Write progress to stderr

src/one-body-sample.cc

@@ -294,8 +294,8 @@ int main(int argc, char *argv[]) {
             }
           }
           if (parset.get<bool>("printProgress")) {
-            std::cout << '.';
-            std::cout.flush();
+            std::cerr << '.';
+            std::cerr.flush();
           }
           if (energyNorm.diff(u_diff_saved, u_diff) <
               parset.get<double>("solver.tnnmg.fixed_point_tolerance"))
@@ -306,7 +306,7 @@ int main(int argc, char *argv[]) {
                       << " iterations" << std::endl;
         }
         if (parset.get<bool>("printProgress"))
-          std::cout << std::endl;
+          std::cerr << std::endl;
 
         // Record the state, (scaled) displacement, and Neumann
         // condition at a fixed node