## Re: [ai-geostats] A quasi-stationary framework...

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• The variogram is only the difference between the absolute values of the grade, so if you subtract the mean from every z(x), you will still have the same
Message 1 of 3 , May 7, 2005
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The variogram is only the difference between the absolute values of the
subtract the mean from every z(x), you will still have the same variogram?

----- Original Message -----
From: "Simone Sammartino" <marenostrum@...>
To: "Geostat newsgroup" <ai-geostats@...>
Sent: Wednesday, May 04, 2005 11:36 PM
Subject: [ai-geostats] A quasi-stationary framework...

It's me again!...:-))
My problem now is:
Assume Z(x) is not exactly stationary but its mean varies weakly in the
space...
Thus E[Z(x)]=m(x)...let's consider a new variable, said residual,
Y(x)=Z(x)-m(x), with zero mean.
Variogram for Z(x) is
(1) 2*Gamma(x)=E{[Z(x)-Z(x+h)]^2}-[m(x)-m(x+h)]^2
At this point the book says "...and it's easy to realize how variogram of
Y(x) is exactly the same of (1)..." How??!?!?!?
I tried everything but I did not manage to obtain the same result....
Anyone helping me?
Thanks as always
Simone

-----------------------------
Dr. Simone Sammartino
PhD student
- Geostatistical analyst
- G.I.S. mapping
I.A.M.C. - C.N.R.
Geomare-Sud section
Port of Naples - Naples
marenostrum@...
-----------------------------

____________________________________________________________
6X velocizzare la tua navigazione a 56k? 6X Web Accelerator di Libero!
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• Thank you for reply but I wanted to understand it in a pure formal mathematical framework... SimoneThe variogram is only the difference between the
Message 2 of 3 , May 10, 2005
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Thank you for reply but I wanted to understand it in a pure formal mathematical framework...
Simone

> The variogram is only the difference between the absolute values of the
> subtract the mean from every z(x), you will still have the same variogram?
>
> ----- Original Message -----
> From: "Simone Sammartino" <marenostrum@...>
> To: "Geostat newsgroup" <ai-geostats@...>
> Sent: Wednesday, May 04, 2005 11:36 PM
> Subject: [ai-geostats] A quasi-stationary framework...
>
>
> It's me again!...:-))
> My problem now is:
> Assume Z(x) is not exactly stationary but its mean varies weakly in the
> space...
> Thus E[Z(x)]=m(x)...let's consider a new variable, said residual,
> Y(x)=Z(x)-m(x), with zero mean.
> Variogram for Z(x) is
> (1) 2*Gamma(x)=E{[Z(x)-Z(x+h)]^2}-[m(x)-m(x+h)]^2
> At this point the book says "...and it's easy to realize how variogram of
> Y(x) is exactly the same of (1)..." How??!?!?!?
> I tried everything but I did not manage to obtain the same result....
> Anyone helping me?
> Thanks as always
> Simone
>
>
> -----------------------------
> Dr. Simone Sammartino
> PhD student
> - Geostatistical analyst
> - G.I.S. mapping
> I.A.M.C. - C.N.R.
> Geomare-Sud section
> Port of Naples - Naples
> marenostrum@...
> -----------------------------
>
>
>
> ____________________________________________________________
> 6X velocizzare la tua navigazione a 56k? 6X Web Accelerator di Libero!
> Scaricalo su INTERNET GRATIS 6X http://www.libero.it
>
>
>
>
>
>
> --------------------------------------------------------------------------------
>
>
> >* By using the ai-geostats mailing list you agree to follow its rules
> > ( see http://www.ai-geostats.org/help_ai-geostats.htm )
> >
> > * To unsubscribe to ai-geostats, send the following in the subject or in
> > the body (plain text format) of an email message to sympa@...
> >
> > Signoff ai-geostats
>
>
>
>

-----------------------------
Dr. Simone Sammartino
PhD student
- Geostatistical analyst
- G.I.S. mapping
I.A.M.C. - C.N.R.
Geomare-Sud section
Port of Naples - Naples
marenostrum@...
-----------------------------

____________________________________________________________
6X velocizzare la tua navigazione a 56k? 6X Web Accelerator di Libero!
Scaricalo su INTERNET GRATIS 6X http://www.libero.it
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