Game::EPEC::warmstart and Models::EPEC::readSolutionJSON

Warmstarting from existing solution

src/EPEC.cpp

@@ -197,7 +197,7 @@ int main(int argc, char **argv) {
   results << " ];" << to_string(stat.status) << ";[ " << PolyT.str() << "];"
           << stat.numVar << ";" << stat.numConstraints << ";" << stat.numNonZero
           << ";" << WallClockTime << ";" << realThreads << ";"
-          << to_string(epec.indicators) << "\n";
+          << to_string(epec.getIndicators()) << "\n";
   results.close();
 
   return EXIT_SUCCESS;

src/Games.cpp

@@ -1732,6 +1732,43 @@ bool Game::EPEC::computeNashEq(
   return foundNash;
 }
 
+bool Game::EPEC::warmstart(const arma::vec x, const arma::vec z) {
+
+  if (x.size() < this->getnVarinEPEC()) {
+    BOOST_LOG_TRIVIAL(error)
+        << "Exception in Game::EPEC::warmstart: number of variables "
+           "does not fit this instance.";
+    throw;
+  }
+  if (!this->finalized) {
+    BOOST_LOG_TRIVIAL(error)
+        << "Exception in Game::EPEC::warmstart: EPEC is not finalized.";
+    throw;
+  }
+  if (this->country_QP.front() == nullptr) {
+    BOOST_LOG_TRIVIAL(warning)
+        << "Game::EPEC::warmstart: Generating QP as of warmstart.";
+  }
+
+  this->sol_x = x;
+  std::vector<arma::vec> devns = std::vector<arma::vec>(this->nCountr);
+  std::vector<arma::vec> prevDevns = std::vector<arma::vec>(this->nCountr);
+  this->getAllDevns(devns, this->sol_x, prevDevns);
+  unsigned int addedPoly = this->addDeviatedPolyhedron(devns);
+  this->make_country_QP();
+
+  unsigned int c;
+  arma::vec devn;
+
+  if (this->isSolved(&c, &devn))
+    BOOST_LOG_TRIVIAL(warning) << "Exception in Game::EPEC::warmstart: "
+                                  "The loaded solution is optimal.";
+  else
+    BOOST_LOG_TRIVIAL(warning)
+        << "Exception in Game::EPEC::warmstart: "
+           "The loaded solution is NOT optimal. Trying to repair.";
+}
+
 void Game::EPEC::findNashEq() {
   /**
    * @brief Computes Nash equilibrium using the algorithm set in

src/Models.cpp

@@ -1204,6 +1204,47 @@ void Models::EPEC::writeSolutionJSON(string filename, const arma::vec x,
   file << s.GetString();
 }
 
+void Models::EPEC::readSolutionJSON(string filename) {
+  /**
+   * @brief Reads the solution file and load it in the current EPEC instance
+   * **/
+  ifstream ifs(filename + ".json");
+  if (ifs.good()) {
+    IStreamWrapper isw(ifs);
+    Document d;
+    try {
+      d.ParseStream(isw);
+      const Value &x = d["Solution"].GetObject()["x"];
+      const Value &z = d["Solution"].GetObject()["z"];
+      arma::vec new_x, new_z;
+      new_x.zeros(x.GetArray().Size());
+      new_z.zeros(z.GetArray().Size());
+
+      for (SizeType i = 0; i < this->getnVarinEPEC(); i++)
+        new_x.at(i) = x[i].GetDouble();
+
+      for (SizeType i = 0; i < this->getnVarinEPEC(); i++)
+        new_z.at(i) = z[i].GetDouble();
+      ifs.close();
+      this->warmstart(new_x, new_z);
+    } catch (exception &e) {
+      cerr << "Exception in Models::readSolutionJSON : cannot read instance "
+              "file."
+           << e.what() << '\n';
+      throw;
+    } catch (...) {
+      cerr
+          << "Exception in Models::readSolutionJSON: cannot read instance file."
+          << '\n';
+      throw;
+    }
+  } else {
+    cerr << "Exception in Models::readSolutionJSON : file instance not found."
+         << '\n';
+    throw;
+  }
+}
+
 void Models::EPEC::writeSolution(const int writeLevel, string filename) const {
   /**
    * @brief Writes the computed Nash Equilibrium in the EPEC instance

src/games.h

@@ -492,6 +492,9 @@ class EPEC {
   arma::vec sol_z, ///< Solution equation values
       sol_x;       ///< Solution variable values
 
+  bool warmstart(const arma::vec x,
+                 const arma::vec z); ///< Warmstarts EPEC with a solution
+
 private:
   virtual void add_Dummy_Lead(
       const unsigned int i) final; ///< Add Dummy variables for the leaders

src/models.h

@@ -276,6 +276,8 @@ class EPEC : public Game::EPEC {
 
   void write(const std::string filename, bool append = true) const;
 
+  void readSolutionJSON(const std::string filename);
+
   void gur_WriteCountry_conv(const unsigned int i, std::string filename) const;
 
   void gur_WriteEpecMip(const unsigned int i, std::string filename) const;