Provide a nicer initial iterate; on S_F as well

src/one-body-sample.cc

@@ -356,10 +356,24 @@ int main(int argc, char *argv[]) {
         // Choose an initial iterate that is admissable
         // and non-zero in as many places as possible
         if (run == 1)
-          for (size_t i = 0; i < ignoreNodes.size(); ++i)
-            if (!ignoreNodes[i][1]) // Leave out partial DOF-restrictions as
-                                    // well
-              u4_diff[i] = 1;
+          for (size_t i = 0; i < ignoreNodes.size(); ++i) {
+            size_t const count = ignoreNodes[i].count();
+
+            if (count == dim)
+              continue;
+
+            if (count == 0) {
+              u4_diff[i] = 1e-4;
+              continue;
+            }
+
+            assert(count == 1);
+            assert(ignoreNodes[i][1]); // Only the y coordinate is allowed to be
+                                       // fixed
+            for (int j = 0; j < dim; ++j)
+              if (j != 1)
+                u4_diff[i][j] = 1e-4;
+          }
 
         MyBlockProblemType myBlockProblem(parset, myConvexProblem);
         multigridStep->setProblem(u4_diff, myBlockProblem);