]> https://gitweb.dealii.org/ - dealii-svn.git/commitdiff
Add comment on ordering of shape functions and definition of eta and zeta.
authorhartmann <hartmann@0785d39b-7218-0410-832d-ea1e28bc413d>
Wed, 29 Jun 2005 15:51:35 +0000 (15:51 +0000)
committerhartmann <hartmann@0785d39b-7218-0410-832d-ea1e28bc413d>
Wed, 29 Jun 2005 15:51:35 +0000 (15:51 +0000)
git-svn-id: https://svn.dealii.org/trunk@10972 0785d39b-7218-0410-832d-ea1e28bc413d

deal.II/deal.II/source/grid/tria_accessor.cc

index 40bf7421e775f605cc691265875c710070bb4c31..48df4c7b74d7bd66e2198f7ff3417520d07fd714 100644 (file)
@@ -906,6 +906,13 @@ Point<3> TriaObjectAccessor<3, 3>::barycenter () const
   \vec x_s = 1/|K| \int_K \vec x dx dy dz
   = 1/|K| \int_{\hat K} \vec x(xi,eta,zeta) |det J| d(xi) d(eta) d(zeta)
 
+  Note, that in the ordering of the shape functions tphi[0]-tphi[7]
+  below, eta and zeta have been exchanged (zeta belongs to the y, and
+  eta to the z direction). However, the resulting Jacobian determinant
+  detJ should be the same, as a matrix and the matrix created from it
+  by exchanging two consecutive lines and two neighboring columns have
+  the same determinant.
+  
   # x, y and z are arrays holding the x-, y- and z-values of the four vertices
   # of this cell in real space. 
   x := array(0..7):

In the beginning the Universe was created. This has made a lot of people very angry and has been widely regarded as a bad move.

Douglas Adams


Typeset in Trocchi and Trocchi Bold Sans Serif.