Jack I find Edzer notation confusing, since evryone I know uses C0 for the bugget effect not the total sill of the semi-variogram model.
The correlogram relationship is a theoretical one but should hold provided the paricular gamma(h) is calculated using all the same samples at the total sill. According to Noel Cressie (Statistics for Spatial Data) the Cauchy Schwartz inequality should hold for every point on the calculated semi-variogram subject to all samples being used at the lag. You are probably getting greater than 1 because of clustered sampling (?) or non-Normality in your data. Isobel --- jack webster <[EMAIL PROTECTED]> wrote: > Hi > Thank you, for replying, but as you know the > theorical > relation between variogram and correlogram > r(h) = (C0-gamma(h))/C0 does not holds for > estimates! > I compute correlogrm with > r^(h) = (C0^-gamma^(h))/C0^ > (^ = estimate notation) > but in some lags r^(h) was grater than 1 !! > > Sincelely: webster > ======================================= > --- "Edzer J. Pebesma" <[EMAIL PROTECTED]> wrote: > > > jack webster wrote: > > > > >hello, > > >I need a good estimator for the Correlogram, > under > > 2nd > > >stationary condition, and a SPLUS program for > > >computing it (if there is). > > >Sincerely: Webster > > > > > > > > > > > Jack, you can use the S-Plus function acf() to > > compute > > autocorrelations from one-dimensional data. As > > you're > > on this list, you probably want it for 2-D or 3-D. > > For those > > data you can compute variograms. > > > > In S-Plus, library gstat (free; www.gstat.org) or > > the S-Plus > > SpatialStats module (commercial) are available for > > computing sample variograms and modelling > variogram > > functions. > > > > The correlogram can be computed from a variogram > by > > > > r(h) = (C0-gamma(h))/C0 > > > > with C0 the sill of the variogram and gamma(h) the > > semivariance (model) value. > > -- > > Edzer > > > > > * 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 [EMAIL PROTECTED] > > > > Signoff ai-geostats > > > __________________________________________________ > Do You Yahoo!? > Tired of spam? Yahoo! Mail has the best spam > protection around > http://mail.yahoo.com > > > * 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 [EMAIL PROTECTED] > > Signoff ai-geostats
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