I'm currently working on a paper that deals with the problem of
over-parameterizing PCA in morphometrics. The recommendations that I'm
making in the paper are that you should try to have at least 3 times as
many samples as variables. That means that if you have 10 2D landmarks,
you should have
I found your message in EDMA analyses post.
I am having recently done the problem of craniofacial differences.
Could you share an edmaware for me?
Looking forward to your reply.
在 2014年11月19日星期三 UTC+8上午12:53:52，Cole, Theodore M.写道：
> There's a far more up-to-date edma program called edmaware that
在 2014年11月19日星期三 UTC+8上午12:53:52，Cole, Theodore M.写道：
> There's a far more up-to-date edma program called edmaware that I can send
> you. If that doesn't fix your problem, you could send me a couple of your
> files and I could try them here. I'll send a download link later today.
>
> Tim Cole
Will,
I’m not quite sure what over-parameterizing means in the case of PCA, as it is
simply a rigid-rotation of the dataspace and does not provide parameters for
statistical inference.
As for the distribution of eigenvalues, this of course is based on the
underlying covariance matrix for the
Just to comment.
While it is worthwhile to investigate these issues, in my experience same sizes
are limited not because investigators are NOT willing to measure more
specimens, but there are no additional specimens to include in the analysis,
especially for studies based on natural
I think a few topics get mixed up here.
Of course, a sample can be too small to be representative (as in Andrea's
example), and one should think carefully about the measures to take. It is
also clear that an increase in sample size reduces standard errors of
statistical estimates, including
Hello,
I'm an archaeologist who works on artifacts in North America. There are not
many of us that use LGM, but even we can't seem to agree on how many LMs
are appropriate. Because I use discriminant function analysis as the
workhorse for discriminating groups of artifacts, I worry about the
