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
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