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MomX / Momocs

:dove: Morphometrics using R
http://momx.github.io/Momocs/
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LDA vs. PCA #160

Closed lrocax closed 7 years ago

lrocax commented 7 years ago

Is it possible to use LDA directly on the on the efourier results? In the help I noticed that you perform the LDA on the PCA results, why? what is the advantage?

vbonhomme commented 7 years ago

you can access Fourier coefficients (or any other coefficient after any morphometric operation) with yourCoe$coe eg, with magrittr's pipes : bot %>% efourier %$% coe

PCA "orthogonalizes" these coefficients and it helps a lot, particularly with lda (in MASS::). It avoids collinearity issues.

hope this helps (and sorry for the delay)

v