From 9ca03c96f683ff9f4e6ed48a7b070efabb549285 Mon Sep 17 00:00:00 2001
From: guido <guido@0785d39b-7218-0410-832d-ea1e28bc413d>
Date: Thu, 7 Dec 2000 17:39:45 +0000
Subject: [PATCH] new function Q1Wedge

git-svn-id: https://svn.dealii.org/trunk@3529 0785d39b-7218-0410-832d-ea1e28bc413d
---
 deal.II/base/include/base/function_lib.h | 52 ++++++++++++++
 deal.II/base/source/function_lib.cc      | 87 ++++++++++++++++++++++++
 2 files changed, 139 insertions(+)

diff --git a/deal.II/base/include/base/function_lib.h b/deal.II/base/include/base/function_lib.h
index 19f43e7ab0..cf57ccac3c 100644
--- a/deal.II/base/include/base/function_lib.h
+++ b/deal.II/base/include/base/function_lib.h
@@ -73,6 +73,58 @@ class SquareFunction : public Function<dim>
 
 
 
+/**
+ * The function @p{xy}. This function serves as an example for
+ * a vanishing Laplacian.
+ *
+ * @author: Guido Kanschat, 2000
+ */
+template<int dim>
+class Q1WedgeFunction : public Function<dim>
+{
+  public:
+				     /**
+				      * Function value at one point.
+				      */
+    virtual double value (const Point<dim>   &p,
+			  const unsigned int  component = 0) const;
+
+				     /**
+				      * Function values at multiple points.
+				      */
+    virtual void value_list (const vector<Point<dim> > &points,
+			     vector<double>            &values,
+			     const unsigned int         component = 0) const;
+
+				     /**
+				      * Gradient at one point.
+				      */
+    virtual Tensor<1,dim> gradient (const Point<dim>   &p,
+				    const unsigned int  component = 0) const;
+
+				     /**
+					Gradients at multiple points.
+				      */
+    virtual void gradient_list (const vector<Point<dim> > &points,
+				vector<Tensor<1,dim> >    &gradients,
+				const unsigned int         component = 0) const;
+
+				     /**
+				      * Laplacian of the function at one point.
+				      */
+    virtual double laplacian (const Point<dim>   &p,
+			      const unsigned int  component = 0) const;
+
+				     /**
+				      * Laplacian of the function at multiple points.
+				      */
+    virtual void laplacian_list (const vector<Point<dim> > &points,
+				 vector<double>            &values,
+				 const unsigned int         component = 0) const;
+};
+
+
+
 /**
  * d-quadratic pillow on the unit hypercube.
  *
diff --git a/deal.II/base/source/function_lib.cc b/deal.II/base/source/function_lib.cc
index 66df13b319..2a7a63ca76 100644
--- a/deal.II/base/source/function_lib.cc
+++ b/deal.II/base/source/function_lib.cc
@@ -108,6 +108,90 @@ SquareFunction<dim>::gradient_list (const vector<Point<dim> > &points,
 //////////////////////////////////////////////////////////////////////
 
 
+template<int dim>
+double
+Q1WedgeFunction<dim>::value (const Point<dim>   &p,
+			    const unsigned int) const
+{
+  return p(0)*p(1);
+}
+
+
+
+template<int dim>
+void
+Q1WedgeFunction<dim>::value_list (const vector<Point<dim> > &points,
+				 vector<double>            &values,
+				 const unsigned int) const
+{
+  Assert (values.size() == points.size(),
+	  ExcDimensionMismatch(values.size(), points.size()));
+
+  for (unsigned int i=0;i<points.size();++i)
+    {
+      const Point<dim>& p = points[i];
+      values[i] = p(0)*p(1);
+    }
+}
+
+
+template<int dim>
+double
+Q1WedgeFunction<dim>::laplacian (const Point<dim>   &,
+				const unsigned int) const
+{
+  return 0.;
+}
+
+
+template<int dim>
+void
+Q1WedgeFunction<dim>::laplacian_list (const vector<Point<dim> > &points,
+				     vector<double>            &values,
+				     const unsigned int) const
+{
+  Assert (values.size() == points.size(),
+	  ExcDimensionMismatch(values.size(), points.size()));
+
+  for (unsigned int i=0;i<points.size();++i)
+    values[i] = 0.;
+}
+
+
+
+template<int dim>
+Tensor<1,dim>
+Q1WedgeFunction<dim>::gradient (const Point<dim>   &p,
+			       const unsigned int) const
+{
+  Tensor<1,dim> erg;
+  erg[0] = p(1);
+  erg[1] = p(0);
+  return erg;
+}
+
+
+
+template<int dim>
+void
+Q1WedgeFunction<dim>::gradient_list (const vector<Point<dim> > &points,
+				    vector<Tensor<1,dim> >    &gradients,
+				    const unsigned int) const
+{
+  Assert (gradients.size() == points.size(),
+	  ExcDimensionMismatch(gradients.size(), points.size()));
+
+  for (unsigned int i=0; i<points.size(); ++i)
+    {
+      gradients[i][0] = points[i](1);
+      gradients[i][1] = points[i](0);
+    }
+}
+
+
+//////////////////////////////////////////////////////////////////////
+
+
 template<int dim>
 PillowFunction<dim>::PillowFunction (const double offset)
 		:
@@ -902,6 +986,9 @@ JumpFunction<dim>::memory_consumption () const
 template SquareFunction<1>;
 template SquareFunction<2>;
 template SquareFunction<3>;
+template Q1WedgeFunction<1>;
+template Q1WedgeFunction<2>;
+template Q1WedgeFunction<3>;
 template PillowFunction<1>;
 template PillowFunction<2>;
 template PillowFunction<3>;
-- 
2.39.5