From fc9951e76d0faf324740c00127a42f421bc45289 Mon Sep 17 00:00:00 2001
From: Jesse Carter <jesse.carter@gmail.com>
Date: Tue, 26 Jul 2016 22:53:23 -0400
Subject: [PATCH] made MaterialDiffusion kernel simpler

---
 include/kernels/MaterialDiffusion.h | 23 +++++++++-------
 src/kernels/MaterialDiffusion.C     | 41 ++++++++++++++++-------------
 2 files changed, 37 insertions(+), 27 deletions(-)

diff --git a/include/kernels/MaterialDiffusion.h b/include/kernels/MaterialDiffusion.h
index e24af3f422..20fc4474de 100644
--- a/include/kernels/MaterialDiffusion.h
+++ b/include/kernels/MaterialDiffusion.h
@@ -11,31 +11,36 @@
 /*                                                              */
 /*            See COPYRIGHT for full restrictions               */
 /****************************************************************/
+
 #ifndef MATERIALDIFFUSION_H
 #define MATERIALDIFFUSION_H
 
-#include "Kernel.h"
-#include "MaterialProperty.h"
+#include "Diffusion.h"
 
-// Forward Declaration
+//Forward Declarations
 class MaterialDiffusion;
 
+/**
+ * validParams returns the parameters that this Kernel accepts / needs
+ * The actual body of the function MUST be in the .C file.
+ */
 template<>
 InputParameters validParams<MaterialDiffusion>();
 
-
-class MaterialDiffusion : public Kernel
+class MaterialDiffusion : public Diffusion
 {
 public:
+
   MaterialDiffusion(const InputParameters & parameters);
 
 protected:
   virtual Real computeQpResidual();
-
   virtual Real computeQpJacobian();
 
-  std::string _prop_name;
-  const MaterialProperty<Real> * _diff;
+  /**
+   * This MooseArray will hold the reference we need to our
+   * material property from the Material class
+   */
+  const MaterialProperty<Real> & _diffusivity;
 };
-
 #endif //MATERIALDIFFUSION_H
diff --git a/src/kernels/MaterialDiffusion.C b/src/kernels/MaterialDiffusion.C
index f6c5ecdfbd..b1c697ff5b 100644
--- a/src/kernels/MaterialDiffusion.C
+++ b/src/kernels/MaterialDiffusion.C
@@ -11,41 +11,46 @@
 /*                                                              */
 /*            See COPYRIGHT for full restrictions               */
 /****************************************************************/
+
 #include "MaterialDiffusion.h"
 
+/**
+ * This function defines the valid parameters for
+ * this Kernel and their default values
+ */
 template<>
 InputParameters validParams<MaterialDiffusion>()
 {
-  InputParameters params = validParams<Kernel>();
-  params.addRequiredParam<MaterialPropertyName>("prop_name", "the name of the material property we are going to use");
-
-  MooseEnum prop_state("current old older", "current");
-  params.addParam<MooseEnum>("prop_state", prop_state, "Declares which property state we should retrieve");
+  InputParameters params = validParams<Diffusion>();
   return params;
 }
 
 
 MaterialDiffusion::MaterialDiffusion(const InputParameters & parameters) :
-    Kernel(parameters)
-{
-  MooseEnum prop_state = getParam<MooseEnum>("prop_state");
-
-  if (prop_state == "current")
-    _diff = &getMaterialProperty<Real>("prop_name");
-  else if (prop_state == "old")
-    _diff = &getMaterialPropertyOld<Real>("prop_name");
-  else if (prop_state == "older")
-    _diff = &getMaterialPropertyOlder<Real>("prop_name");
-}
+    Diffusion(parameters),
+    _diffusivity(getMaterialProperty<Real>("diffusivity"))
+{}
 
 Real
 MaterialDiffusion::computeQpResidual()
 {
-  return (*_diff)[_qp] * _grad_test[_i][_qp] * _grad_u[_qp];
+  // We're dereferencing the _diffusivity pointer to get to the
+  // material properties vector... which gives us one property
+  // value per quadrature point.
+
+  // Also... we're reusing the Diffusion Kernel's residual
+  // so that we don't have to recode that.
+  return _diffusivity[_qp]*Diffusion::computeQpResidual();
 }
 
 Real
 MaterialDiffusion::computeQpJacobian()
 {
-  return (*_diff)[_qp] * _grad_test[_i][_qp] * _grad_phi[_j][_qp];
+  // We're dereferencing the _diffusivity pointer to get to the
+  // material properties vector... which gives us one property
+  // value per quadrature point.
+
+  // Also... we're reusing the Diffusion Kernel's residual
+  // so that we don't have to recode that.
+  return _diffusivity[_qp]*Diffusion::computeQpJacobian();
 }