From 9ea062b0d4120306e12a400ccabba31deb2eb565 Mon Sep 17 00:00:00 2001
From: Oliver Sander <sander@igpm.rwth-aachen.de>
Date: Thu, 18 Feb 2010 17:17:06 +0000
Subject: [PATCH] implement fd approximation of the gradient for
unit-vector-valued functions
[[Imported from SVN: r5590]]
---
src/localgeodesicfestiffness.hh | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/src/localgeodesicfestiffness.hh b/src/localgeodesicfestiffness.hh
index b1862fa3..e2b16b7d 100644
--- a/src/localgeodesicfestiffness.hh
+++ b/src/localgeodesicfestiffness.hh
@@ -304,7 +304,7 @@ class LocalGeodesicFEStiffness <GridView,UnitVector<dim> >
/** \brief For the fd approximations
*/
- static Dune::FieldVector<double,dim> infinitesimalVariation(UnitVector<dim>& c, double eps, int i)
+ static Dune::FieldVector<double,dim> infinitesimalVariation(const UnitVector<dim>& c, double eps, int i)
{
Dune::FieldVector<double,dim> result = c.globalCoordinates();
result[i] += eps;
@@ -386,12 +386,13 @@ assembleGradient(const Entity& element,
for (int j=0; j<blocksize; j++) {
- infinitesimalVariation(forwardSolution[i], eps, j);
- infinitesimalVariation(backwardSolution[i], -eps, j);
-
+ // Brute force: the return value does not have unit norm. Stuff it in there anyways
+ forwardSolution[i].data_ = infinitesimalVariation(localSolution[i], eps, j);
+ backwardSolution[i].data_ = infinitesimalVariation(localSolution[i], -eps, j);
+
localGradient[i][j] = (energy(element,forwardSolution) - energy(element,backwardSolution))
/ (2*eps);
-
+
forwardSolution[i] = localSolution[i];
backwardSolution[i] = localSolution[i];
}
--
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