A "sparring partner" on Twitter, @CMastication asked a question about PCA the other day & in looking for quick riposte I realised that I have been rather banging on here about the Copula. I couldn't find a reference here at all to PCA! So I need to fix that since I am a huge fan and big user of PCA. Of course the leading thinker in the space is Professor Croux at UKL here in Belgium who is an adviser to my firm.
Below some good references to PCA and what it is for, when to use it & indeed why we use it. One of my other motivations for doing this, is that exactly the same question came up of a LinkedIn Group during my recent summer holidays which I have to say I answered rather cursorily, for which I am apologetic and hope this post will go someway to putting that right.
I hadn't been aware of this last author before I did this (which, of course is part of the purpose of doing it!)but the material looks really cool! All part of this visualisation & 'data wrangling' "thing" across the pond, where I believe the robust approach of Professor Croux could make a great contribution.