Huge kriging weights when using kriging with external drift in gstat
Right, I believe the linear model without sill -- vgm(1, "Lin", 0) -- does work; note that the 1 in this case is a slope, no longer a partial sill. You may also set the range to a value larger than the maximum possible distance.
On 07/02/2013 04:16 PM, Tobias Vetter wrote:
Thank you. So as long as all my distances are smaller than the range I will not have this problem? Tobias
Tobias, try using another variogram model: the linear model with sill is not positive definite in more than one dimension (and yes: a warning about this would have been very nice!) On 07/02/2013 03:37 PM, Tobias Vetter wrote:
Dear all, I am interpolating automatically daily air temperature values using kriging with external drift (altitude) and the library gstat. From time to time (quite random) I get unrealistic predictions like -400?C with very high kriging weights like 2000. Looking at the data everything seems to be ok. Then I changed the variogram ranges a little bit and the problem disappears. How can this behavior be explained? I have attached a small example script for demonstration and some data. Thanks you Tobias
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