Thanks Colin and Goran for your replies. Colin, we've actually got
several thousand optic disc photos which I plan to do a trace of, but
thanks for the information anyway.
One other question;
I've read that you can break down Fourier co-efficients using principal
component analysis (and have actually been having a play with the
'Shape' software available on this site). I understand that PCA is a
data reduction technique. However, I don't come from a maths background
and I'm having trouble visualising what PCA actually gives you in the
break-down analysis of a shape. For example, using this software, for a
sample of outlines
Eigenvalue Proportion(%) Cumulative(%) > 1/96
Prin1 3.554525E-004 53.9578 53.9578 *
Prin2 2.099497E-004 31.8704 85.8282 *
Prin3 6.445964E-005 9.7850 95.6132 *
Can someone explain (in lay terms) what the numbers actually mean (in my
situation of an optic disc)? Are they vectors describing direction and
magnitude? I can't seem to find any good resources online that explain
PCA without a considerable background maths knowledge basis (maybe there
is no simple way!)
Is PCA an accepted scientific data analysis technique?
Thank you.
Paul
[EMAIL PROTECTED]
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