1 files changed, 20 insertions, 9 deletions
diff --git a/langevin.cpp b/langevin.cpp
index f494809..cf61b85 100644
--- a/langevin.cpp
+++ b/langevin.cpp
@@ -26,6 +26,12 @@ Vector randomVector(unsigned N, Distribution d, Generator& r) {
   return z;
 }
 
+class gradientDescentStallException: public std::exception {
+  virtual const char* what() const throw() {
+    return "Gradient descent stalled.";
+  }
+} gradientDescentStall;
+
 std::tuple<double, Vector> gradientDescent(const Tensor& J, const Vector& z0, double ε, double γ0 = 1, double δγ = 2) {
   Vector z = z0;
   double γ = γ0;
@@ -46,9 +52,8 @@ std::tuple<double, Vector> gradientDescent(const Tensor& J, const Vector& z0, do
       γ /= δγ;
     }
 
-    if (γ < 1e-15) {
-      std::cerr << "Gradient descent stalled." << std::endl;
-      exit(1);
+    if (γ < 1e-50) {
+      throw gradientDescentStall;
     }
   }
 
@@ -182,13 +187,19 @@ int main(int argc, char* argv[]) {
   Vector z = zSaddle;
   for (unsigned i = 0; i < n; i++) {
     std::tie(W, z) = langevin(J, z, T, γ, M, r);
-    Vector zNewSaddle = findSaddle(J, z, ε);
-    Scalar H;
-    Matrix ddH;
-    std::tie(H, std::ignore, ddH) = hamGradHess(J, zNewSaddle);
-    Eigen::SelfAdjointEigenSolver<Matrix> es(ddH.adjoint() * ddH);
-    std::cout << (zNewSaddle - zSaddle).norm() << " " << real(H) << " " << imag(H) << " " << es.eigenvalues().transpose() << std::endl;
+    try {
+      Vector zNewSaddle = findSaddle(J, z, ε);
+      Scalar H;
+      Matrix ddH;
+      std::tie(H, std::ignore, ddH) = hamGradHess(J, zNewSaddle);
+      Eigen::SelfAdjointEigenSolver<Matrix> es(ddH.adjoint() * ddH);
+      std::cout << N << "\t" << M * (i+1) << "\t" << H << "\t"
+        << zNewSaddle.transpose() << "\t" << es.eigenvalues().transpose()
+        << std::endl;
     std::cerr << M * (i+1) << " steps taken to move " << (zNewSaddle - zSaddle).norm() << ", saddle information saved." << std::endl;
+    } catch (std::exception& e) {
+      std::cerr << "Could not find a saddle: " << e.what() << std::endl;
+    }
   }
 
   return 0;