Tag Archives: RegEM

RegEM PTTLS Ported to R

I’ve now ported my emulation of Schneider’s RegEM PTTLS to R and benchmarked it against Jeff’s Matlab as shown below. I caution readers that this is just an algorithm. There are other ways of doing regressions and infills. The apparent convergence to three PCs noted by Roman is still pending as a highly interesting phenomenon. […]

Porting RegEM to R #1

I’ve transliterated relevant Tapio Schneider code into R (pttls.m) and parts of regem.m that seem relevant at present. Jeff Id has extracted a variety of intermediates from his Matlab run and I’ve fully reconciled through two steps with remaining differences appearing to be probably due to transmission rounding. My dXmis statistic at step one was […]

Interaction of Infilling on Std Deviation

Standardization in Mannian algorithms is always a bit of an adventure. The bias towards bristlecones and HS-shaped series from the impact of Mann’s short segment standardization on his tree ring PCs has been widely publicized. Smerdon’s demonstration of defects in Rutherford et al 2005, Mann et al 2005 and Mann et al 2007 all relate […]

The Two Jeffs on Emulating Steig

The two Jeffs ( C and Id) have interesting progress reports on emulating Steig using unadorned Tapio Schneider code here. Check it out. One of the first questions that occurred to third party readers was whether RegEM somehow increased the proportional weight of Peninsula stations to continental stations as compared to prior studies. Jeff C […]

Smerdon et al 2008 on RegEM

Smerdon et al 2008 is an interesting article on RegEM, continuing a series of exchanges between Smerdon and the Mann group that has been going on for a couple of years. We haven’t spent much time here on RegEM as we might have. I did a short note in Nov 2007 here. In July and […]

Antarctic RegEM

Image by mark van de wouw via Flickr For discussion of new study. by Steig (Mann) et al 2009. Data: Data sets used in this study include the READER and AWS data from the British Antarctic Survey. SI Tables 1 and 2 provide listings. They leave out station identifications (a practice that “peer” reviewers, even […]

Mann and Perfect Reconstructions

I finally turned over a few stones in Mann’s EIV reconstructions, little suspecting the perfection that awaited me in the cave using the simple and unassuming alter ego shglfulihad_smxx. The figure below compares the SH reconstruction to the smoothed (SH) iHAD instrumental version. From the frail instruments of speleothems, bristlecone ring widths and upside-down sediments, […]

Mann 2008 – Replication

Do not post anything other than programming comments. Absolutely no piling on please.

Re-Visiting RegEM: Rutherford et al 2005

Mann et al 2007 is a new RegEM version, replacing the RegEM calculations of Rutherford et al 2005. The logic is not entirely self-contained and so I re-visited some of our previous comments on Rutherford et al here here here here . I’m going to reprise two issues today: Collation Errors, a small but amusing […]

Jean S on Rutherford et al 2005

Jean S has sent the following longer contribution on Rutherford et al 2005. I always appreciate Jean S’s thoughtful comments (which is no secret to readers here). So enjoy. JeanS: Now since the review of Burger and Cubash [BC06 here after] put Rutherford (2005) [R05] back on the table, there is an issue to which […]

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