Dear Sibylle, I suspect your residuals will never become normal, because your data are counts. Luckily, normality is not a requirement for variogramMessage 1 of 2 , Apr 9, 2002View SourceDear Sibylle,
I suspect your residuals will never become normal, because your data
are counts. Luckily, normality is not a requirement for variogram
calculation nor for kriging interpolation.
However, before calculating variograms it may be a good idea to
correct for non-stationarity in the variances, and work with Pearson
Gotway, C.A., Stroup, W.W. (1997) A Generalized Linear Model Approach
to Spatial Data Analysis and Prediction. Journal of Agricultural, Biological
and Environmental Statistics 2(2), pp. 157--178.
Diggle, P.J., Liang, K-Y., Zeger, S.L. (1994) Analysis of Longitudinal
Data. Oxford University Press, Oxford.
or the more advanced approach of:
Diggle, P.J., J.A. Tawn, R.A. Moyeed (1998), Model-based
geostatistics. Applied Statistics 47(3), pp 299-350.
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