Some fixes

src/core/diffusion/euler_grid.cc

@@ -39,10 +39,6 @@ void EulerGrid::DiffuseWithClosedEdge(double dt) {
 #pragma omp simd
         for (x = 1; x < nx - 1; x++) {
           ++c;
-          ++n;
-          ++s;
-          ++b;
-          ++t;
 
           if (y == 0 || y == (ny - 1) || z == 0 || z == (nz - 1)) {
             continue;
@@ -58,11 +54,6 @@ void EulerGrid::DiffuseWithClosedEdge(double dt) {
                d * dt * (c1_[b] - 2 * c1_[c] + c1_[t]) * ibl2) *
               (1 - mu_);
         }
-        ++c;
-        ++n;
-        ++s;
-        ++b;
-        ++t;
       }  // tile ny
     }    // tile nz
   }      // block ny

src/core/diffusion/runge_kutta_grid.cc

@@ -42,10 +42,6 @@ void RungeKuttaGrid::DiffuseWithClosedEdge(double dt) {
 #pragma omp simd
             for (x = 1; x < nx - 1; x++) {
               ++c;
-              ++n;
-              ++s;
-              ++b;
-              ++t;
 
               if (y == 0 || y == (ny - 1) || z == 0 || z == (nz - 1)) {
                 continue;
@@ -71,11 +67,6 @@ void RungeKuttaGrid::DiffuseWithClosedEdge(double dt) {
                 c2_[c] = c1_[c] + (k_[1] * h);
               }
             }
-            ++c;
-            ++n;
-            ++s;
-            ++b;
-            ++t;
           }  // tile ny
         }    // tile nz
       }      // block ny

src/core/resource_manager.cc

@@ -201,7 +201,6 @@ void ResourceManager::ForEachAgentParallel(
 struct LoadBalanceFunctor : public Functor<void, Iterator<AgentHandle>*> {
   bool minimize_memory;
   uint64_t offset;
-  uint64_t offset_in_numa;
   uint64_t nid;
   std::vector<std::vector<Agent*>>& agents;
   std::vector<Agent*>& dest;

src/core/util/random.cc

@@ -147,9 +147,6 @@ template MathArray<int, 2> DistributionRng<int>::Sample2();
 // -----------------------------------------------------------------------------
 template <typename TSample>
 MathArray<TSample, 2> DistributionRng<TSample>::Sample2Impl(TRandom* rng) {
-  MathArray<TSample, 2> ret;
-  ret[0] = Sample();
-  ret[0] = Sample();
   return MathArray<TSample, 2>({Sample(), Sample()});
 }
 template MathArray<double, 2> DistributionRng<double>::Sample2Impl(TRandom*);

src/core/visualization/paraview/vtk_diffusion_grid.cc

@@ -24,6 +24,7 @@
 // BioDynaMo
 #include "core/param/param.h"
 #include "core/simulation.h"
+#include "core/util/log.h"
 #include "core/util/thread_info.h"
 #include "core/visualization/paraview/parallel_vti_writer.h"
 
@@ -55,27 +56,33 @@ VtkDiffusionGrid::VtkDiffusionGrid(const std::string& name,
     }
   }
 
-  for (uint64_t i = 0; i < data_.size(); ++i) {
-    // Add attribute data
-    if (vd->concentration) {
-      vtkNew<vtkDoubleArray> concentration;
-      concentration->SetName("Substance Concentration");
-      concentration_array_idx_ =
-          data_[i]->GetPointData()->AddArray(concentration.GetPointer());
-    }
-    if (vd->gradient) {
-      vtkNew<vtkDoubleArray> gradient;
-      gradient->SetName("Diffusion Gradient");
-      gradient->SetNumberOfComponents(3);
-      gradient_array_idx_ =
-          data_[i]->GetPointData()->AddArray(gradient.GetPointer());
+  // If statement to prevent possible dereferencing of nullptr
+  if (vd) {
+    for (uint64_t i = 0; i < data_.size(); ++i) {
+      // Add attribute data
+      if (vd->concentration) {
+        vtkNew<vtkDoubleArray> concentration;
+        concentration->SetName("Substance Concentration");
+        concentration_array_idx_ =
+            data_[i]->GetPointData()->AddArray(concentration.GetPointer());
+      }
+      if (vd->gradient) {
+        vtkNew<vtkDoubleArray> gradient;
+        gradient->SetName("Diffusion Gradient");
+        gradient->SetNumberOfComponents(3);
+        gradient_array_idx_ =
+            data_[i]->GetPointData()->AddArray(gradient.GetPointer());
+      }
     }
-  }
 
-  if (!param->export_visualization) {
-    data_description->AddInput(name.c_str());
-    data_description->GetInputDescriptionByName(name.c_str())
-        ->SetGrid(data_[0]);
+    if (!param->export_visualization) {
+      data_description->AddInput(name.c_str());
+      data_description->GetInputDescriptionByName(name.c_str())
+          ->SetGrid(data_[0]);
+    }
+  } else {
+    Log::Warning("VtkDiffusionGrid::VtkDiffusionGrid", "Variable `name` (",
+                 name, ") not found in `param->visualize_diffusion`.");
   }
 }