Dear list
Last week I asked the following question regarding the gaussian
semivariogram model:
I have experienced that the gaussian semivariogram model sometimes lead
to a covariance matrix which is not positive definite. I am aware that
the parabolic behavior of the function near the origin
Hello,
Problems with the Gaussian semivariogram typically
arise when no nugget effect is specified and
some observations are very close to each other,
leading to covariances matrice with very similar rows.
You can read more about this pathological model in Hans
Wackernagel's book multivariate
