b is initialised by the functionalassembler

src/one-body-sample.cc

@@ -190,8 +190,8 @@ int main() {
     VectorType u2 = u1;
     CellVectorType vonMisesStress;
 
-    VectorType b1(grid.size(grid.maxLevel(), dim));
-    VectorType b2(grid.size(grid.maxLevel(), dim));
+    VectorType b1;
+    VectorType b2;
 
     std::vector<Dune::FieldVector<double, 1>> nodalIntegrals;
     assemble_frictional<GridType, GridType::LeafGridView, SmallVector, P1Basis>(