search for: ar1xar1

...large datasets / complex models possible (sometimes in nearly real-time). 'Amazing' is a word that comes to mind. (Side note: I have heard rumors that SAS has hired a developer to look at the Average Information REML technique...) SAMM can fit two-dimensional spatial structures (such as AR1xAR1) and can plot two-dimensional variograms. The 'engine' for the mixed-models in SAMM is the same one used by Genstat and ASREML. Like all mixed-models software, SAMM has quirks such as convergence issues, degrees of freedom, model-specification, etc. The user community is small, so resour...

...ating Try removing the variance component for Rep in: random=~1|Rep/WholePlot. Try changing an nested effect from random to fixed (or vice-versa). Try to extract lsmeans for fixed-effects in a model. Try to do a multiple-comparison of fixed-effects estimates. Try using AR1xAR1 error structure. The nlme library appears to have tools for this, but again is syntactically difficult. I can find no examples. Most of these tasks would ideally be straightforward in a general-purpose mixed-models function (as they are in SAS, Genstat, etc.) The ASR...