Hi 

Is there any option to create grand mean centering of a varibale x_mc,  (x_i - x_bar), group mean (x_barj), centering within clustered variable x_cwc (x_i - x_barj). These are necesary functions to teach mixed models. If there are not, i request you to provide.

The aggregate() function is probably your best friend here:

<hansl>
open mroz87.gdt 
matrix m = aggregate(WA, KL6, mean)
series grpmeans = replace(KL6, m[,1], m[,3])
series WA_demeaned = WA - grpmeans
boxplot WAdemeaned KL6 --fact --output=display
</hansl>

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  Riccardo (Jack) Lucchetti
  Dipartimento di Scienze Economiche e Sociali (DiSES)

  Università Politecnica delle Marche
  (formerly known as Università di Ancona)

  r.lucchetti@univpm.it
  http://www2.econ.univpm.it/servizi/hpp/lucchetti
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