1 files changed, 177 insertions, 0 deletions
diff --git a/sccomp/source/solver/ParticelSwarmOptimization.hxx b/sccomp/source/solver/ParticelSwarmOptimization.hxx
new file mode 100644
index 000000000..ad1103309
--- /dev/null
+++ b/sccomp/source/solver/ParticelSwarmOptimization.hxx
@@ -0,0 +1,177 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ */
+
+#pragma once
+
+#include <vector>
+#include <random>
+#include <limits>
+
+struct Particle
+{
+    Particle(size_t nDimensionality)
+        : mVelocity(nDimensionality)
+        , mPosition(nDimensionality)
+        , mCurrentFitness(std::numeric_limits<float>::lowest())
+        , mBestPosition(nDimensionality)
+        , mBestFitness(std::numeric_limits<float>::lowest())
+    {
+    }
+
+    std::vector<double> mVelocity;
+
+    std::vector<double> mPosition;
+    double mCurrentFitness;
+
+    std::vector<double> mBestPosition;
+    double mBestFitness;
+};
+
+template <typename DataProvider> class ParticleSwarmOptimizationAlgorithm
+{
+private:
+    // inertia
+    static constexpr double constWeight = 0.729;
+    // cognitive coefficient
+    static constexpr double c1 = 1.49445;
+    // social  coefficient
+    static constexpr double c2 = 1.49445;
+
+    static constexpr double constAcceptedPrecision = 0.000000001;
+
+    DataProvider& mrDataProvider;
+
+    size_t mnNumOfParticles;
+
+    std::vector<Particle> maSwarm;
+
+    std::random_device maRandomDevice;
+    std::mt19937 maGenerator;
+    size_t mnDimensionality;
+
+    std::uniform_real_distribution<> maRandom01;
+
+    std::vector<double> maBestPosition;
+    double mfBestFitness;
+    int mnGeneration;
+    int mnLastChange;
+
+public:
+    ParticleSwarmOptimizationAlgorithm(DataProvider& rDataProvider, size_t nNumOfParticles)
+        : mrDataProvider(rDataProvider)
+        , mnNumOfParticles(nNumOfParticles)
+        , maGenerator(maRandomDevice())
+        , mnDimensionality(mrDataProvider.getDimensionality())
+        , maRandom01(0.0, 1.0)
+        , maBestPosition(mnDimensionality)
+        , mfBestFitness(std::numeric_limits<float>::lowest())
+        , mnGeneration(0)
+        , mnLastChange(0)
+    {
+    }
+
+    std::vector<double> const& getResult() { return maBestPosition; }
+
+    int getGeneration() { return mnGeneration; }
+
+    int getLastChange() { return mnLastChange; }
+
+    void initialize()
+    {
+        mnGeneration = 0;
+        mnLastChange = 0;
+        maSwarm.clear();
+
+        mfBestFitness = std::numeric_limits<float>::lowest();
+
+        maSwarm.reserve(mnNumOfParticles);
+        for (size_t i = 0; i < mnNumOfParticles; i++)
+        {
+            maSwarm.emplace_back(mnDimensionality);
+            Particle& rParticle = maSwarm.back();
+
+            mrDataProvider.initializeVariables(rParticle.mPosition, maGenerator);
+            mrDataProvider.initializeVariables(rParticle.mVelocity, maGenerator);
+
+            for (size_t k = 0; k < mnDimensionality; k++)
+            {
+                rParticle.mPosition[k] = mrDataProvider.clampVariable(k, rParticle.mPosition[k]);
+            }
+
+            rParticle.mCurrentFitness = mrDataProvider.calculateFitness(rParticle.mPosition);
+
+            for (size_t k = 0; k < mnDimensionality; k++)
+            {
+                rParticle.mPosition[k] = mrDataProvider.clampVariable(k, rParticle.mPosition[k]);
+            }
+
+            rParticle.mBestPosition.insert(rParticle.mBestPosition.begin(),
+                                           rParticle.mPosition.begin(), rParticle.mPosition.end());
+            rParticle.mBestFitness = rParticle.mCurrentFitness;
+
+            if (rParticle.mCurrentFitness > mfBestFitness)
+            {
+                mfBestFitness = rParticle.mCurrentFitness;
+                maBestPosition.insert(maBestPosition.begin(), rParticle.mPosition.begin(),
+                                      rParticle.mPosition.end());
+            }
+        }
+    }
+
+    bool next()
+    {
+        bool bBestChanged = false;
+
+        for (Particle& rParticle : maSwarm)
+        {
+            double fRandom1 = maRandom01(maGenerator);
+            double fRandom2 = maRandom01(maGenerator);
+
+            for (size_t k = 0; k < mnDimensionality; k++)
+            {
+                rParticle.mVelocity[k]
+                    = (constWeight * rParticle.mVelocity[k])
+                      + (c1 * fRandom1 * (rParticle.mBestPosition[k] - rParticle.mPosition[k]))
+                      + (c2 * fRandom2 * (maBestPosition[k] - rParticle.mPosition[k]));
+
+                mrDataProvider.clampVariable(k, rParticle.mVelocity[k]);
+
+                rParticle.mPosition[k] += rParticle.mVelocity[k];
+                rParticle.mPosition[k] = mrDataProvider.clampVariable(k, rParticle.mPosition[k]);
+            }
+
+            rParticle.mCurrentFitness = mrDataProvider.calculateFitness(rParticle.mPosition);
+
+            if (rParticle.mCurrentFitness > rParticle.mBestFitness)
+            {
+                rParticle.mBestFitness = rParticle.mCurrentFitness;
+                rParticle.mBestPosition.insert(rParticle.mBestPosition.begin(),
+                                               rParticle.mPosition.begin(),
+                                               rParticle.mPosition.end());
+            }
+
+            if (rParticle.mCurrentFitness > mfBestFitness)
+            {
+                if (std::abs(rParticle.mCurrentFitness - mfBestFitness) > constAcceptedPrecision)
+                {
+                    bBestChanged = true;
+                    mnLastChange = mnGeneration;
+                }
+                maBestPosition.insert(maBestPosition.begin(), rParticle.mPosition.begin(),
+                                      rParticle.mPosition.end());
+                mfBestFitness = rParticle.mCurrentFitness;
+            }
+        }
+        mnGeneration++;
+        return bBestChanged;
+    }
+};
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */