-------- Original Message --------
Subject: RE: TPS 3D negative bending energy
Date: Mon, 7 Feb 2011 23:07:33 -0500
From: F. James Rohlf <ro...@life.bio.sunysb.edu>
Reply-To: ro...@life.bio.sunysb.edu
Organization: Stony Brook University
To: morphmet@morphometrics.org
It is the same minus sign whether put inside (as in Bookstein (1991) or
placed outside (as in Gunz et al. (2005)) the expression for bending
energy. Neither publication gives a derivation. Perhaps Bookstein will
join this thread and supply one.
----------------------
F. James Rohlf, John S. Toll Professor
Dept. Ecology and Evolution, Stony Brook University, NY 11794-5245
Please consider the environment before printing this email
-----Original Message-----
From: morphmet [mailto:morphmet_modera...@morphometrics.org]
Sent: Monday, February 07, 2011 8:03 AM
To: morphmet
Subject: Re: TPS 3D negative bending energy
-------- Original Message --------
Subject: Re: TPS 3D negative bending energy
Date: Mon, 7 Feb 2011 05:56:43 -0500
From: Stefan Schlager <stefan.schla...@uniklinik-freiburg.de>
To: morphmet@morphometrics.org
but hen again, in the article /Gunz, P.; Mitteroecker, P. & Bookstein, F. 2005.
Semilandmarks in three dimensions. In: Slice, D. (Ed.), Modern
Morphometrics in Physical Anthropology/, where Booksteinis co-author,
U=|r| is used, and as in most papers.
But as said before, the only difference seems to be the "negative"
bending energy. In the article stated above the bending energy is
calculated: t(-H)(L^-1)H - instead of t(H)(L^-1)H as usually - in order to make
up for the negative semidefinite bending energy matrix.
BTW:/ "FYI Bookstein (1991) - the "orange book" gives -|r| "/ - if
the orange book is: /Bookstein F, 1991. Morphometric tools for landmark
data/ - I couldn't find it there
greetings
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
On 06/02/11 17:10, morphmet wrote:
>
>
> -------- Original Message --------
> Subject: Re: TPS 3D negative bending energy
> Date: Fri, 4 Feb 2011 21:13:03 -0500
> From: F. James Rohlf <ro...@life.bio.sunysb.edu>
> Reply-To: ro...@life.bio.sunysb.edu
> To: Morphmet <morphmet@morphometrics.org>
>
> FYI Bookstein (1991) - the "orange book" gives -|r|
> -------
> Sent remotely by F. James Rohlf,
> John S. Toll Professor
>
> -----Original Message-----
> From: morphmet <morphmet_modera...@morphometrics.org>
> Date: Fri, 04 Feb 2011 16:42:51
> To: morphmet<morphmet@morphometrics.org>
> Reply-To: morphmet@morphometrics.org
> Subject: Re: TPS 3D negative bending energy
>
>
>
> -------- Original Message --------
> Subject: Re: TPS 3D negative bending energy
> Date: Fri, 4 Feb 2011 15:25:49 -0500
> From: Stefan Schlager <stefan.schla...@uniklinik-freiburg.de>
> To: morphmet@morphometrics.org
>
>
>
> I found the kernel U=|r| in most computer journals - e.g. in /Claes et
> al., Statistically deformable face models for craniofacial
> reconstruction. Journal of Computing and Information Technology - CIT,
> 14(1):21–30, 2006.
> /
> But as it was working excellent (the non-affine part of the spline is
> t(w)*(r) instead of t(-w)*(-r) - with (w) being my "old" coefficients
> and (r) the vector of ri=||(x,y,z)-(xi,yi,zi)||) , I never questioned
> the choice of the kernel (who am to do such a thing as I am quite a
> novice to this field). Up to this week I never noticed a difference,
> as the result of the spline is exactly the same. I used TPS only for
> actual deformation of 3d-meshes.
>
> thanks for answering
> greetings stefan
>
