don't output tree

main.cpp

@@ -29,7 +29,7 @@ int main(int argc, char** argv) {
     unsigned N = sim.getNParticles();
     std::cout << "N = " << N << std::endl;
     
-    sim.saveTree2file("../out/tree.txt");
+    // sim.saveTree2file("../out/tree.txt");
 
     try {
         std::cout << "Running simulation..." << std::endl;
@@ -40,11 +40,12 @@ int main(int argc, char** argv) {
         auto duration = std::chrono::duration_cast<std::chrono::milliseconds>(stop - start);
         std::cout << "Computation Time: " << duration.count()/1000.0 << " seconds" << std::endl;
     } catch (std::exception& e) {
-        std::cerr << e.what() << std::endl;
         // save state of simulation
         std::ofstream errfile("../out/errstate.txt");
         sim.saveState2file(nSteps, errfile);
+        
         errfile.close();
+        std::cerr << e.what() << std::endl;
         return 1;
     }