although I would like to wait for Paulo's comments, here are my two brief remarks:
1. if your data set is large, say over 3000 observations, and you want to use kriging, you'd better use kriging in a local neighbourhood. I think geoR does not provide this, another R package that does so is package gstat. The quote you mention ignores this common practice. 2. if your data are in lat/lon, you may want to project them first -- to my knowledge all geostats software assumes data in a plane (or 3D data, but not on a sphere): one unit in x direction should equal one unit in y direction. In lat/lon, it generally doesn't.
Best regards, -- Edzer
Marcelo Alexandre Bruno wrote:
Dear list-members
I try to run geoR for generate interpolation maps. My data is: x(longitud, decimal degree),y(latitud, decimal degree),z(Sa, acoustic parameter, limits range is 0 to 1000000, extremely skewed, represent backscatering echoes signals of fish schools). The dataset is 3007 nautic miles of sampling!
The analysis is run according to steps of Dr. Paulo
Justiano's homepage
http://www.est.ufpr.br/~paulojus/geoR/geoRdoc/geoRintro.html#starting
.
When kriging run, consume all memory of system, (R.bin with only geoR consumes 86.8mb!! in Athlon
xp1.6GHz, Linux redhat 9.0, 250mb + swapp 541mb).
Is there something wrong (possible newbie question)
or its possible vectorizing computations to
reduce memory consume?
"The necessary reliance on a n by n matrix, where n represents the number of observations, greatly impedes traditional spatial statistics from handling larger sample sizes." published from: Pace, R. Kelley, and Ronald Barry, "Fast CARs," Journal of Statistical Computation and Simulation, Volume 59, Number 2, 1997, p. 123-147.
This is the case?? (Apologies for my long msg.) Thanks for all.
===== ## ~~~~~~~ Ocean�logo ~~~~~~~ ## # Marcelo Alexandre Bruno # Linux User: 124592 # P�s-gradua��o Oceanografia Biol�gica # FUNDACAO UNIV. FEDERAL do RIO GRANDE # Departamento de Oceanografia # Lab. de Tecnologia Pesqueira e Hidroac�stica # AV. IT�LIA km 8 s/n - CARREIROS # 96201-900 (0xx53) 2336528 # Rio Grande - RS - BRAZIL ## ---------------------------------------- ##
Yahoo! Mail - o melhor webmail do Brasil http://mail.yahoo.com.br
--
* To post a message to the list, send it to [EMAIL PROTECTED]
* As a general service to the users, please remember to post a summary of any useful responses to your questions.
* To unsubscribe, send an email to [EMAIL PROTECTED] with no subject and "unsubscribe ai-geostats" followed by "end" on the next line in the message body. DO NOT SEND Subscribe/Unsubscribe requests to the list
* Support to the list is provided at http://www.ai-geostats.org
-- * To post a message to the list, send it to [EMAIL PROTECTED] * As a general service to the users, please remember to post a summary of any useful responses to your questions. * To unsubscribe, send an email to [EMAIL PROTECTED] with no subject and "unsubscribe ai-geostats" followed by "end" on the next line in the message body. DO NOT SEND Subscribe/Unsubscribe requests to the list * Support to the list is provided at http://www.ai-geostats.org
