----- Forwarded message from morphmet_modera...@morphometrics.org -----
Date: Sun, 30 Mar 2014 22:05:51 -0700
From: morphmet_modera...@morphometrics.org
Reply-To: morphmet_modera...@morphometrics.org
Subject: Re: Question about DFA in MorphoJ
To: morphmet@morphometrics.org
----- Forwarded message from andrea cardini <alcard...@gmail.com> -----
Date: Tue, 18 Mar 2014 07:54:10 -0400
From: andrea cardini <alcard...@gmail.com>
Reply-To: andrea cardini <alcard...@gmail.com>
Subject: Re: Question about DFA in MorphoJ
To: morphmet@morphometrics.org, morphmet@morphometrics.org
Dear Dave,
please, read my answers below.
At 05:46 18/03/2014, morphmet_modera...@morphometrics.org wrote:
>----- Forwarded message from David Thulman <dthul...@gmail.com> -----
>
>Date: Wed, 5 Mar 2014 15:03:07 -0500
>From: David Thulman <dthul...@gmail.com>
>Reply-To: David Thulman <dthul...@gmail.com>
>Subject: Question about DFA in MorphoJ
>To: morphmet@morphometrics.org
>
>1. Is this possible to extract the Mahalanobis
>and Procrustes distances for each specimen in MorphoJ?
>
>2. If not, can someone suggest another program that can generate that data?
Not sure that you can do that in MorphoJ but you can:
a) get Procrustes distances from TPSSmall and
Morphologika for both 2D and 3D data (in Mlogika
they're in the csv result file that you can obtain from the PCA window);
b) save the CVA/DA scores (in MJ or PAST) and
compute Euclidean distances from those to
actually obtain Mahalanobis distances. If I am
correct (will check later), this can be done in
PAST (menu statistics - similarity and distance
indices) using the Euclidean distance option from
the imported CVA/DA scores, as your scores are
already in the transformed CVA/DA statistical
space and Euclidean distances should therefore be
the same as Mahalanobis distances.
>3. How should I interpret the discriminant and
>cross-validation scores MorphoJ produces?
The best introduction for biologists I know on
CVA/DA is Albrecht, 1992. You'll find the full
ref. in Kovarovic et al. (pdf in my webpage) and
in that paper and in Seetah et al. and Evin et
al. (again in my webpage) you'll find some
simplified considerations on CVA/DA and
references to more rigorous and sometimes more
technical papers such as those by Klingenberg &
Monteiro, Mitteroecker and Bookstein etc.
I also really like the intro on CVA/DA by
Strauss, 2010, again cited in Kovarovic et al.
Good luck
Andrea
>Thanks for your help,
>
>Dave Thulman
><mailto:dthul...@gmail.com>dthul...@gmail.com
>
>
>
>----- End forwarded message -----
>
>
Dr. Andrea Cardini
Researcher in Animal Biology, Dipartimento di
Scienze Chimiche e Geologiche, Università di
Modena e Reggio Emilia, l.go S. Eufemia 19, 41121 Modena, Italy
Honorary Fellow, Centre for Anatomical and Human
Sciences, University of Hull, Cottingham Road,
Hull, HU6 7RX, UK & University of York, Heslington, York YO10 5DD, UK
Adjunct Associate Professor, Centre for Forensic
Science , The University of Western Australia, 35
Stirling Highway, Crawley WA 6009, Australia
E-mail address: alcard...@gmail.com, andrea.card...@unimore.it
WEBPAGE: http://sites.google.com/site/hymsfme/drandreacardini
Summary of research interests at:
http://www.dscg.unimore.it/site/home/ricerca/aree-di-ricerca/evolution-taxonomy-and-forensics.html
FREE Yellow BOOK on Geometric Morphometrics:
http://www.italian-journal-of-mammalogy.it/issue/view/405
or full volume at:
http://www.italian-journal-of-mammalogy.it/public/journals/3/issue_241_complete_100.pdf
Editorial board for:
Zoomorphology:
http://www.springer.com/life+sciences/animal+sciences/journal/435
Journal of Zoological Systematics and
Evolutionary Research: http://www.wiley.com/bw/journal.asp?ref=0947-5745&site=1
Hystrix, the Italian Journal of
Mammalogy: http://www.italian-journal-of-mammalogy.it/
----- End forwarded message -----
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