From 21177d6088392675831dd373b649b64d11a390e5 Mon Sep 17 00:00:00 2001
From: Oliver Sander <sander@igpm.rwth-aachen.de>
Date: Fri, 19 Sep 2014 18:40:30 +0000
Subject: [PATCH] Implement the derivative of the projection onto the set of
unit vectors
This is needed for projection-based finite elements.
The code in this patch has not been tested yet.
[[Imported from SVN: r9887]]
---
dune/gfe/unitvector.hh | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/dune/gfe/unitvector.hh b/dune/gfe/unitvector.hh
index 63ce6f72..87875bf6 100644
--- a/dune/gfe/unitvector.hh
+++ b/dune/gfe/unitvector.hh
@@ -374,6 +374,15 @@ public:
return result;
}
+ static Dune::FieldMatrix<T, N, N> derivativeOfProjection(const Dune::FieldVector<T,N>& p)
+ {
+ Dune::FieldMatrix<T,N,N> result;
+ for (int i=0; i<N; i++)
+ for (int j=0; j<N; j++)
+ result[i][j] = ( (i==j) - p[i]*p[j] / p.two_norm2() ) / p.two_norm();
+ return result;
+ }
+
/** \brief The global coordinates, if you really want them */
const CoordinateType& globalCoordinates() const {
return data_;
--
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