Fix step-77: zero out residual before assembly

dealii · May 13, 2023 · ce7b7b6 · ce7b7b6
1 parent 89a79f2
commit ce7b7b6
Show file tree

Hide file tree

Showing 2 changed files with 4 additions and 0 deletions.
diff --git a/examples/step-77/step-77.cc b/examples/step-77/step-77.cc
@@ -334,6 +334,8 @@ namespace Step77
 
     std::cout << "  Computing residual vector..." << std::flush;
 
+    residual = 0.0;
+
     const QGauss<dim> quadrature_formula(fe.degree + 1);
     FEValues<dim>     fe_values(fe,
                             quadrature_formula,

diff --git a/tests/sundials/step-77.cc b/tests/sundials/step-77.cc
@@ -243,6 +243,8 @@ namespace Step77
     const Vector<double> &evaluation_point,
     Vector<double> &      residual)
   {
+    residual = 0.0;
+
     const QGauss<dim> quadrature_formula(fe.degree + 1);
     FEValues<dim>     fe_values(fe,
                             quadrature_formula,