|
Please disregard any emails about an invitation to Bebo sorry tricked by spam. |
morphmet <[EMAIL PROTECTED]> wrote:Once the semilandmarks have been slid as part of the GPA, they are then
treated as ordinary landmarks - except that one will find that each
semilandmark essentially adds just one rather than two dimensions to the
shape space. This is not a problem in a PCA but requires some extra care in
a CVA.
--------------------
F. James Rohlf, Distinguished Professor, Graduate Program Director
Dept. Ecology & Evolution, Stony Brook University, Stony Brook, NY
11794-5345
Web: http://life.bio.sunysb.edu/ee/rohlf
Morphometrics: http://life.bio.sunysb.edu/morph
> -----Original Message-----
> From: morphmet [mailto:[EMAIL PROTECTED]
> Sent: Thursday, May 26, 2005 10:26 AM
> To: morphmet
> Subject: RE: Morphometric analysis
>
> Hi,
> I have a question about the analysis of semi-landmarks.
> Which is typically analysed after the thin-plate spline plus
> registration routine?
> A) The final coordinates of the semi-landmarks
> analysed as if they started as regular landmarks, or
> B) The distances, normal to the outlines, between the
> final semi-landmarks and the outlines.
> Best regards,
> Ben
> p.s. Have both been used?
>
> -----Original Message-----
> From: morphmet [mailto:[EMAIL PROTECTED]
> Sent: 26 May 2005 14:26
> To: morphmet
> Subject: Re: Morphometric analysis
>
>
> Dear Catherine,
>
> You should use the PW scores matrix in all subsequent
> analyses of GM data using multivariate methods.
>
> By the way, your mollusk shells would provide an interesting
> application for
>
> the still little explored "semilandmark" approach developed
> by Fred Bookstein (and implemented by Jim Rohlf in the
> TPSRelw program).
>
> Hope this helps.
>
> With best regards,
>
> On Thu, 26 May 2005 08:06:56 -0400, morphmet wrote
>
> > I'm a first year Ph.D student in the Ecology and Evolution
> Department
> > at Leeds University, England. I'm studying a cline in
> morphotype in
> > the inter tidal snail Littorina saxatilis which suggests
> there may be
> > speciation in progress. I am very interested in using geometric
> > morphometrics to quantify the variation in shell shape of
> the snails,
> > although my knowledge of the field is limited at this stage.
> >
> > I have taken the route of landmarks and I am using the
> software TPS.
> > I plan to use PCA/DFA in an attempt to discriminate between the
> > morphotypes. However, I am unsure whether to use! the Partial warp
> > scores matrix, Relative warps score matrix or Weight matrix
> from the
> > TPSRelw program in the analysis.
> >
> > I would be grateful for any advice.
> >
> > Catherine Sinfield
>
> --
> + - - - - - - - - - - - - Mauro J. Cavalcanti - - - - - - - -
> - - - - +
> | Programa de P�s-Gradua��o em Zoologia
> |
> | Museu Nacional/Universidade Federal do Rio de
> Janeiro |
> | Quinta da Boa Vista, 20940-040, Rio de Janeiro, RJ,
> BRASIL |
> | E-mail: [EMAIL PROTECTED]
> |
> | Web: http://maurobio.infobio.net
> |
> + - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
> - - - - +
> --
> Replies will be sent to the list.
> For more information visit http://www.morphometrics.org
>
--
Replies will be sent to the list.
For more information visit http://www.morphometrics.org
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
