calculate average temperature in mug

mgrid_2/geom.cpp

@@ -496,6 +496,34 @@ void Mesh::Visualize_paraview(vector<double> const &v) const
     return;
 }
 
+double Mesh::AverageVectorFunction_perSubdomain(std::vector<double> &v, int target_sd) const
+{
+    assert(2==Ndims());
+    int const nnode = Nnodes();            // number of vertices in mesh
+    assert( nnode == static_cast<int>(v.size()) );
+
+    double cumulative_element_temp = 0.0;
+    int subdomain_element_counter = 0;
+    for (int e = 0; e < Nelems(); ++e)      // loop over all elements
+    {  
+        int sd = ElementSubdomains[e];      // get subdomain of element e
+        if (sd == target_sd)                // if is target subdomain then
+        {
+            subdomain_element_counter++;
+            int base = e * _nvert_e;        // get starting index of element in coordinate vector
+            double cumulative_node_temp = 0.0;
+            for (int k = 0; k < _nvert_e; ++k)      // loop over vertices of element
+            {
+                int node = _ia[base + k];               // global index of vertex
+                cumulative_node_temp += v[node]; // set function
+            }
+            cumulative_element_temp += cumulative_node_temp/_nvert_e;
+        }
+    }
+
+    return cumulative_element_temp/subdomain_element_counter;
+}
+
 
 
 vector<int> Mesh::Index_DirichletNodes() const