I have a follow up question regarding the range parameter specified for
the gaussian variogram model in gstat..
First, thank you to Jaime Grion who riplied...
Dear Kerry, if you write in the option model "Gau" you just have to
specify 200 [for the range].
However, when I fit the variogram and the fitted value returns "200" as
the range parameter, the variogram looks like the true range exceeds
200. Is the returned range parameter the "practical range" = the value
at which this model reaches 95% of its asymptotic value or the value
where spatial correlation ceases to exist?. In Bivand, et. al's book
"Applied Spatial Data Analysis with R", the authors state that the
practical range for the gaussian variogram model is sqrt(3)*a where a is
the range parameter for most other models. So my question remains. Is
the fit giving me the range or the practical range?
Thanks,
Kerry
Kerry Ritter wrote:
Hi all. I have what I hope is a quick question concerning the use of
"fit.variogram" in"gstat". If you assume a a Spherical model for the
variogram and the estimated range is say 200m and then you switch
models to a Gaussian but want to keep the range fixed at 200m, would
you specify 200 for the range parameter or 200/sqrt(3)?
Thanks,
Kerry
**********************
Kerry Ritter, Ph.D.
statistician
Southern California Coastal Water Research Project
3535 Harbor Blvd., Suite 110
work: 714-755-3210
cell: 714-420-3346
fax: 714-755-3299
email: ker...@sccwrp.org
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--
**********************
Kerry Ritter, Ph.D.
statistician
Southern California Coastal Water Research Project
3535 Harbor Blvd., Suite 110
work: 714-755-3210
cell: 714-420-3346
fax: 714-755-3299
email: ker...@sccwrp.org
_______________________________________________
R-sig-Geo mailing list
R-sig-Geo@stat.math.ethz.ch
https://stat.ethz.ch/mailman/listinfo/r-sig-geo
