├── .gitignore
├── Make
    ├── files
    └── options
├── .vscode
    ├── settings.json
    ├── tasks.json
    └── c_cpp_properties.json
├── .gitlab-ci.yml
├── README.md
├── convergenceDetectionDict
├── convergenceDetection.H
├── convergenceDetection.C
└── LICENSE


/.gitignore:
--------------------------------------------------------------------------------
1 | InInclde*
2 | Make/linux64GccDPInt32Opt/*
3 | 


--------------------------------------------------------------------------------
/Make/files:
--------------------------------------------------------------------------------
1 | convergenceDetection.C
2 | 
3 | LIB = $(FOAM_USER_LIBBIN)/libconvergenceDetection
4 | 


--------------------------------------------------------------------------------
/.vscode/settings.json:
--------------------------------------------------------------------------------
 1 | {
 2 |   "files.associations": {
 3 |     "*Dict": "OpenFOAM",
 4 |     "*Properties": "OpenFOAM",
 5 |     "fvSchemes": "OpenFOAM",
 6 |     "fvSolution": "OpenFOAM",
 7 |     "**/constant/g": "OpenFOAM",
 8 |     "**/0/*": "OpenFOAM",
 9 |     "averaging": "OpenFOAM",
10 |     "convergenceDetection.C": "cpp",
11 |     "convergenceDetection.H": "cpp"
12 |   }
13 | }


--------------------------------------------------------------------------------
/.vscode/tasks.json:
--------------------------------------------------------------------------------
 1 | {
 2 |     "version": "2.0.0",
 3 |     "tasks": [
 4 |         {
 5 |             "type": "shell",
 6 |             "label": "wmake-build",
 7 |             "command": "wmake -j",
 8 |             "problemMatcher": [
 9 |                 "$gcc"
10 |             ],
11 |             "group": {
12 |                 "kind": "build",
13 |                 "isDefault": true
14 |             }
15 |         }
16 |     ]
17 | }


--------------------------------------------------------------------------------
/Make/options:
--------------------------------------------------------------------------------
 1 | EXE_INC = \
 2 |     -I$(LIB_SRC)/finiteVolume/lnInclude \
 3 |     -I$(LIB_SRC)/meshTools/lnInclude \
 4 |     -I$(LIB_SRC)/functionObjects/forces/lnInclude \
 5 |     -I$(LIB_SRC)/functionObjects/field/lnInclude \
 6 |     -I$(LIB_SRC)/surfMesh/lnInclude \
 7 |     -I$(LIB_SRC)/sampling/lnInclude
 8 | 
 9 | LIB_LIBS = \
10 |     -lfiniteVolume \
11 |     -lmeshTools \
12 |     -lforces \
13 |     -lfieldFunctionObjects \
14 |     -lsurfMesh \
15 |     -lsampling
16 | 


--------------------------------------------------------------------------------
/.vscode/c_cpp_properties.json:
--------------------------------------------------------------------------------
 1 | {
 2 |     "configurations": [
 3 |         {
 4 |             "name": "Linux",
 5 |             "includePath": [
 6 |                 "${workspaceFolder}/**",
 7 |                 "/usr/lib/openfoam/openfoam2206/src/**"
 8 |             ],
 9 |             "defines": [],
10 |             "compilerPath": "/usr/bin/gcc",
11 |             "cStandard": "gnu11",
12 |             "cppStandard": "gnu++14",
13 |             "intelliSenseMode": "gcc-x86"
14 |         }
15 |     ],
16 |     "version": 4
17 | }


--------------------------------------------------------------------------------
/.gitlab-ci.yml:
--------------------------------------------------------------------------------
 1 | image: "google/cloud-sdk:alpine"
 2 | 
 3 | stages:
 4 |   - upload
 5 | 
 6 | before_script:
 7 |   - echo "$GOOGLE_SERVICE_ACCOUNT" >> "/root/google.json"
 8 | 
 9 | upload_zip:
10 |   stage: upload
11 |   script:
12 |     - git archive -o ${CI_PROJECT_NAME}-${CI_COMMIT_REF_NAME}.zip -9 HEAD
13 |     - gcloud auth activate-service-account --project=halogen-chemist-162620 --key-file=/root/google.json
14 |     - gsutil -h Cache-Control:private cp ./${CI_PROJECT_NAME}-${CI_COMMIT_REF_NAME}.zip gs://airshaper-releases
15 |   except:
16 |     - /^feature\/.*$/
17 |   tags:
18 |     - feature
19 | 


--------------------------------------------------------------------------------
/README.md:
--------------------------------------------------------------------------------
 1 | # Openfoam.com convergence detection
 2 | 
 3 | ## Motivation
 4 | 
 5 | Why we think this is better when runTimeControl in openfoam and residuals
 6 | 
 7 | ## How it works
 8 | 
 9 | This functionObject runs every iteration, it pulls force data and it stores the total force which is later used for the gradient calculation.
10 | 
11 | ## Parameters explanation
12 | 
13 | ### windowNormalization 0.5;
14 | 
15 | ### windowGradient 0.5;
16 | 
17 | ### windowGradientAveraging 0.99;
18 | 
19 | ### windowEvaluation 0.333;
20 | 
21 | ### windowEvaluationAveraging 0.333;
22 | 
23 | ### thresholdConvergence 0.075;
24 | 
25 | ### thresholdAveraging 0.025;
26 | 
27 | ### iterationMaxConvergence 4000;
28 | 
29 | If simulation does not converge start forced averging at 4000 iterations
30 | 
31 | ### iterationMaxAveraging 2000;
32 | 
33 | If simulation does not converge within 4000 iterations run 2000 averaging iterations so in total simulation will have 6000 iterations
34 | 
35 | ### iterationMinConvergence 200;
36 | 
37 | Minimum number of iterations in case simulation converges before 200 iterations
38 | 
39 | ### iterationMinAveraging 200;
40 | 
41 | Minimum number of averaging iterations in case simulation converges at iterationMinConvergence
42 | 
43 | ### forceStabilityFactor 2;
44 | 
45 | In case forces explode this factor is used to check if forces are 2 times higher or lower when the converged value and in case of that it stops the simulation. If this happens it means your mesh is not good enough.
46 | 
47 | ## Credits
48 | 
49 | Original Python implementation by João Miranda
50 | 
51 | OpenFoam C++ Implementation by Nikola Majksner
52 | 


--------------------------------------------------------------------------------
/convergenceDetectionDict:
--------------------------------------------------------------------------------
 1 | convergenceDetection1
 2 | {
 3 |     libs (libconvergenceDetection);
 4 |     type convergenceDetection;
 5 | 
 6 |     // default settings
 7 |     // windowNormalization 0.5;
 8 |     // windowGradient 0.5;
 9 |     // windowGradientAveraging 0.99;
10 |     // windowEvaluation 0.333;
11 |     // windowEvaluationAveraging 0.333;
12 |     // thresholdConvergence 0.075;
13 |     // thresholdAveraging 0.025;
14 |     // iterationMaxConvergence 4000;
15 |     // iterationMaxAveraging 2000;
16 |     // iterationMinConvergence 200;
17 |     // iterationMinAveraging 200;
18 |     // convergenceStabilityFactor 2;
19 | 
20 |     rotation_forces {
21 |         forces_rotation_local_CS_o-1_m-1
22 |         {
23 | 
24 |             type forces;
25 |             libs ("libforces.so"); //Lib to load
26 |             patches (rotating_o-1_m-1); // change to your patch name
27 |             writeControl    outputTime;
28 |             writeToFile     false;
29 |             pName       p;
30 |             UName       U;
31 |             rho     rhoInf;     // Indicates incompressible
32 |             log         yes;
33 |             rhoInf 1.225; //Reference density for fluid
34 |             origin (5.7195773108383204e-05 0.00048790520819794116 -7.06637150485188e-09);
35 |             rotation
36 |             {
37 |                 type axes;
38 |                 e1 (0.018186134589979835 0.0012717031291784764 -1.3326080284815782e-09);
39 |                 e2 (1.2717044617865047e-13 -1.334426641940576e-09 -0.001271703127359863);
40 |                 e3 (-1.6172288464513707e-06 2.3127364232664738e-05 -2.4268224233840492e-11);
41 |             }
42 |         }
43 |     }
44 |     
45 |     // forces - required
46 |     // modify according to your case
47 |     patches         ( #CHANGEME# ); 
48 |     rho             rhoInf;
49 |     log             false;
50 |     rhoInf          1.225; // for water 1000
51 |     CofR            ( 0 0 0 );
52 |     // end of forces  - required
53 | 
54 |     writeControl    timeStep;
55 |     timeInterval    1;
56 |     log             true;
57 | }


--------------------------------------------------------------------------------
/convergenceDetection.H:
--------------------------------------------------------------------------------
  1 | /*---------------------------------------------------------------------------*\
  2 |   =========                 |
  3 |   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
  4 |    \\    /   O peration     |
  5 |     \\  /    A nd           | www.openfoam.com
  6 |      \\/     M anipulation  |
  7 | -------------------------------------------------------------------------------
  8 |     Copyright (C) 2022 Nikola Majksner, Wouter Remmerie, AirShaper
  9 | -------------------------------------------------------------------------------
 10 | License
 11 |     This file is part of OpenFOAM.
 12 | 
 13 |     OpenFOAM is free software: you can redistribute it and/or modify it
 14 |     under the terms of the GNU General Public License as published by
 15 |     the Free Software Foundation, either version 3 of the License, or
 16 |     (at your option) any later version.
 17 | 
 18 |     OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
 19 |     ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 20 |     FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 21 |     for more details.
 22 | 
 23 |     You should have received a copy of the GNU General Public License
 24 |     along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
 25 | 
 26 | Class
 27 |     Foam::functionObjects::convergenceDetection
 28 | 
 29 | Group
 30 |     grpFieldFunctionObjects
 31 | 
 32 | Description
 33 |     <minimal description of the function object>
 34 | 
 35 |     <equation>
 36 |     \f[
 37 |         x = x_{ref}^x + \rho \omega
 38 |     \f]
 39 | 
 40 |     <variable-explanation table>
 41 |     where
 42 |     \vartable
 43 |       \rho        | <explanation> [units, e.g. kg/m3]
 44 |       \omega      | \f$ \nabla \cdot \vec U \f$
 45 |       ...         | ...
 46 |     \endvartable
 47 | 
 48 |     <inline equation>
 49 |     where \f$ x_k \f$ is ...
 50 | 
 51 |     <input-output table>
 52 |     \table
 53 |       Operand      | Type                 | Location
 54 |       input        | {vol,surface}\<Type\>Field(s) <!--
 55 |                --> |$FOAM_CASE/\<time\>/\<inpField\>s
 56 |       output file  | dat                  <!--
 57 |               -->  | $FOAM_CASE/postProcessing/\<FO\>/\<time\>/\<file\>
 58 |       output field | volScalarField       | $FOAM_CASE/\<time\>/\<outField\>
 59 |     \endtable
 60 | 
 61 | Usage
 62 |     Minimal example by using \c system/controlDict.functions:
 63 |     \verbatim
 64 |     convergenceDetection1
 65 |     {
 66 |         // Mandatory entries (unmodifiable)
 67 |         type           convergenceDetection;
 68 |         libs           (convergenceDetectionFunctionObject);
 69 | 
 70 |         // Mandatory entries (runtime modifiable)
 71 |         ...
 72 | 
 73 |         // Mandatory (inherited) entries (unmodifiable)
 74 |         ...
 75 | 
 76 |         // Mandatory (inherited) entries (runtime unmodifiable)
 77 |         ...
 78 | 
 79 |         // Optional entries (unmodifiable)
 80 |         ...
 81 | 
 82 |         // Optional entries (runtime modifiable)
 83 |         boolData       <bool>;
 84 |         labelData      <label>;
 85 |         wordData       <word>;
 86 |         scalarData     <scalar>;
 87 | 
 88 |         // Optional (inherited) entries
 89 |         ...
 90 |     }
 91 |     \endverbatim
 92 | 
 93 |     where the entries mean:
 94 |     \table
 95 |       Property   | Description                      | Type | Req'd | Dflt
 96 |       type       | Type name: convergenceDetection        | word |  yes  | -
 97 |       libs       | Library name: convergenceDetectionFunctionObject  <!--
 98 |              --> | word  | yes | -
 99 |       boolData   | <explanation>                    | bool |  yes  | -
100 |       labelData  | <explanation>                    | label |  yes | -
101 |       wordData   | <explanation>                    | word |  yes  | -
102 |       scalarData | <explanation>                    | scalar |  no | 1.0
103 |       wordListData  | <explanation>                 | wordList | yes | -
104 |     \endtable
105 | 
106 |     Options for the \c ENTRY entry:
107 |     \verbatim
108 |         <option1>
109 |         <option2> | <explanation>
110 |       ...
111 |     \endverbatim
112 | 
113 |     The inherited entries are elaborated in:
114 |      - \link functionObject.H \endlink
115 |      - \link fieldExpression.H \endlink
116 |      - \link fieldsExpression.H \endlink
117 |      - \link writeFile.H \endlink
118 |      ...
119 | 
120 |     <if \c postProcess is applicable>
121 |     Minimal example by using the \c postProcess utility:
122 |     \verbatim
123 |         postProcess -func convergenceDetection
124 |     \endverbatim
125 | 
126 |     <if \c postProcess is not applicable>
127 |     Usage by the \c postProcess utility is not available.
128 | 
129 | Note
130 |     - <note1>
131 |     - <note2>
132 |     ...
133 | 
134 | See also
135 |     - Foam::functionObject
136 |     - Foam::functionObjects::fvMeshFunctionObject
137 |     - ExtendedCodeGuide::functionObjects::field::convergenceDetection
138 |     ...
139 | 
140 | SourceFiles
141 |     convergenceDetection.C
142 |     convergenceDetectionTEMPLATES.C
143 |     ...
144 | 
145 | \*---------------------------------------------------------------------------*/
146 | 
147 | #ifndef convergenceDetection_H
148 | #define convergenceDetection_H
149 | 
150 | #include "forces.H"
151 | #include "surfaceFieldValue.H"
152 | #include "coordinateSystem.H"
153 | 
154 | using namespace Foam::functionObjects::fieldValues;
155 | using namespace Foam::functionObjects;
156 | 
157 | // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
158 | 
159 | namespace Foam
160 | {
161 |     namespace functionObjects
162 |     {
163 | 
164 |         /*---------------------------------------------------------------------------*\
165 |                            Class convergenceDetection Declaration
166 |         \*---------------------------------------------------------------------------*/
167 | 
168 |         class convergenceDetection
169 |             : public forces
170 |         {
171 | 
172 |         protected:
173 |             // virtual double meanValue(std::vector<double>& forces_);
174 |             // virtual double calculate_Gradient_grad(std::vector<double> forces_);
175 | 
176 |             scalar windowNormalization_;
177 |             scalar windowGradient_;
178 |             scalar windowGradientAveraging_;
179 | 
180 |             scalar windowEvaluation_;
181 |             scalar windowEvaluationAveraging_;
182 |             scalar thresholdConvergence_;
183 |             scalar thresholdAveraging_;
184 |             scalar iterationMaxConvergence_;
185 |             scalar iterationMaxAveraging_;
186 |             scalar convergenceStabilityFactor_;
187 |             scalar iterationMinConvergence_;
188 |             scalar iterationMinAveraging_;
189 |             bool convergenceFound_;
190 |             bool simulationFinished_;
191 |             bool forcedConvergence_;
192 |             int currentIteration_;
193 |             int averagingStartedAt_;
194 |             wordRes patches_;
195 |             word rho_;
196 |             scalar rhoInf_;
197 |             vector CofR_;
198 |             std::map<std::string, double> normalizedDataMeanConverged_;
199 |             wordList porousObjectsNames_;
200 |             wordList rotatingObjectsNames_;
201 |             std::vector<word> porousNames_;
202 |             std::vector<word> rotatingNames_;
203 |             std::vector<surfaceFieldValue *> porousObjects_;
204 |             std::vector<functionObjects::forces *> rotatingObjects_;
205 |             autoPtr<coordinateSystem> coordSysPtrC_;
206 |             std::map<std::string, std::vector<double>>
207 |                 convergenceData_;
208 |             std::map<std::string, std::vector<double>> gradData_;
209 |             std::map<std::string, std::vector<double>> gradDataAveraging_;
210 |             std::map<std::string, std::vector<double>> convergenceNormalized_;
211 |             std::map<std::string, std::vector<double>> dataNormalized_;
212 |             std::map<std::string, std::vector<double>> convergenceNormalizedAveraging_;
213 |             autoPtr<OFstream> totalForceFilePtr_;
214 |             autoPtr<OFstream> gradientFilePtr_;
215 |             autoPtr<OFstream> gradientAveragedFilePtr_;
216 | 
217 |             virtual std::map<std::string, std::vector<double>> divideData(std::map<std::string, double> dataMean);
218 |             virtual std::map<std::string, double> meanValue(std::map<std::string, std::vector<double>> normalizedData);
219 |             virtual std::map<std::string, double> calculateGradient();
220 |             virtual std::map<std::string, double> calculateGradientAveraging();
221 |             virtual std::map<std::string, double> convergenceMaxGradient();
222 |             virtual std::map<std::string, double> averagingMaxGradient();
223 |             virtual void stopAveraging();
224 |             virtual void isFinished();
225 |             virtual void convergenceEvaluation();
226 |             virtual void isExploded();
227 |             virtual void createDataFile();
228 |             virtual bool reachedMaxIterations();
229 |             virtual bool minIterationsForAveraging();
230 |             virtual bool isAveraged();
231 |             virtual void writeDataFileHeader(const word &header, const word &tabbedName, OFstream &os) const;
232 |             virtual void writeDataFile(OFstream &os, double &value) const;
233 |             virtual double polyfit(const std::vector<double> x,
234 |                                    const std::vector<double> y,
235 |                                    const int order,
236 |                                    std::vector<double> coeffs);
237 |             virtual std::vector<double> arange(double start, double stop, double step);
238 | 
239 |             virtual void toggleAveraging(bool toggle);
240 | 
241 |         public:
242 |             //- Runtime type information
243 |             TypeName("convergenceDetection");
244 | 
245 |             // Constructors
246 | 
247 |             //- Construct from Time and dictionary
248 |             convergenceDetection(
249 |                 const word &name,
250 |                 const Time &runTime,
251 |                 const dictionary &dict);
252 | 
253 |             //- No copy construct
254 |             convergenceDetection(const convergenceDetection &) = delete;
255 | 
256 |             //- No copy assignment
257 |             void operator=(const convergenceDetection &) = delete;
258 | 
259 |             //- Destructor
260 |             virtual ~convergenceDetection() = default;
261 | 
262 |             // Member Functions
263 | 
264 |             //- Read the convergenceDetection data
265 |             virtual bool read(const dictionary &dict);
266 | 
267 |             //- Execute, currently does nothing
268 |             virtual bool execute();
269 | 
270 |             //- Execute at the final time-loop, currently does nothing
271 |             virtual bool end();
272 | 
273 |             //- Write the convergenceDetection
274 |             virtual bool write();
275 |         };
276 | 
277 |         // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
278 | 
279 |     } // End namespace functionObjects
280 | } // End namespace Foam
281 | 
282 | // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
283 | 
284 | // #ifdef NoRepository
285 | //     #include "convergenceDetectionTemplates.C"
286 | // #endif
287 | 
288 | #endif
289 | 
290 | // ************************************************************************* //


--------------------------------------------------------------------------------
/convergenceDetection.C:
--------------------------------------------------------------------------------
  1 | /*---------------------------------------------------------------------------*\
  2 |   =========                 |
  3 |   \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
  4 |    \\    /   O peration     |
  5 |     \\  /    A nd           | www.openfoam.com
  6 |      \\/     M anipulation  |
  7 | -------------------------------------------------------------------------------
  8 |     Copyright (C) 2022 Nikola Majksner, Wouter Remmerie, AirShaper
  9 | -------------------------------------------------------------------------------
 10 | License
 11 |     This file is part of OpenFOAM.
 12 | 
 13 |     OpenFOAM is free software: you can redistribute it and/or modify it
 14 |     under the terms of the GNU General Public License as published by
 15 |     the Free Software Foundation, either version 3 of the License, or
 16 |     (at your option) any later version.
 17 | 
 18 |     OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
 19 |     ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 20 |     FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 21 |     for more details.
 22 | 
 23 |     You should have received a copy of the GNU General Public License
 24 |     along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
 25 | 
 26 | \*---------------------------------------------------------------------------*/
 27 | 
 28 | #include "convergenceDetection.H"
 29 | #include "Time.H"
 30 | #include "addToRunTimeSelectionTable.H"
 31 | #include "cartesianCS.H"
 32 | #include <vector>
 33 | #include <algorithm>
 34 | #include <map>
 35 | 
 36 | using namespace Foam::functionObjects::fieldValues;
 37 | 
 38 | // * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //
 39 | 
 40 | namespace Foam
 41 | {
 42 |     namespace functionObjects
 43 |     {
 44 |         defineTypeNameAndDebug(convergenceDetection, 0);
 45 |         addToRunTimeSelectionTable(functionObject, convergenceDetection, dictionary);
 46 |     }
 47 | }
 48 | 
 49 | // * * * * * * * * * * * * * * * * Constructors  * * * * * * * * * * * * * * //
 50 | 
 51 | Foam::functionObjects::convergenceDetection::convergenceDetection(
 52 |     const word &name,
 53 |     const Time &runTime,
 54 |     const dictionary &dict)
 55 |     : forces(name, runTime, dict, false),
 56 |       windowNormalization_(0.5),
 57 |       windowGradient_(0.5),
 58 |       windowGradientAveraging_(0.99),
 59 |       windowEvaluation_(0.333),
 60 |       windowEvaluationAveraging_(0.333),
 61 |       thresholdConvergence_(0.075),
 62 |       thresholdAveraging_(0.025),
 63 |       iterationMaxConvergence_(4000),
 64 |       iterationMaxAveraging_(2000),
 65 |       convergenceStabilityFactor_(2),
 66 |       iterationMinConvergence_(200),
 67 |       iterationMinAveraging_(200),
 68 |       convergenceFound_(false),
 69 |       simulationFinished_(false),
 70 |       forcedConvergence_(false),
 71 |       currentIteration_(0),
 72 |       averagingStartedAt_(0),
 73 |       patches_(wordRes()),
 74 |       rho_("rhoInf"),
 75 |       rhoInf_(1.225),
 76 |       CofR_(Zero),
 77 |       normalizedDataMeanConverged_(),
 78 |       porousObjectsNames_(),
 79 |       rotatingObjectsNames_(),
 80 |       porousNames_(),
 81 |       rotatingNames_(),
 82 |       porousObjects_(),
 83 |       rotatingObjects_(),
 84 |       coordSysPtrC_(nullptr),
 85 |       convergenceData_(),
 86 |       gradData_(),
 87 |       gradDataAveraging_(),
 88 |       convergenceNormalized_(),
 89 |       dataNormalized_(),
 90 |       convergenceNormalizedAveraging_(),
 91 |       totalForceFilePtr_(nullptr),
 92 |       gradientFilePtr_(nullptr),
 93 |       gradientAveragedFilePtr_(nullptr)
 94 | 
 95 | {
 96 |     read(dict);
 97 | 
 98 |     setCoordinateSystem(dict);
 99 | 
100 |     if (dict.found("porous"))
101 |     {
102 |         porousObjectsNames_ = dict.subDict("porous").toc();
103 |         for (const word &name : porousObjectsNames_)
104 |         {
105 |             porousObjects_.push_back(new surfaceFieldValue(name, runTime, dict.subDict("porous").subDict(name)));
106 |             const dictionary &porousSubDict = dict.subDict("porous").subDict(name);
107 |             word porousName = porousSubDict.lookupOrDefault<word>("name", name);
108 |             porousNames_.push_back(porousName);
109 |         }
110 |     }
111 | 
112 |     if (dict.found("rotation_forces"))
113 |     {
114 |         rotatingObjectsNames_ = dict.subDict("rotation_forces").toc();
115 |         for (const word &name : rotatingObjectsNames_)
116 |         {
117 |             rotatingObjects_.push_back(new forces(name, runTime, dict.subDict("rotation_forces").subDict(name)));
118 |             coordSysPtrC_.clear();
119 |             coordSysPtrC_.reset(new coordSystem::cartesian(dict.subDict("rotation_forces").subDict(name)));
120 |             const dictionary &rotatingSubDict = dict.subDict("rotation_forces").subDict(name);
121 |             word rotatingName = rotatingSubDict.lookupOrDefault<word>("name", name);
122 |             rotatingNames_.push_back(rotatingName);
123 |         }
124 |     }
125 | }
126 | 
127 | // * * * * * * * * * * * * * * * Member Functions  * * * * * * * * * * * * * //
128 | 
129 | bool Foam::functionObjects::convergenceDetection::read(const dictionary &dict)
130 | {
131 |     forces::read(dict);
132 | 
133 |     dict.readIfPresent("windowNormalization", windowNormalization_);
134 |     dict.readIfPresent("windowGradient", windowGradient_);
135 |     dict.readIfPresent("windowGradientAveraging", windowGradientAveraging_);
136 |     dict.readIfPresent("windowEvaluation", windowEvaluation_);
137 |     dict.readIfPresent("windowEvaluationAveraging", windowEvaluationAveraging_);
138 |     dict.readIfPresent("thresholdConvergence", thresholdConvergence_);
139 |     dict.readIfPresent("thresholdAveraging", thresholdAveraging_);
140 |     dict.readIfPresent("iterationMaxConvergence", iterationMaxConvergence_);
141 |     dict.readIfPresent("iterationMaxAveraging", iterationMaxAveraging_);
142 |     dict.readIfPresent("convergenceStabilityFactor_", convergenceStabilityFactor_);
143 |     dict.readIfPresent("iterationMinConvergence", iterationMinConvergence_);
144 |     dict.readIfPresent("iterationMinAveraging", iterationMinAveraging_);
145 | 
146 |     if (!exists(time().globalPath() + "/system/averaging"))
147 |     {
148 |         FatalError
149 |             << "Averaging file does not exists, please create averaging file in system/averaging and include it in controlDict (#include \"averaging\")" << nl
150 |             << "https://www.openfoam.com/documentation/guides/latest/doc/guide-fos-field-fieldAverage.html" << nl
151 |             << abort(FatalError);
152 | 
153 |         return false;
154 |     }
155 | 
156 |     return true;
157 | }
158 | 
159 | bool Foam::functionObjects::convergenceDetection::execute()
160 | {
161 |     forces::execute();
162 | 
163 |     if (!porousObjects_.empty())
164 |     {
165 |         unsigned porousCount = 0;
166 |         for (surfaceFieldValue *sfv : porousObjects_)
167 |         {
168 |             sfv->write();
169 |             scalar area = sfv->getResult<scalar>("areaNormalIntegrate(" + porousNames_[porousCount] + ",U)");
170 | 
171 |             convergenceData_[porousNames_[porousCount]].push_back(area);
172 |             porousCount++;
173 |         }
174 |     }
175 | 
176 |     if (!rotatingObjects_.empty())
177 |     {
178 |         unsigned roCount = 0;
179 |         for (forces *f : rotatingObjects_)
180 |         {
181 |             f->calcForcesMoments();
182 |             const vector forces = f->forceEff();
183 | 
184 |             const double thrust = coordSysPtrC_->localVector(forces)[0];
185 | 
186 |             convergenceData_[rotatingNames_[roCount]].push_back(thrust);
187 |             roCount++;
188 |         }
189 |     }
190 | 
191 |     const vector sumForce = forces::forceEff();
192 | 
193 |     const double totalForce = sqrt(pow(sumForce[0], 2) + pow(sumForce[1], 2) + pow(sumForce[2], 2));
194 | 
195 |     convergenceData_["forces"].push_back(totalForce);
196 | 
197 |     currentIteration_ = time().value();
198 | 
199 |     // wait for a few iterations before starting gradient calculation
200 |     if (currentIteration_ >= 5)
201 |     {
202 | 
203 |         std::map<std::string, double> caclculatedGradient = calculateGradient();
204 |         for (const auto &cd : caclculatedGradient)
205 |         {
206 |             gradData_[cd.first].push_back(cd.second);
207 |         }
208 |     }
209 | 
210 |     // need few iterations before starting calculation
211 |     if (currentIteration_ >= iterationMinConvergence_)
212 |     {
213 |         if (!convergenceFound_)
214 |         {
215 |             convergenceEvaluation();
216 |         }
217 |         // Start to check at iterationMinAveraging to avoid calculate each iteration
218 |         if (currentIteration_ >= iterationMinAveraging_ &&
219 |             !simulationFinished_ &&
220 |             convergenceFound_)
221 |         {
222 |             std::map<std::string, double> cmg(convergenceMaxGradient());
223 | 
224 |             bool shouldBeKickedOut = std::any_of(cmg.begin(), cmg.end(), [this](const auto &cmg)
225 |                                                  { return cmg.second >= thresholdConvergence_; });
226 | 
227 |             if ((shouldBeKickedOut && !forcedConvergence_) &&
228 |                 (currentIteration_ < iterationMaxConvergence_))
229 |             {
230 |                 stopAveraging();
231 |             }
232 |             std::map<std::string, double> caclculatedGradientAveraging = calculateGradientAveraging();
233 |             for (const auto &c : caclculatedGradientAveraging)
234 |             {
235 |                 gradDataAveraging_[c.first].push_back(c.second);
236 |             }
237 |             isExploded();
238 |             isFinished();
239 |         }
240 |     }
241 | 
242 |     return true;
243 | }
244 | 
245 | bool Foam::functionObjects::convergenceDetection::end()
246 | {
247 |     return true;
248 | }
249 | 
250 | bool Foam::functionObjects::convergenceDetection::write()
251 | {
252 |     if (writeToFile())
253 |     {
254 | 
255 |         createDataFile();
256 |         writeDataFile(totalForceFilePtr_(), convergenceData_["forces"].back());
257 |         if (currentIteration_ >= 5)
258 |         {
259 |             writeDataFile(gradientFilePtr_(), gradData_["forces"].back());
260 |         }
261 |         if (convergenceFound_)
262 |         {
263 |             writeDataFile(gradientAveragedFilePtr_(), gradDataAveraging_["forces"].back());
264 |         }
265 |         forces::write();
266 |     }
267 |     return true;
268 | }
269 | 
270 | // * * * * * * * * * * * * * * * Protected Functions  * * * * * * * * * * * * * //
271 | 
272 | void Foam::functionObjects::convergenceDetection::createDataFile()
273 | {
274 |     if (!totalForceFilePtr_.valid())
275 |     {
276 |         totalForceFilePtr_ = createFile("totalForce");
277 |         writeDataFileHeader("totalForce", "total (x,y,z)", totalForceFilePtr_());
278 |     }
279 | 
280 |     if (!gradientFilePtr_.valid())
281 |     {
282 |         gradientFilePtr_ = createFile("gradient");
283 |         writeDataFileHeader("Gradient", "Gradient", gradientFilePtr_());
284 |     }
285 | 
286 |     if (!gradientAveragedFilePtr_.valid())
287 |     {
288 |         gradientAveragedFilePtr_ = createFile("gradientAveraged");
289 |         writeDataFileHeader("GradientAveraged", "GradientAveraged", gradientAveragedFilePtr_());
290 |     }
291 | }
292 | 
293 | void Foam::functionObjects::convergenceDetection::writeDataFileHeader(
294 |     const word &header,
295 |     const word &tabbedName,
296 |     OFstream &os) const
297 | {
298 |     writeHeader(os, header);
299 |     writeHeader(os, "");
300 |     writeCommented(os, "Time");
301 |     writeTabbed(os, tabbedName);
302 | 
303 |     os << endl;
304 | }
305 | 
306 | void Foam::functionObjects::convergenceDetection::writeDataFile(
307 |     OFstream &os, double &value) const
308 | {
309 |     writeCurrentTime(os);
310 | 
311 |     writeValue(os, value);
312 | 
313 |     os << endl;
314 | }
315 | 
316 | bool Foam::functionObjects::convergenceDetection::reachedMaxIterations()
317 | {
318 |     return currentIteration_ >= (iterationMaxConvergence_ + iterationMaxAveraging_);
319 | }
320 | 
321 | bool Foam::functionObjects::convergenceDetection::minIterationsForAveraging()
322 | {
323 |     return currentIteration_ >= static_cast<int>(1.1 * averagingStartedAt_) &&
324 |            currentIteration_ >= static_cast<int>(iterationMinAveraging_ + averagingStartedAt_);
325 | }
326 | 
327 | bool Foam::functionObjects::convergenceDetection::isAveraged()
328 | {
329 |     std::map<std::string, double> amg = averagingMaxGradient();
330 | 
331 |     bool allDataAveragedEnough = std::all_of(amg.begin(), amg.end(), [this](const auto &amg)
332 |                                              { return amg.second < thresholdAveraging_; });
333 | 
334 |     bool averagingMaxGradientGtZero = std::all_of(amg.begin(), amg.end(), [](const auto &amg)
335 |                                                   { return amg.second > 0.0; });
336 |     return allDataAveragedEnough &&
337 |            averagingMaxGradientGtZero &&
338 |            currentIteration_ > static_cast<int>(1.25 * averagingStartedAt_) &&
339 |            !simulationFinished_;
340 | }
341 | 
342 | void Foam::functionObjects::convergenceDetection::isFinished()
343 | {
344 |     if ((isAveraged() ||
345 |          reachedMaxIterations()) &&
346 |         minIterationsForAveraging())
347 |     {
348 |         std::map<std::string, double> amg = averagingMaxGradient();
349 |         Info << "###########" << endl;
350 |         Info << "Simulation should stop!!!!" << endl;
351 |         for (auto const &a : amg)
352 |         {
353 |             Info << "Gradient of " << a.first << ": " << a.second << endl;
354 |         }
355 |         Info << "Condition for averaging: " << thresholdAveraging_ << endl;
356 |         Info << "###########" << endl;
357 | 
358 |         time().stopAt(Time::saWriteNow);
359 |         toggleAveraging(false);
360 |         simulationFinished_ = true;
361 |     }
362 | }
363 | 
364 | void Foam::functionObjects::convergenceDetection::stopAveraging()
365 | {
366 |     convergenceFound_ = false;
367 |     toggleAveraging(false);
368 |     gradDataAveraging_.clear();
369 |     if (exists(time().globalPath() + "/averaging"))
370 |     {
371 |         rm(time().globalPath() + "/averaging");
372 |     }
373 |     Info << "## Getting out of averaging ###" << endl;
374 | }
375 | 
376 | void Foam::functionObjects::convergenceDetection::isExploded()
377 | {
378 |     bool anyNormalizedMeanDataGtZero = std::any_of(normalizedDataMeanConverged_.begin(), normalizedDataMeanConverged_.end(), [](const auto &ndmc)
379 |                                                    { return ndmc.second > 0; });
380 | 
381 |     if (anyNormalizedMeanDataGtZero && convergenceFound_)
382 |     {
383 |         double test1 = normalizedDataMeanConverged_["forces"] / convergenceStabilityFactor_;
384 |         double test2 = normalizedDataMeanConverged_["forces"] * convergenceStabilityFactor_;
385 |         double lastIterationForces = convergenceData_["forces"].back();
386 | 
387 |         if (lastIterationForces < test1 or lastIterationForces > test2)
388 |         {
389 |             if (Pstream::master())
390 |             {
391 |                 FatalErrorInFunction
392 |                     << "Forces Exploded, mean force value converged: " << lastIterationForces << nl
393 |                     << exit(FatalError);
394 |             }
395 |         }
396 |     }
397 | }
398 | 
399 | void Foam::functionObjects::convergenceDetection::convergenceEvaluation()
400 | {
401 |     std::map<std::string, double> cmg(convergenceMaxGradient());
402 | 
403 |     bool allDataConverged = std::all_of(cmg.begin(), cmg.end(), [this](const auto &cmg)
404 |                                         { return cmg.second < thresholdConvergence_; });
405 | 
406 |     if ((allDataConverged &&
407 |          currentIteration_ >= iterationMinConvergence_ &&
408 |          !convergenceFound_) ||
409 |         (currentIteration_ >= iterationMaxConvergence_ &&
410 |          !convergenceFound_))
411 |     {
412 |         convergenceFound_ = true;
413 |         if (currentIteration_ >= iterationMaxConvergence_)
414 |         {
415 |             forcedConvergence_ = true;
416 |         }
417 |         word forcedConvergence = forcedConvergence_ ? "Forced " : "";
418 |         Info << "#####################################" << endl;
419 |         Info << forcedConvergence << "Convergence Found" << endl;
420 |         Info << "#####################################" << endl;
421 |         for (auto const &c : cmg)
422 |         {
423 |             Info << "Gradient of " << c.first << ": " << c.second << endl;
424 |         }
425 |         Info << "Condition for convergence: " << thresholdConvergence_ << endl;
426 |         for (auto const &c : cmg)
427 |         {
428 |             Info << "Condition for " << c.first << "is : " << (c.second < thresholdConvergence_) << endl;
429 |         }
430 | 
431 |         averagingStartedAt_ = currentIteration_;
432 | 
433 |         int windowDataNormalization = static_cast<int>(currentIteration_ * windowNormalization_);
434 | 
435 |         std::map<std::string, std::vector<double>> normalizedData;
436 | 
437 |         for (auto const &d : convergenceData_)
438 |         {
439 |             normalizedData[d.first].insert(normalizedData[d.first].end(), d.second.end() - windowDataNormalization, d.second.end());
440 |         }
441 | 
442 |         normalizedDataMeanConverged_ = meanValue(normalizedData);
443 | 
444 |         OFstream os(time().globalPath() + "/averaging");
445 |         os << averagingStartedAt_ << endl;
446 | 
447 |         toggleAveraging(true);
448 |     }
449 | }
450 | 
451 | void Foam::functionObjects::convergenceDetection::toggleAveraging(bool toggle)
452 | {
453 |     IOdictionary averaging(IOobject(
454 |         "averaging",
455 |         time().caseSystem(),
456 |         obr_,
457 |         IOobject::MUST_READ_IF_MODIFIED,
458 |         IOobject::AUTO_WRITE));
459 |     averaging.subDict("fieldAverage1").set("timeStart", toggle ? currentIteration_ : 0);
460 |     averaging.subDict("fieldAverage1").set("enabled", toggle);
461 |     averaging.regIOobject::write();
462 | }
463 | 
464 | std::map<std::string, std::vector<double>> Foam::functionObjects::convergenceDetection::divideData(std::map<std::string, double> dataMean)
465 | {
466 |     std::map<std::string, std::vector<double>> dividedData;
467 | 
468 |     for (const auto &cd : convergenceData_)
469 |     {
470 |         for (auto itr : cd.second)
471 |             dividedData[cd.first].push_back(itr / dataMean[cd.first]);
472 |     }
473 | 
474 |     return dividedData;
475 | }
476 | 
477 | std::map<std::string, double> Foam::functionObjects::convergenceDetection::meanValue(std::map<std::string, std::vector<double>> normalizedData)
478 | {
479 |     std::map<std::string, double> meanData;
480 | 
481 |     for (const auto &nd : normalizedData)
482 |     {
483 |         double sum = 0.0;
484 |         for (auto itr : nd.second)
485 |             sum += itr;
486 |         meanData[nd.first] = sum / nd.second.size();
487 |     }
488 | 
489 |     return meanData; // for transient change this
490 | }
491 | 
492 | std::map<std::string, double> Foam::functionObjects::convergenceDetection::calculateGradientAveraging()
493 | {
494 |     int averagingSize = currentIteration_ - averagingStartedAt_;
495 |     std::map<std::string, double> gradient;
496 | 
497 |     // allow some data to come in
498 |     if (averagingSize >= 5)
499 |     {
500 |         double maxIterationNormalized = static_cast<double>(currentIteration_) / static_cast<double>(averagingStartedAt_);
501 | 
502 |         convergenceNormalizedAveraging_ = divideData(normalizedDataMeanConverged_);
503 | 
504 |         double start = 1 + (maxIterationNormalized / averagingSize);
505 |         double end = maxIterationNormalized + maxIterationNormalized / averagingSize;
506 |         double step = (maxIterationNormalized - 1) / averagingSize;
507 | 
508 |         std::vector<double> xAxisNormalized = arange(start, end, step);
509 | 
510 |         std::map<std::string, std::vector<double>> windowDataForGradient;
511 | 
512 |         int windowDataNormalization = static_cast<int>(xAxisNormalized.size() * windowGradientAveraging_);
513 | 
514 |         for (auto const &c : convergenceNormalizedAveraging_)
515 |         {
516 |             windowDataForGradient[c.first].insert(windowDataForGradient[c.first].end(), c.second.end() - windowDataNormalization, c.second.end());
517 |         }
518 | 
519 |         std::vector<double> windowXAxisForGradient(xAxisNormalized.end() - windowDataNormalization, xAxisNormalized.end());
520 | 
521 |         if (windowDataForGradient["forces"].size() < 5)
522 |         {
523 |             for (const auto &d : windowDataForGradient)
524 |             {
525 |                 gradient[d.first] = 0.0;
526 |             }
527 |             return gradient;
528 |         }
529 | 
530 |         for (const auto &d : windowDataForGradient)
531 |         {
532 |             gradient[d.first] = polyfit(windowXAxisForGradient, d.second, 1, {0});
533 |         }
534 | 
535 |         return gradient;
536 |     }
537 |     for (const auto &n : normalizedDataMeanConverged_)
538 |     {
539 |         gradient[n.first] = 0.0;
540 |     }
541 |     return gradient;
542 | }
543 | 
544 | std::map<std::string, double> Foam::functionObjects::convergenceDetection::calculateGradient()
545 | {
546 |     int windowDataNormalization = static_cast<int>(currentIteration_ * windowNormalization_);
547 |     int windowDataGradient = static_cast<int>(currentIteration_ * windowGradient_);
548 | 
549 |     std::map<std::string, std::vector<double>> normalizedData;
550 | 
551 |     for (auto const &d : convergenceData_)
552 |     {
553 |         normalizedData[d.first].insert(normalizedData[d.first].end(), d.second.end() - windowDataNormalization, d.second.end());
554 |     }
555 | 
556 |     std::map<std::string, double> dataMean = meanValue(normalizedData);
557 | 
558 |     dataNormalized_ = divideData(dataMean);
559 | 
560 |     // take this into account for transient
561 |     double start = 1.0f / currentIteration_;
562 |     double end = 1.0f + 1.0f / currentIteration_;
563 |     double step = 1.0f / currentIteration_;
564 | 
565 |     std::vector<double> xAxisNormalized = arange(start, end, step);
566 | 
567 |     std::map<std::string, std::vector<double>> windowDataForGradient;
568 | 
569 |     for (auto const &d : dataNormalized_)
570 |     {
571 |         windowDataForGradient[d.first].insert(windowDataForGradient[d.first].end(), d.second.end() - windowDataGradient, d.second.end());
572 |     }
573 | 
574 |     std::vector<double> windowXAxisForGradient(xAxisNormalized.end() - windowDataGradient, xAxisNormalized.end());
575 | 
576 |     std::map<std::string, double> gradient;
577 | 
578 |     for (const auto &data : windowDataForGradient)
579 |     {
580 |         gradient[data.first] = polyfit(windowXAxisForGradient, data.second, 1, {0});
581 |     }
582 | 
583 |     return gradient;
584 | }
585 | 
586 | // DRY
587 | std::map<std::string, double> Foam::functionObjects::convergenceDetection::convergenceMaxGradient()
588 | {
589 |     int evaluationWindow = static_cast<int>(windowEvaluation_ * gradData_["forces"].size());
590 |     std::map<std::string, std::vector<double>> dataForEvaluation;
591 |     std::map<std::string, double> maxGradient;
592 |     std::map<std::string, double> defaultGradient;
593 | 
594 |     for (const auto &gd : gradData_)
595 |     {
596 |         dataForEvaluation[gd.first].insert(dataForEvaluation[gd.first].end(), gd.second.end() - evaluationWindow, gd.second.end());
597 |     }
598 | 
599 |     if (dataForEvaluation["forces"].size() > 0)
600 |     {
601 |         for (const auto &afe : dataForEvaluation)
602 |         {
603 |             double maxValue = *std::max_element(afe.second.begin(), afe.second.end());
604 |             double minValue = *std::min_element(afe.second.begin(), afe.second.end());
605 | 
606 |             maxGradient[afe.first] = max(maxValue, fabs(minValue));
607 |         }
608 | 
609 |         return maxGradient;
610 |     }
611 |     for (const auto &gd : gradData_)
612 |     {
613 |         defaultGradient[gd.first] = 1.0;
614 |     }
615 | 
616 |     return defaultGradient;
617 | }
618 | 
619 | // DRY
620 | std::map<std::string, double> Foam::functionObjects::convergenceDetection::averagingMaxGradient()
621 | {
622 |     int evaluationWindow = static_cast<int>(
623 |         windowEvaluationAveraging_ * gradDataAveraging_["forces"].size());
624 | 
625 |     std::map<std::string, std::vector<double>> dataForEvaluation;
626 |     std::map<std::string, double> maxGradient;
627 |     std::map<std::string, double> defaultGradient;
628 | 
629 |     for (const auto &gd : gradDataAveraging_)
630 |     {
631 |         dataForEvaluation[gd.first].insert(dataForEvaluation[gd.first].end(), gd.second.end() - evaluationWindow, gd.second.end());
632 |     }
633 | 
634 |     if (dataForEvaluation["forces"].size() > 0)
635 |     {
636 |         for (const auto &afe : dataForEvaluation)
637 |         {
638 |             double maxValue = *std::max_element(afe.second.begin(), afe.second.end());
639 |             double minValue = *std::min_element(afe.second.begin(), afe.second.end());
640 | 
641 |             maxGradient[afe.first] = max(maxValue, fabs(minValue));
642 |         }
643 | 
644 |         return maxGradient;
645 |     }
646 |     for (const auto &gd : gradDataAveraging_)
647 |     {
648 |         defaultGradient[gd.first] = 1.0;
649 |     }
650 | 
651 |     return defaultGradient;
652 | }
653 | 
654 | std::vector<double> Foam::functionObjects::convergenceDetection::arange(double start, double stop, double step)
655 | {
656 |     std::vector<double> values;
657 |     for (double value = start; value < stop; value += step)
658 |         values.push_back(value);
659 |     return values;
660 | }
661 | // https://gist.github.com/chrisengelsma/108f7ab0a746323beaaf7d6634cf4add
662 | double Foam::functionObjects::convergenceDetection::polyfit(
663 |     const std::vector<double> x,
664 |     const std::vector<double> y,
665 |     const int order,
666 |     std::vector<double> coeffs)
667 | {
668 |     // The size of xValues and yValues should be same
669 |     if (x.size() != y.size())
670 |     {
671 |         throw std::runtime_error("The size of x & y arrays are different");
672 |         return {};
673 |     }
674 |     // The size of xValues and yValues cannot be 0, should not happen
675 |     if (x.size() == 0 || y.size() == 0)
676 |     {
677 |         throw std::runtime_error("The size of x or y arrays is 0");
678 |         return {};
679 |     }
680 | 
681 |     size_t N = x.size();
682 |     int n = order;
683 |     int np1 = n + 1;
684 |     int np2 = n + 2;
685 |     int tnp1 = 2 * n + 1;
686 |     double tmp;
687 | 
688 |     // X = vector that stores values of sigma(xi^2n)
689 |     std::vector<double> X(tnp1);
690 |     for (int i = 0; i < tnp1; ++i)
691 |     {
692 |         X[i] = 0;
693 |         for (size_t j = 0; j < N; ++j)
694 |             X[i] += static_cast<double>(pow(x[j], i));
695 |     }
696 | 
697 |     // a = vector to store final coefficients.
698 |     std::vector<double> a(np1);
699 | 
700 |     // B = normal augmented matrix that stores the equations.
701 |     std::vector<std::vector<double>> B(np1, std::vector<double>(np2, 0));
702 | 
703 |     for (int i = 0; i <= n; ++i)
704 |         for (int j = 0; j <= n; ++j)
705 |             B[i][j] = X[i + j];
706 | 
707 |     // Y = vector to store values of sigma(xi^n * yi)
708 |     std::vector<double> Y(np1);
709 |     for (int i = 0; i < np1; ++i)
710 |     {
711 |         Y[i] = static_cast<double>(0);
712 |         for (size_t j = 0; j < N; ++j)
713 |         {
714 |             Y[i] += static_cast<double>(pow(x[j], i) * y[j]);
715 |         }
716 |     }
717 | 
718 |     // Load values of Y as last column of B
719 |     for (int i = 0; i <= n; ++i)
720 |         B[i][np1] = Y[i];
721 | 
722 |     n += 1;
723 |     int nm1 = n - 1;
724 | 
725 |     // Pivotisation of the B matrix.
726 |     for (int i = 0; i < n; ++i)
727 |         for (int k = i + 1; k < n; ++k)
728 |             if (B[i][i] < B[k][i])
729 |                 for (int j = 0; j <= n; ++j)
730 |                 {
731 |                     tmp = B[i][j];
732 |                     B[i][j] = B[k][j];
733 |                     B[k][j] = tmp;
734 |                 }
735 | 
736 |     // Performs the Gaussian elimination.
737 |     // (1) Make all elements below the pivot equals to zero
738 |     //     or eliminate the variable.
739 |     for (int i = 0; i < nm1; ++i)
740 |         for (int k = i + 1; k < n; ++k)
741 |         {
742 |             double t = B[k][i] / B[i][i];
743 |             for (int j = 0; j <= n; ++j)
744 |                 B[k][j] -= t * B[i][j]; // (1)
745 |         }
746 | 
747 |     // Back substitution.
748 |     // (1) Set the variable as the rhs of last equation
749 |     // (2) Subtract all lhs values except the target coefficient.
750 |     // (3) Divide rhs by coefficient of variable being calculated.
751 |     for (int i = nm1; i >= 0; --i)
752 |     {
753 |         a[i] = B[i][n]; // (1)
754 |         for (int j = 0; j < n; ++j)
755 |             if (j != i)
756 |                 a[i] -= B[i][j] * a[j]; // (2)
757 |         a[i] /= B[i][i];                // (3)
758 |     }
759 | 
760 |     coeffs.resize(a.size());
761 |     for (size_t i = 0; i < a.size(); ++i)
762 |         coeffs[i] = a[i];
763 | 
764 |     return static_cast<double>(coeffs[1]);
765 | }
766 | 
767 | // ************************************************************************* //


--------------------------------------------------------------------------------
/LICENSE:
--------------------------------------------------------------------------------
  1 |                     GNU GENERAL PUBLIC LICENSE
  2 |                        Version 3, 29 June 2007
  3 | 
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230 |     d) If the work has interactive user interfaces, each must display
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235 |   A compilation of a covered work with other separate and independent
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245 |   6. Conveying Non-Source Forms.
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247 |   You may convey a covered work in object code form under the terms
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275 |     d) Convey the object code by offering access from a designated
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288 |     e) Convey the object code using peer-to-peer transmission, provided
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290 |     Source of the work are being offered to the general public at no
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318 |   If you convey an object code work under this section in, or with, or
319 | specifically for use in, a User Product, and the conveying occurs as
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338 | in accord with this section must be in a format that is publicly
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342 | 
343 |   7. Additional Terms.
344 | 
345 |   "Additional permissions" are terms that supplement the terms of this
346 | License by making exceptions from one or more of its conditions.
347 | Additional permissions that are applicable to the entire Program shall
348 | be treated as though they were included in this License, to the extent
349 | that they are valid under applicable law.  If additional permissions
350 | apply only to part of the Program, that part may be used separately
351 | under those permissions, but the entire Program remains governed by
352 | this License without regard to the additional permissions.
353 | 
354 |   When you convey a copy of a covered work, you may at your option
355 | remove any additional permissions from that copy, or from any part of
356 | it.  (Additional permissions may be written to require their own
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361 |   Notwithstanding any other provision of this License, for material you
362 | add to a covered work, you may (if authorized by the copyright holders of
363 | that material) supplement the terms of this License with terms:
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365 |     a) Disclaiming warranty or limiting liability differently from the
366 |     terms of sections 15 and 16 of this License; or
367 | 
368 |     b) Requiring preservation of specified reasonable legal notices or
369 |     author attributions in that material or in the Appropriate Legal
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388 |   All other non-permissive additional terms are considered "further
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390 | received it, or any part of it, contains a notice stating that it is
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393 | a further restriction but permits relicensing or conveying under this
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398 |   If you add terms to a covered work in accord with this section, you
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403 |   Additional terms, permissive or non-permissive, may be stated in the
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405 | the above requirements apply either way.
406 | 
407 |   8. Termination.
408 | 
409 |   You may not propagate or modify a covered work except as expressly
410 | provided under this License.  Any attempt otherwise to propagate or
411 | modify it is void, and will automatically terminate your rights under
412 | this License (including any patent licenses granted under the third
413 | paragraph of section 11).
414 | 
415 |   However, if you cease all violation of this License, then your
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421 | 
422 |   Moreover, your license from a particular copyright holder is
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425 | received notice of violation of this License (for any work) from that
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427 | your receipt of the notice.
428 | 
429 |   Termination of your rights under this section does not terminate the
430 | licenses of parties who have received copies or rights from you under
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432 | reinstated, you do not qualify to receive new licenses for the same
433 | material under section 10.
434 | 
435 |   9. Acceptance Not Required for Having Copies.
436 | 
437 |   You are not required to accept this License in order to receive or
438 | run a copy of the Program.  Ancillary propagation of a covered work
439 | occurring solely as a consequence of using peer-to-peer transmission
440 | to receive a copy likewise does not require acceptance.  However,
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442 | modify any covered work.  These actions infringe copyright if you do
443 | not accept this License.  Therefore, by modifying or propagating a
444 | covered work, you indicate your acceptance of this License to do so.
445 | 
446 |   10. Automatic Licensing of Downstream Recipients.
447 | 
448 |   Each time you convey a covered work, the recipient automatically
449 | receives a license from the original licensors, to run, modify and
450 | propagate that work, subject to this License.  You are not responsible
451 | for enforcing compliance by third parties with this License.
452 | 
453 |   An "entity transaction" is a transaction transferring control of an
454 | organization, or substantially all assets of one, or subdividing an
455 | organization, or merging organizations.  If propagation of a covered
456 | work results from an entity transaction, each party to that
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462 | 
463 |   You may not impose any further restrictions on the exercise of the
464 | rights granted or affirmed under this License.  For example, you may
465 | not impose a license fee, royalty, or other charge for exercise of
466 | rights granted under this License, and you may not initiate litigation
467 | (including a cross-claim or counterclaim in a lawsuit) alleging that
468 | any patent claim is infringed by making, using, selling, offering for
469 | sale, or importing the Program or any portion of it.
470 | 
471 |   11. Patents.
472 | 
473 |   A "contributor" is a copyright holder who authorizes use under this
474 | License of the Program or a work on which the Program is based.  The
475 | work thus licensed is called the contributor's "contributor version".
476 | 
477 |   A contributor's "essential patent claims" are all patent claims
478 | owned or controlled by the contributor, whether already acquired or
479 | hereafter acquired, that would be infringed by some manner, permitted
480 | by this License, of making, using, or selling its contributor version,
481 | but do not include claims that would be infringed only as a
482 | consequence of further modification of the contributor version.  For
483 | purposes of this definition, "control" includes the right to grant
484 | patent sublicenses in a manner consistent with the requirements of
485 | this License.
486 | 
487 |   Each contributor grants you a non-exclusive, worldwide, royalty-free
488 | patent license under the contributor's essential patent claims, to
489 | make, use, sell, offer for sale, import and otherwise run, modify and
490 | propagate the contents of its contributor version.
491 | 
492 |   In the following three paragraphs, a "patent license" is any express
493 | agreement or commitment, however denominated, not to enforce a patent
494 | (such as an express permission to practice a patent or covenant not to
495 | sue for patent infringement).  To "grant" such a patent license to a
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497 | patent against the party.
498 | 
499 |   If you convey a covered work, knowingly relying on a patent license,
500 | and the Corresponding Source of the work is not available for anyone
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503 | then you must either (1) cause the Corresponding Source to be so
504 | available, or (2) arrange to deprive yourself of the benefit of the
505 | patent license for this particular work, or (3) arrange, in a manner
506 | consistent with the requirements of this License, to extend the patent
507 | license to downstream recipients.  "Knowingly relying" means you have
508 | actual knowledge that, but for the patent license, your conveying the
509 | covered work in a country, or your recipient's use of the covered work
510 | in a country, would infringe one or more identifiable patents in that
511 | country that you have reason to believe are valid.
512 | 
513 |   If, pursuant to or in connection with a single transaction or
514 | arrangement, you convey, or propagate by procuring conveyance of, a
515 | covered work, and grant a patent license to some of the parties
516 | receiving the covered work authorizing them to use, propagate, modify
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518 | you grant is automatically extended to all recipients of the covered
519 | work and works based on it.
520 | 
521 |   A patent license is "discriminatory" if it does not include within
522 | the scope of its coverage, prohibits the exercise of, or is
523 | conditioned on the non-exercise of one or more of the rights that are
524 | specifically granted under this License.  You may not convey a covered
525 | work if you are a party to an arrangement with a third party that is
526 | in the business of distributing software, under which you make payment
527 | to the third party based on the extent of your activity of conveying
528 | the work, and under which the third party grants, to any of the
529 | parties who would receive the covered work from you, a discriminatory
530 | patent license (a) in connection with copies of the covered work
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533 | contain the covered work, unless you entered into that arrangement,
534 | or that patent license was granted, prior to 28 March 2007.
535 | 
536 |   Nothing in this License shall be construed as excluding or limiting
537 | any implied license or other defenses to infringement that may
538 | otherwise be available to you under applicable patent law.
539 | 
540 |   12. No Surrender of Others' Freedom.
541 | 
542 |   If conditions are imposed on you (whether by court order, agreement or
543 | otherwise) that contradict the conditions of this License, they do not
544 | excuse you from the conditions of this License.  If you cannot convey a
545 | covered work so as to satisfy simultaneously your obligations under this
546 | License and any other pertinent obligations, then as a consequence you may
547 | not convey it at all.  For example, if you agree to terms that obligate you
548 | to collect a royalty for further conveying from those to whom you convey
549 | the Program, the only way you could satisfy both those terms and this
550 | License would be to refrain entirely from conveying the Program.
551 | 
552 |   13. Use with the GNU Affero General Public License.
553 | 
554 |   Notwithstanding any other provision of this License, you have
555 | permission to link or combine any covered work with a work licensed
556 | under version 3 of the GNU Affero General Public License into a single
557 | combined work, and to convey the resulting work.  The terms of this
558 | License will continue to apply to the part which is the covered work,
559 | but the special requirements of the GNU Affero General Public License,
560 | section 13, concerning interaction through a network will apply to the
561 | combination as such.
562 | 
563 |   14. Revised Versions of this License.
564 | 
565 |   The Free Software Foundation may publish revised and/or new versions of
566 | the GNU General Public License from time to time.  Such new versions will
567 | be similar in spirit to the present version, but may differ in detail to
568 | address new problems or concerns.
569 | 
570 |   Each version is given a distinguishing version number.  If the
571 | Program specifies that a certain numbered version of the GNU General
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573 | option of following the terms and conditions either of that numbered
574 | version or of any later version published by the Free Software
575 | Foundation.  If the Program does not specify a version number of the
576 | GNU General Public License, you may choose any version ever published
577 | by the Free Software Foundation.
578 | 
579 |   If the Program specifies that a proxy can decide which future
580 | versions of the GNU General Public License can be used, that proxy's
581 | public statement of acceptance of a version permanently authorizes you
582 | to choose that version for the Program.
583 | 
584 |   Later license versions may give you additional or different
585 | permissions.  However, no additional obligations are imposed on any
586 | author or copyright holder as a result of your choosing to follow a
587 | later version.
588 | 
589 |   15. Disclaimer of Warranty.
590 | 
591 |   THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
592 | APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
593 | HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
594 | OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
595 | THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
596 | PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
597 | IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
598 | ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
599 | 
600 |   16. Limitation of Liability.
601 | 
602 |   IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
603 | WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
604 | THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
605 | GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
606 | USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
607 | DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
608 | PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
609 | EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
610 | SUCH DAMAGES.
611 | 
612 |   17. Interpretation of Sections 15 and 16.
613 | 
614 |   If the disclaimer of warranty and limitation of liability provided
615 | above cannot be given local legal effect according to their terms,
616 | reviewing courts shall apply local law that most closely approximates
617 | an absolute waiver of all civil liability in connection with the
618 | Program, unless a warranty or assumption of liability accompanies a
619 | copy of the Program in return for a fee.
620 | 
621 |                      END OF TERMS AND CONDITIONS
622 | 
623 |             How to Apply These Terms to Your New Programs
624 | 
625 |   If you develop a new program, and you want it to be of the greatest
626 | possible use to the public, the best way to achieve this is to make it
627 | free software which everyone can redistribute and change under these terms.
628 | 
629 |   To do so, attach the following notices to the program.  It is safest
630 | to attach them to the start of each source file to most effectively
631 | state the exclusion of warranty; and each file should have at least
632 | the "copyright" line and a pointer to where the full notice is found.
633 | 
634 |     convergence-detection
635 |     Copyright (C) 2022  airshaper
636 | 
637 |     This program is free software: you can redistribute it and/or modify
638 |     it under the terms of the GNU General Public License as published by
639 |     the Free Software Foundation, either version 3 of the License, or
640 |     (at your option) any later version.
641 | 
642 |     This program is distributed in the hope that it will be useful,
643 |     but WITHOUT ANY WARRANTY; without even the implied warranty of
644 |     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
645 |     GNU General Public License for more details.
646 | 
647 |     You should have received a copy of the GNU General Public License
648 |     along with this program.  If not, see <https://www.gnu.org/licenses/>.
649 | 
650 | Also add information on how to contact you by electronic and paper mail.
651 | 
652 |   If the program does terminal interaction, make it output a short
653 | notice like this when it starts in an interactive mode:
654 | 
655 |     <program>  Copyright (C) 2022  airshaper
656 |     This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
657 |     This is free software, and you are welcome to redistribute it
658 |     under certain conditions; type `show c' for details.
659 | 
660 | The hypothetical commands `show w' and `show c' should show the appropriate
661 | parts of the General Public License.  Of course, your program's commands
662 | might be different; for a GUI interface, you would use an "about box".
663 | 
664 |   You should also get your employer (if you work as a programmer) or school,
665 | if any, to sign a "copyright disclaimer" for the program, if necessary.
666 | For more information on this, and how to apply and follow the GNU GPL, see
667 | <https://www.gnu.org/licenses/>.
668 | 
669 |   The GNU General Public License does not permit incorporating your program
670 | into proprietary programs.  If your program is a subroutine library, you
671 | may consider it more useful to permit linking proprietary applications with
672 | the library.  If this is what you want to do, use the GNU Lesser General
673 | Public License instead of this License.  But first, please read
674 | <https://www.gnu.org/licenses/why-not-lgpl.html>.
675 | 


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