Fix minor example issues

examples/external-lib-interfacing/external-lib-interfacing.cpp

@@ -906,7 +906,7 @@ void AdvectionProblem<dim>::solve()
                      preconditioner);
     *******************************************************/
 
-    // Give the solution back to deall.ii
+    // Distribute the possible hanging nodes constraints
     hanging_node_constraints.distribute(solution);
 }
 

examples/poisson-solver/poisson-solver.cpp

@@ -132,10 +132,12 @@ int main(int argc, char* argv[])
     }
 
     // Get number of discretization points
-    const auto executor_string = argc >= 2 ? argv[1] : "reference";
     const unsigned int discretization_points =
         argc >= 3 ? std::atoi(argv[2]) : 100;
 
+    // Get the executor string
+    const auto executor_string = argc >= 2 ? argv[1] : "reference";
+
     // Figure out where to run the code
     std::map<std::string, std::function<std::shared_ptr<gko::Executor>()>>
         exec_map{
@@ -162,7 +164,8 @@ int main(int argc, char* argv[])
     // executor used by the application
     const auto app_exec = exec->get_master();
 
-    // problem:
+    // Set up the problem: define the exact solution, the right hand side and
+    // the Dirichlet boundary condition.
     auto correct_u = [](ValueType x) { return x * x * x; };
     auto f = [](ValueType x) { return ValueType(6) * x; };
     auto u0 = correct_u(0);

examples/simple-solver/simple-solver.cpp

@@ -67,6 +67,7 @@ int main(int argc, char* argv[])
     // Print the ginkgo version information.
     std::cout << gko::version_info::get() << std::endl;
 
+    // Print help on how to execute this example.
     if (argc == 2 && (std::string(argv[1]) == "--help")) {
         std::cerr << "Usage: " << argv[0] << " [executor] " << std::endl;
         std::exit(-1);
@@ -114,7 +115,7 @@ int main(int argc, char* argv[])
     // the hood call the required smart pointer functions to manage object
     // ownership. The gko::share , gko::give and gko::lend are the functions
     // that you would need to use.
-    auto A = share(gko::read<mtx>(std::ifstream("data/A.mtx"), exec));
+    auto A = gko::share(gko::read<mtx>(std::ifstream("data/A.mtx"), exec));
     auto b = gko::read<vec>(std::ifstream("data/b.mtx"), exec);
     auto x = gko::read<vec>(std::ifstream("data/x0.mtx"), exec);