size standardization in EFA

[morphmet]

-------- Original Message --------
Subject: size standardization in EFA
Date: Wed, 7 Oct 2009 09:16:49 -0700 (PDT)
From: Thomas DeWitt <tdew...@tamu.edu>
To: <morphmet@morphometrics.org>

I want to hear opinions as to whether centroid size is a reasonable
criterion for size standardization in EFA.
Normally, size in EFA is standardized to the area of the first harmonic
ellipse.
Standardizing to ellipse area yields for the first harmonic quartet:
A=1, B=C=0, and |D|<1, which is a tidy property.

Is there any reason one method of size standardization should be
preferred over the other?
It seems if standardized to centroid size then principle components of
the harmonic coefficients are more purely "shape variables".

-Thom DeWitt

   >=))))(º>     >=))))(º>     >=))))(º>     {|||||º>
                         ^   ^             L  L         L  L

Dr. Thomas J. DeWitt, Associate Professor
Departments of Wildlife & Fisheries Sciences
  and Plant Pathology & Microbiology
Interdisciplinary Research Program in Ecology & Evolutionary Biology
Texas A&M University
2258 TAMU
College Station, TX 77843-2258

Tel. (979) 458-1684 (office)
Tel. (979) 845-7522 (lab)
Fax (979) 845-4096
E-mail tdew...@tamu.edu
Web http://wfsc.tamu.edu/faculty/tdewitt/webpage.htm
TAMU Map to DeWitt lab & office:
http://www.tamu.edu/map/gifs/detail/FGHB.gif



--
Replies will be sent to the list.
For more information visit http://www.morphometrics.org