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