Hi, Dan:
On 10/1/2012 8:07 PM, Dan Bebber wrote:
Please be assured, I really did "RTFM" (i.e. Pinheiro & Bates) as well as all the online sources,
and have accessed the codes of the corStruct functions, but they do not reveal how the "metric"
argument is used. Therefore, I can't reprogram to include "haversine" distance, as seen in the ramps
package.
Smith et al. (2008) write "The spatial correlation structures in nlme are not
directly used because they do not allow great circle distance, which is very commonly
needed for spatial data" so there may be a case for adding this functionality to
nlme.
If anyone knows a way in to the relevant code, please let me know.
Thanks for the clarification and for your persistence in this
issue. Others clearly have been asking for an enhancement of this nature.
I assume you've checked and confirmed that "ramps::corRSpher", as
suggested by David Winsemius, will NOT do what you want. If so, I
suggest you subscribe to "R-sig-mixed-models" (per r-project.org ->
"Mailing Lists"), and post your question, citing Smith et al., to there.
When you do, I suggest you include cc: Douglas Bates
<ba...@stat.wisc.edu>.
I'm sorry I can't help more, but I hope you will soon find a
solution to this problem.
Best Wishes,
Spencer
Thanks
Dan
Reference
Smith BJ, Yan J & Cowles MK 2008. Unified Geostatistical Modeling for Data
Fusion and Spatial Heteroskedasticity with R Package ramps. Journal of Statistical
Software 25(10)
________________________________________
From: David Winsemius [dwinsem...@comcast.net]
Sent: 01 October 2012 17:32
To: Spencer Graves
Cc: Dan Bebber; r-help@r-project.org
Subject: Re: [R] nlme: spatial autocorrelation on a sphere
On Oct 1, 2012, at 8:34 AM, Spencer Graves wrote:
On 10/1/2012 12:38 AM, David Winsemius wrote:
<snip>
LMCTVTFY: http://cran.r-project.org/web/views/Spatial.html
What's LMCTVIFY?
Please accept my apologies for attempting to be cute and I also apologize to Mr
Bebber for reading his request far too quickly. I was trying to use (C)RAN
(T)ask (V)iews as a verb.
LMGTFY for LMCTVIY produced only LMGTFY, at least for me. There's space for it on
Wikipedia ("RTFM") after LMGTFY (which I found using LMGTFY Wikipedia).
I don't think it warrants being enshrined. I might also have written: require(sos);
findFn("metric spherical latitude longitude") might produce. In this instance that
approach found the ramps::corRSpher function, which has a "haversine" metric, much more
quickly than did my subsequent efforts with RSeek, which I conducted after I realized that Bebber
had already made a good faith effort at identifying resources.
--
David Winsemius, MD
Alameda, CA, USA
--
Spencer Graves, PE, PhD
President and Chief Technology Officer
Structure Inspection and Monitoring, Inc.
751 Emerson Ct.
San José, CA 95126
ph: 408-655-4567
web: www.structuremonitoring.com
______________________________________________
R-help@r-project.org mailing list
https://stat.ethz.ch/mailman/listinfo/r-help
PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
and provide commented, minimal, self-contained, reproducible code.
