Tag Archives: varimax

More North American Upper Treeline: Wilson-Luckman 2002, 2003

Apr 17, 2007 – 3:16 PM

In our continuing quest for a North American upper treeline chronology that exemplifies the IPCC AR4 claim that additional data since TAR shows “coherent behavior” across multiple indicators, we turn now to the upper treeline proxies of Wilson and Luckman, 2002, 2003. They collected 20 Engelmann spruce sites in British Columbia in 1998, which together […]

By Stephen McIntyre | Posted in Noamer Treeline | Comments (69)

Regression and Varimax Rotation

Apr 3, 2007 – 1:27 PM

I’ve been reading through some articles on altitudinal reconstructions by Rob Wilson and other Luckman students. The studies all follow a similar strategy as Wilson et al 2007 – principal components analysis; truncation to eigenvalues 1, varimax rotation and regression. It’s pretty obvious that these operations are all linear and if the linear algebra were […]

By Stephen McIntyre | Posted in Multivariate, Statistics | Also tagged , | Comments (36)

Varimax Rotation and the AMM

Mar 25, 2007 – 7:50 AM

While I was reading about rotated varimax PCA in connection with Rob Wilson’s article, I came across R.W. Houghton and Y.M. Tourre, 1992, Characteristics of Low-Frequency Sea Surface Temperature Fluctuations in the Tropical Atlantic, Journal of Climate Volume 5, Issue 7 (July 1992) pp. 765—772 url. They observed that a PC analysis applied to Atlantic […]

By Stephen McIntyre | Posted in Hurricane, Multivariate, Noamer Treeline | Also tagged | Comments (5)

Wilson et al 2007

Mar 24, 2007 – 10:59 AM

Rob Wilson has referred us to Wilson et al 2007. In addition to being an example of site selection, Wilson et al 2007 uses a type of principal components on a tree ring network – something that should be of interest to many CA readers – and an interesting illustration of non-Mannian statistical methods within […]

By Stephen McIntyre | Posted in Divergence, Multivariate, Noamer Treeline, Proxies | Also tagged | Comments (105)