AI-GEOSTATS: Choosing Lag Distance and Angular Tolerance
Hello dears I have a spatial data set contaning n=262 observarion (The variable of interest is Rate of Tuberculosis in 262 counties of Iran). I want to fit some models to Directional semi-variograms,and then build anisotropic semi-variogram. Then questions are - Is there any rule for choosing Lag Distance and Angular Tolerance? -Also,how we can balance between Lag Distance and Angular Tolerance? -Do you agree that both must be very small,as possible?(Such that number of pairs in each lag20, for example) Thank you Yadollah Waghei Dep.of Biostatistics Tarbiat Modarres Univ.(Tehran)Po.Box: 14115-111 Tel:8011001-3872 Fax:8007989 ___ Visit http://www.visto.com/info, your free web-based communications center. Visto.com. Life on the Dot. -- * 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
AI-GEOSTATS: Need to SPLUS functions for Universal Kriging and Simulation...
Hello, Dear Members I work in Spatial Statistics context, and write my programs in SPLUS. Now I need to user written SPLUS functions for both Universal Kriging, and simulation random fields in 2-dimensional space. For simulation I have seen the article: E. Pardo_Iguzquiza and M. Chica-Olm.(1993) The Fourier Integral Method: An Efficient Spectral Method for Simulation Random Fields, Mathematics in Geology Vol.25 No.2 (But I need to SPLUS functions to do it, if written by someone) Thank you Waghei Dep.of Biostatistics Tarbiat Modarres Univ.(Tehran)Po.Box: 14115-111 Tel:8011001-3872 Fax:8007989 ___ Visit http://www.visto.com/info, your free web-based communications center. Visto.com. Life on the Dot. -- * 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
AI-GEOSTATS: Marrons I Statistic
Hello AI-Geostats members
I saw Marrons I Statistic in GS+ Software. It is an statistic computed in each lags as
follow:
N(h){sum(Zi*Zj)/sum(Zi^2)}
This statistics and its plot arise for me two problem:
- Is it the correlation function?
- How can interpret this statistics or its plot?
(Also I think that N(h) needs the power -1, i.e 1/N(h) is the correct not N(h)!).
I have another question about GS+ method for semi-variogram model fitting:
--- By which method GS+ estimates the parameters of semi-variogram? (By Least Square,
Generalized Least Square, Maximum Likelihood,...?)
Yadollah Waghei
Dep.of Biostatistics
Tarbiat Modarres Univ.(Tehran)Po.Box: 14115-111
Tel:8011001-3872 Fax:8007989
___
Visit http://www.visto.com/info, your free web-based communications center.
Visto.com. Life on the Dot.
--
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* As a general service to the users, please remember to post a summary of any useful
responses to your questions.
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AI-GEOSTATS: Sill in the Rational Quadratic Semivariogram Model
Hello, AI_Geostats members In some model for variograms the Range (the distance at which dependency is disappear) is differ from the Range parameter in the model. For example in the exponential semivariogram model (bellow) range = 3 * (range parameter) (reference: the user manual of GS+ software) My question is that what is the relationship between range and range parameter in Rational Quadratic Semivariogram Model? Cressie,1993 (page 61) has written the model as: g(h) = c0 + cr*(h^2)/(1 + h^2/ar) where cr and ar are the sill parameter and range parameter. Thank you for your attention. Yadollah Waghei Dep.of Biostatistics Tarbiat Modarres Univ.(Tehran)Po.Box: 14115-111 Tel:8011001-3872 Fax:8007989 ___ Visit http://www.visto.com/info, your free web-based communications center. Visto.com. Life on the Dot. -- * 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
AI-GEOSTATS: Simulation Spatial Data with anisotropy in Range
Hi AI-Geostats Member Do you know how I can simulate a 2-D spatial Data set (of type geostatistics), which sill and nugget effect are constant but the range vary with direction (anisotropy in range). Note that I need the range vary irregular, not in a regularar shape such as ellipse. (I have an extention of elliptic anisotropy (of range) and want to show, by simulation, it works better than elliptic anisotropy.) Thank you: Yadollah Waghei Dep.of Biostatistics Tarbiat Modarres Univ.(Tehran)Po.Box: 14115-111 Tel:8011001-3872 Fax:8007989 ___ Visit http://www.visto.com. Find out how companies are linking mobile users to the enterprise with Visto. -- * 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
AI-GEOSTATS: Marrons I Statistic (Again)
Hello AI-Geostats members
I set this mail to AI-GEOSTATS , But I did not recieve any response, therefore I send
it again:
I saw Marrons I Statistic in GS+ Software. It is an statistic computed in
each lags as follow:
N(h){sum(Zi*Zj)/sum(Zi^2)}
This statistics and its plot arise for me two problem:
- Is it the correlation function?
- How can interpret this statistics or its plot?
(Also I think that N(h) needs the power -1, i.e 1/N(h) is the correct not
N(h)!).
I have another question about GS+ method for semi-variogram model fitting:
--- By which method GS+ estimates the parameters of semi-variogram? (By
Least Square, Wieghted Least Square, Maximum Likelihood,...?)
Yadollah Waghei
Dep.of Biostatistics
Tarbiat Modarres Univ.(Tehran)Po.Box: 14115-111
Tel:8011001-3872 Fax:8007989
___
Visit http://www.visto.com.
Find out how companies are linking mobile users to the
enterprise with Visto.
--
* 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
AI-GEOSTATS: Estimating the fixed Sill in the Elliptic Anisotropy
Hi, AI-Geostats member In Elliptic Anisotropy we suppose that the Sill parameter of Variogram is fixed and the Range parametre is varying with direction, in an ellipce. But in practice, usually Sill is also depends to direction (more or less). My question is that: How can we estimate Sill and Range in all directions by supposing that the sill is fixed? (With traditional methods in statistics: OLS, WLS,..). NOTE that in the traditional Variogram Model fitting, where we estimate the range and the sill in each direction ,seperately, we yield different sills in different directions, EVEN THE DATA SIMULATED FROM AN ISOTROPIC RANDOM FIELD! Yours Sincerely: Y. Waghei Dep.of Biostatistics Tarbiat Modarres Un. Tehran Tel:8011001-3872 ___ Visit http://www.visto.com. Find out how companies are linking mobile users to the enterprise with Visto. -- * 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
AI-GEOSTATS: Anisotropy with varying Range and Sill
Hi AI-Geostats member I have an Anisotropic Spatial Data Set on which,Sill and Range (and also nugget effect) are both varying with direction, I need a method or refrence article for modelling the variogram structure of such data in 2-Dim. space. Please introduce a method and/or a reference article, if you know. Yours Sincerely: Y. Waghei Dep.of Biostatistics Tarbiat Modarres Un. Tehran Tel:8011001-3872 ___ Visit http://www.visto.com. Find out how companies are linking mobile users to the enterprise with Visto. -- * 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
AI-GEOSTATS: geostatistcs prorram(MSc level)
Hi Do you know ,at which university geostatistics program at Msc level is taught? I need the list of its courses (or its program) sincerely: Y. Waghei Birjand University + + To post a message to the list, send it to ai-geostats@jrc.it + To unsubscribe, send email to majordomo@ jrc.it with no subject and unsubscribe ai-geostats in the message body. DO NOT SEND Subscribe/Unsubscribe requests to the list + As a general service to list users, please remember to post a summary of any useful responses to your questions. + Support to the forum can be found at http://www.ai-geostats.org/
AI-GEOSTATS: books and software on Spatial-temporal analysis
Hi do you know is there any book or software on the spatial-temporal analysis, or a book contaning spatial-temporal covariance estimation? + + To post a message to the list, send it to ai-geost...@jrc.ec.europa.eu + To unsubscribe, send email to majordomo@ jrc.ec.europa.eu with no subject and unsubscribe ai-geostats in the message body. DO NOT SEND Subscribe/Unsubscribe requests to the list + As a general service to list users, please remember to post a summary of any useful responses to your questions. + Support to the forum can be found at http://www.ai-geostats.org/
AI-GEOSTATS: need to refrence about ANISOTROPY
hi I am statistician. I want to work in the area of Anisotropic variogram or covariogram models. I need to new refrences. Please give me (or address) refrence for anisotropy. Sincerely: Yadollah Waghei Department of Statistics Birjand University - Iran Mobile: 09151633142
