Hi
If you read the description of "varcov.spatial" you'll see that it
is
used to *predict* a covariance matrix, based on the parameters of the
covariance function. So you don't need the oebserved data, you need
parameters for the covariance function.
Regards
EJ
On Thu, 2003-04-17 at 05:43, Yan Yu wrote:> THanks for the suggestion.
> I have a Q when trying to use it..
> I want to get covariance matrix from the data set in hand..
> basically i have a rainfall data set in a 15x12 points.
> i try to use:
> "varcov.spatial", but it seems that the input to that function is
just
> coordinate list of the data values, not the actual data at those points.
> I am confused by this?
> How come the covariance matrix or variogram matrix is irrelevant to the
> the data value, but only depends on the data configuration(i.e., the
> sampling locations)?
> I found other covariance functions, like cor.number or cov.spatial is
> similar in the sense that they only ask for data locations, not data
values..
>
> Any hints or pointer is appreciated!
> yan
>
>
> On 17 Jan 2003, Ernesto Jardim wrote:
>
> > Hi
> >
> > I'm working with geostatistics and I use geoR package, which I
find very
> > good. However it doesn't implement the classic geostatistics but a
> > "model based geostatistics" as proposed by Peter Diggle and
team.
> >
> > R news of June 2001 has an article about geoR by Paulo Ribeiro, the
main
> > developer, that you might like to take a look at. I find this number
of
> > Rnews a very good source for someone willing to use geostatistics in
R.
> >
> > Regards
> >
> > EJ
> >
> > On Fri, 2003-01-17 at 05:06, Yan Yu wrote:
> > > Hi, all,
> > > Have anyone used kringing included in R? How is it?
> > > Does it handle anisotropy data well?
> > > How does it compare with Kriging in Arc/Info? or other
geostatistics
> > > software customized to do kriging or other geostatistics
functions?
> > >
> > > I tried Easykriging, a geostatistics tool developed for Matlab.
It has
> > > very nice GUI, but it does not provide library which i can call
in my programs.
> > > so it is good for doing it mannually for small number of data
set. but if
> > > i have large number of data set, and i want to automate the
kriging
> > > process for those data set, Does anyone have good recommendation
on what
> > > software to use? something that can be called in c/c++ code(or
matlab)
> > > and freeware:) is preferred..
> > >
> > > Thanks a lot in advance for any input.
> > > yan
> > >
> > > ______________________________________________
> > > R-help at stat.math.ethz.ch mailing list
> > > http://www.stat.math.ethz.ch/mailman/listinfo/r-help
> >
