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Subject: common allometric components and residual shape components
Date: Wed, 7 Mar 2012 07:27:41 -0500
From: [email protected]
To: [email protected]
Hi,
I have a question about common allometric components and residual shape
components, or CAC and RSC, and how RSCs relate to PCs generated from
size-corrected data.
So, the CAC is a regression line, calculated using a pooled within group
regression of coordinate data on size. And if so, is this line also
referred to as a pooled allometric vector? And will MorphoJ allow one to
use this vector in a regression with another variable, such as the RSC? Or
is it a better bet to obtain the allometric vector in another program,
such as R.
Using the residuals from that regression and doing a PCA, the PC1 is the
same as the RSC? Is this correct? If so, MorphoJ will certainly do this.
One more issue: doing PCA using R...I have problems with an error about
having too many variables (relative to the number or rows, I suppose). How
do I work around this in R?
Eric
U of Calgary
