the state. The bounds
128 Example : ``{"SampleAsMinMaxStepHyperCube":[[0.,1.,0.25],[-1,3,1]]}`` for a state space of dimension 2
130 SampleAsIndependantRandomVariables
131 This key describes the calculations points as an hyper-cube, for which the
132 points on each axis come from a independant random sampling of the axis
133 variable, under the specification of the distribution, its parameters and
134 the number of points in the sample, as a list ``['distribution',
135 [parametres], nombre]`` for each axis. The possible distributions are
136 'normal' of parameters (mean,std), 'lognormal' of parameters (mean,sigma),
137 'uniform' of parameters (low,high), or 'weibull' of parameter (shape). That
138 is then a list of the same size than the one of the state.
140 Example : ``{"SampleAsIndependantRandomVariables":[['normal',[0.,1.],3],['uniform',[-2,2],4]]`` for a state space of dimension 2
143 This key indicates the quality criterion, used to find the state estimate.
144 The default is the usual data assimilation criterion named "DA", the
145 augmented weighted least squares. The possible criteria has to be in the
146 following list, where the equivalent names are indicated by the sign "=":
147 ["AugmentedWeightedLeastSquares"="AWLS"="DA", "WeightedLeastSquares"="WLS",
148 "LeastSquares"="LS"="L2", "AbsoluteValue"="L1", "MaximumError"="ME"].
150 Example : ``{"QualityCriterion":"DA"}``
153 This key requires the activation, or not, of the debug mode during the
154 function evaluation. The default is "True", the choices are "True" or
157 Example : ``{"SetDebug":False}``
160 This key allow to give an integer in order to fix the seed of the random
161 generator used to generate the ensemble. A convenient value is for example
162 1000. By default, the seed is left uninitialized, and so use the default
163 initialization from the computer.
165 Example : ``{"SetSeed":1000}``
167 StoreSupplementaryCalculations
168 This list indicates the names of the supplementary variables that can be
169 available at the end of the algorithm. It involves potentially costly
170 calculations or memory consumptions. The default is a void list, none of
171 these variables being calculated and stored by default. The possible names
172 are in the following list: ["CostFunctionJ", "CurrentState", "Innovation",
175 Example : ``{"StoreSupplementaryCalculations":["CostFunctionJ", "ObservedState"]}``
180 References to other sections:
181 - :ref:`section_ref_algorithm_FunctionTest`