-------- Original Message --------
Subject: TPS 3D negative bending energy
Date: Wed, 2 Feb 2011 16:00:57 -0500
From: Stefan Schlager <[email protected]>
To: [email protected]
Dear morphometricans,
I'm currently programming on calculations of principal and relative
warps in R ( programming the functions helps me grasping the maths
behind). Everything works great in 2D - I'm getting the exact same
results as Bookstein (although the erroneous coefficients in the paper
of 1989 stole me a day) and Dryden in their papers/books. Now in the 3D
case I observed negative eigenvalues of the bending energy matrix -
getting energy from bending doesn't make sense. I happened to see that
Dryden uses the negative 3d kernel function (U(r)=-|r| instead of
U(r)=|r|) to calculate the bending energy matrix . For me, all other
applications however work perfect with the "normal" kernel. Are there
any papers out there on this problem/solution, dealing with the maths?
Thanks
Stefan
--
Stefan Schlager M.A.
Anthropologie
Medizinische Fakultät der der Albert Ludwigs- Universität Freiburg
Hebelstr. 29
79104 Freiburg
Anthropology
Faculty of Medicine, Albert-Ludwigs-University Freiburg
Hebelstr. 29
D- 79104 Freiburg
phone +49 (0)761 203-5522
fax +49 (0)761 203-6898
