hp.cc modifications

src/solvers/hp/hp.cc

@@ -34,29 +34,33 @@ HPStrategySolve(const MixedStrategyProfile<double> &p_prior)
   std::list<MixedStrategyProfile<double>> equilibria;
 
   HPEquationSystem system(p_prior);
-  Vector<double> x = system.ComputeInitialPoint();
 
   const PathTracer tracer;
-  double omega = 1.0;
+  Vector<double> x;
+  double p_omega = 1.0;
 
-  auto termination_condition = [](const Vector<double> &point) { return point[1] >= 1.5; };
-  auto criterion_function = [](const Vector<double> &point,
-                               const Vector<double> &tangent) -> double { return point[1] - 1.0; };
+  const double t_target = 1.0;
+  const double t_tol = 0.5;
+
+  auto criterion_function = [t_target](const Vector<double> &point,
+                                       const Vector<double> &tangent) -> double {
+    return point[1] - t_target;
+  };
+
+  x = system.ComputeInitialPoint();
+
+  auto termination_condition = [t_target, t_tol](const Vector<double> &point) {
+    return (point[1] >= t_target + t_tol);
+  };
 
   const TracePathResult result = tracer.TracePath(
       [&system](const Vector<double> &point, Vector<double> &lhs) { system.GetValue(point, lhs); },
       [&system](const Vector<double> &point, Matrix<double> &jac) {
         system.GetJacobian(point, jac);
       },
-      x, omega, termination_condition,
+      x, p_omega, termination_condition,
       [&system](const Vector<double> &point) {
-        std::cout << "[Path Tracer Step] t = " << point[1];
-        std::cout << " | Alfas: ";
-        for (size_t i = 2; i <= 5; ++i) {
-          std::cout << point[i] << " ";
-        }
-        std::cout << "| Mu: " << point[6] << " " << point[7] << std::endl;
-
+        std::cout << "[Path Tracer Step] t = " << point[1] << std::endl;
         std::cout << "Full point vector in probabilities: ";
         Vector<double> prob_vector = system.ExtractEquilibrium(point).GetProbVector();
         for (size_t i = 1; i <= prob_vector.size(); ++i) {
@@ -66,7 +70,23 @@ HPStrategySolve(const MixedStrategyProfile<double> &p_prior)
       },
       criterion_function);
 
-  equilibria.push_back(system.ExtractEquilibrium(x));
+  const MixedStrategyProfile<double> eq_profile = system.ExtractEquilibrium(x);
+
+  equilibria.push_back(eq_profile);
+
+  // Check that the profile is an equilibrium taking into account how far we are from the target t
+  // value
+  const double delta = std::abs(t_target - x[1]);
+  const double scale = p_prior.GetGame()->GetMaxPayoff() - p_prior.GetGame()->GetMinPayoff();
+  const double max_regret = eq_profile.GetMaxRegret();
+  // error tolerance <= delta * scale
+  const double error_tolerance =
+      (delta * scale) + 1e-6; // Add a small epsilon to account for numerical errors
+
+  // If it is not an equilibrium, return an empty list
+  if (max_regret > error_tolerance) {
+    return {};
+  }
   return equilibria;
 }
 } // namespace Gambit