Add tests for local/global subdiff gap

src/test-gradient-method.cc

@@ -358,6 +358,84 @@ void testSampleFunction2() {
   assert(std::abs(ret1 - ret3) < 1e-5);
 }
 
+void testSampleFunctionSteep1() {
+  int const dim = 2;
+  typedef Dune::SampleFunctional<dim> Functional;
+
+  Functional::SmallMatrix A;
+  A[0][0] = 1;
+  A[0][1] = 0;
+  A[1][0] = 0;
+  A[1][1] = 1;
+  Functional::SmallVector b;
+  b[0] = 1;
+  b[1] = 2;
+
+  Dune::SampleFunction f;
+  Functional J(A, b, Dune::MyNonlinearity<dim>(f));
+
+  Functional::SmallVector start;
+
+  start[0] = 0;
+  start[1] = 1;
+
+  double const ret1 = functionTester(J, start, 7);
+
+  // Something random
+  start[0] = 279;
+  start[1] = -96;
+
+  double const ret2 = functionTester(J, start, 7);
+  assert(std::abs(ret1 - ret2) < 1e-5);
+
+  start[0] = 0;
+  start[1] = 0;
+
+  double const ret3 = functionTester(J, start, 2);
+  assert(std::abs(ret1 - ret3) < 1e-5);
+}
+
+void testSampleFunctionSteep2() {
+  int const dim = 2;
+  typedef Dune::SampleFunctional<dim> Functional;
+
+  Functional::SmallMatrix A;
+  A[0][0] = 1;
+  A[0][1] = 0;
+  A[1][0] = 0;
+  A[1][1] = 1;
+  Functional::SmallVector b;
+  b[0] = 1;
+  b[1] = 2.5;
+
+  Dune::SampleFunction f;
+  Functional J(A, b, Dune::MyNonlinearity<dim>(f));
+
+  Functional::SmallVector start;
+
+  start[0] = 0;
+  start[1] = 1;
+
+  double const ret1 = functionTester(J, start, 7);
+
+  // Something random
+  start[0] = 279;
+  start[1] = -96;
+
+  double const ret2 = functionTester(J, start, 7);
+  assert(std::abs(ret1 - ret2) < 1e-5);
+
+  start[0] = 0;
+  start[1] = 0;
+
+  start[0] = 0.4;
+  start[1] = 1.0;
+  start /= start.two_norm();
+
+  double const ret3 = functionTester(J, start, 3);
+  assert(std::abs(ret1 - ret3) < 1e-5);
+}
+
 int main() {
   try {
     testIdentity();
@@ -375,6 +453,10 @@ int main() {
     testSampleFunction2();
     std::cout << std::endl << std::endl << std::endl;
     testSampleFunction3D();
+    std::cout << std::endl << std::endl << std::endl;
+    testSampleFunctionSteep1();
+    std::cout << std::endl << std::endl << std::endl;
+    testSampleFunctionSteep2();
     return 0;
   }
   catch (Dune::Exception &e) {