On Wed, 2003-09-10 at 08:33, [EMAIL PROTECTED] wrote: > Dear Morphometricians: I am working on a systematic study of a palm > genus, Geonoma. The species of current interest, G. interrupta, is quite > a large palm, and so herbarium specimens (the source of my data) are > usually fragmentary and not suitable for traditional morphometrics. I
Good luck. Plant folks over the years have met with a good degree of frustration with geometric morphometrics mainly for the reason mentioned below. > want to use landmark data from the flowering branches, specifically the > pits in which the flowers are borne. There is quite a lot of variation > in the spiral arrangement of these pits. A critical aspect of landmark-based GM is the assumption of either evolutionary/developmental or functional homology of the landmarks across specimens. That is, it is assumed that landmark 3 is the "same" structure on every specimen (though similarly-dimensioned, unlabelled point sets can be analyzed by permutation). This is not meant to discourage, but rather to let you know up front some of the requirements for the most common types of analyses you will see - Procrustes superimpositions + MV analysis of residuals. You might look at work by R J Jensen and students on oak leaves and such. > > Anyway, here is my question (I am a complete novice in landmark > analysis!): I have taken digital images (through a stereomicroscope) of > the flowering branches and pit arrangement. How can I obtain x,y > coordinates from these images? I had thought to use Image J, but this > may not work. There is none better for 2D data acquisition than Rohlf's tpsDig available at the Stony Brook website: http://life.bio.sunysb.edu/morph My $0.02, ds > > Thanks. Andrew Henderson > == > Replies will be sent to list. > For more information see http://life.bio.sunysb.edu/morph/morphmet.html. -- Dennis E. Slice, Ph.D. Department of Biomedical Engineering Division of Radiologic Sciences Wake Forest University School of Medicine Winston-Salem, North Carolina, USA 27157-1022 Phone: 336-716-5384 Fax: 336-716-2870 == Replies will be sent to list. For more information see http://life.bio.sunysb.edu/morph/morphmet.html.
