Tag Archives: orthogonal

More on "Naturally Orthogonal"

Apr 7, 2007 – 11:16 AM

I realize that not all CA readers are interested in multivariate methods and that dendroclimatologists want to “forget the math”, but I find it interesting to try to relate dendro and paleoclimate recipes to known statistical methodologies that you can read about in texts. I commented the other day on the form of Principal Components […]

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

Nature's Style: "Naturally Orthogonal"?

Apr 4, 2007 – 12:25 PM

Wilson and Luckman 2003 observe: The first PCs from the RW and MXD PCA are naturally orthogonal (r = —0.006) over the 1900—1991 period suggesting the in’?fluence of different forcing mechanisms upon these parameters. They move on without pausing here, but this point should not be left without a commentary. The issue here is one […]

By Stephen McIntyre | Posted in Multivariate, Noamer Treeline, Proxies | Also tagged , | Comments (26)

MBH and Partial Least Squares

Jun 13, 2006 – 8:35 AM

Right now, I’m working on two main projects where I intend to produce papers for journals: one is on the non-robustness of the “other” HS studies; the other is on MBH98 multivariate methods. The latter topic is somewhat “in the news” with the two Bürger articles and with the exchange at Science between VZ and […]

By Stephen McIntyre | Posted in MBH98, Multivariate, Replication, Statistics | Also tagged , , , , , , , | Comments (41)

More Linear Algebra

Feb 13, 2006 – 4:08 PM

I’m not sure that there’s a huge demand for more linear algebra on MBH98, but here’s the rest of the proof that the NH temperature index in an MBH98-type calculation is simply a linear combination of proxies and, when only one temperature PC is reconstructed, the weights are proportional to the correlation between each proxy […]

By Stephen McIntyre | Posted in MBH98, Replication, Source Code | Also tagged , | Comments (16)