Thanks to everyone for the quick replies! My main question was about the
phylogenetic PCA.
Ryan: yes my data are landmark configurations after Procrustes
superimposition. I understand allometry still has an effect after
Procrustes, so I have regressed centroid size on shape and used the
Marshall
Cc: morphmet@morphometrics.org
Subject: Re: [MORPHMET] PC Ranks in Evolutionary PCA
Hi Alex,
I'm assuming that your shape data are landmark configurations that have
been subjected to a Procrustes superimposition. is that correct?
If so, I dont think the regression you described
@morphometrics.org
Subject: Re: [MORPHMET] PC Ranks in Evolutionary PCA
Hi Alex,
I'm assuming that your shape data are landmark configurations that have been
subjected to a Procrustes superimposition. is that correct?
If so, I dont think the regression you described is really necessary-
Procrustes
Research Professor, Anthropology
Stony Brook University
-Original Message-
From: Ryan Felice [mailto:ryanfel...@gmail.com]
Sent: Friday, March 27, 2015 7:34 AM
To: Alex Marshall
Cc: morphmet@morphometrics.org
Subject: Re: [MORPHMET] PC Ranks in Evolutionary PCA
Hi Alex,
I'm assuming
Phylogenetic PCA has many unusual properties, and does not remove the effects
of phylogeny. Yes, it is the case that the variance of the scores on the first
phylogenetic principal component can be higher than the second PC. We recently
had a paper in the Hystrix morphometrics volumes about
Hello everyone,
I'm a MSci student new to morphometrics and this group. I'm studying
morphological integration in squamate crania and one of the things I'd like to
do is an Evolutionary PCA of all my species, accounting for phylogeny and
allometry.
I think I do this correctly but in the PCA
