Dear Edzer,
Thanks for the answer, but I still have problems.....
II want to apply the indicator simple kriging with varying local mean,
considering secondary exaustive information.
So, with the command subset I split the primary attribute belong to the
respective class of the secondary information.
for instance:
Then I evaluate the percentage of value smaller than a threshold value, and
I obtain an exaussive set of soft indicator data, defined as:
y(u;zk)= Prob {Z(u)<=zk : secondary information
at u} (test: Goovaerts - pag. 307)
with this value I calculate the residual respect at Indicator data that
account for all available informations, and bulid the residual semivariogram.
Using that one, I want apply the simple indicator kriging, with the command
newdata=grd, model = res.4thCd.1Ni.model, beta=VECTOR)
I use a local mean, but I have problems
than, I use a constant mean, and the error is:
"gstat: value not allowed for: covariance from non-transitive
variogram not allowed "
Theory give that in steady assumption, we have:
C(h)=C(0)-gamma(h)
Can I put that in command krige?
Help me, please..... I ended my ideas........................
grazie
Cristiano
----Messaggio originale----
Da: edzer.pebesma at uni-muenster.de
Data: 10/05/2009 22.41
A: "facrimas at libero.it"<facrimas at libero.it>
Cc: <mike.elliott at openreach.co.uk>, <r-sig-geo at stat.math.ethz.ch>
Ogg: Re: [R-sig-Geo] indicator simple kriging with varying local mean on
gstat
The simplest solution might be to just (simple) krige the residuals, and
add them to your known varying mean.
Please be aware that this "model" suggests residuals have mean-dependent
variance (p * (1-p)), and thus using a single variogram model for the
full set of residuals is not in accordance with theory.
I guess that this problem is larger than the one you mention --
covariances are simply derived from variograms that reach a sill by C(h)
= gamma(inf) - gamma(h).
--
Edzer
facrimas at libero.it wrote:
Dear guys,
I want to use the indicator simple kriging with varying local mean on
gstat.
Do you have a script example about it?
I do not understand which is the local mean that I have to put in the
command
of simple indicator kriging.....
I do not also well understand whether if it is posssible to use the
semivariogram model in SK, because theory tells that it need the