Oliver
It would be helpful for those of us who might wish to reply to this post
to clarify if you are referring to the output from morphometrika (as
suggested by the title of your email) or morphologika (as suggested by
the content of your message). In case you meant Morphologika, I have
just run a file of 26 3d landmarks to test your assertion but have
failed to replicate your problem. Please feel free to contact me
directly if you think it might be helpful.
All the best,
Dr Una Vidarsdottir
[EMAIL PROTECTED]
Quoting morphmet <[EMAIL PROTECTED]>:
My e-mail for replies: [EMAIL PROTECTED]
Dear list members:
using the software morphologika I came across a problem regarding the
evaluation of the variables, which determine the different PCs in PCA.
In total, I set 26 3D landmarks, but in the output file there are only
75 (instead of 78) variables listed. Hence, I was wondering, what these
different variables actually mean. Am I right that variable 1 is the x-
coordinate of landmark 1, variable 2 = y-coordinate of lm 1, variable 3
= z-coordinate of lm 1, variable 4 = x-coordinate of lm 2, variable 5 =
y-coordinate of lm 2, and so on?
I actually would like to assess the influence of each landmark on each
PC by inspecting the eigenvectors of each variable for that component.
However, since I am not sure what the listed 75 variables actually mean,
I would like to ask any of you to give me an advice. Furthermore, I was
wondering whether it is possible to use the magnitude of the listed
correlation coefficient between both the variable and the PC to see,
which variables explain most of the respective PCs. In conventional PCA
it is recommended (as a rule of thumb) to consider all the correlations
> 0.5 as important and to discard all the variables in the
inerpretation, which have lower correlations with the respective PC. I
was wondering, whether this criterion is also applicable here.
I will be very glad if anybody can give me an advice on how to proceed.
I'll summarize the replies and post them to the mail server.
My e-mail for replies is: [EMAIL PROTECTED]
My best wishes and thanks,
Oliver Betz
Zoology Dptmt.
University of Tübingen
Germany
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For more information visit http://www.morphometrics.org
--
Dr Una Strand Vidarsdottir
Evolutionary Anthropology Research Group
Department of Anthropology
University of Durham
43 Old Elvet
Durham DH1 3HN
tel:0191-3346176
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For more information visit http://www.morphometrics.org
