--- On Mon, 16/3/09, Justin B Echouffo Tcheugui wrote:
> I tried the command stcox with the option -shared () as
> you advised. As you can see below I am not having the
> desired output:
> could not calculate numerical derivatives flat or
> discontinuous region encountered r (430)
One posibility that jumps to mind is: are there any
clinics that only have (valid) observations on either
the treatment or the controll group?
So type:
tab randomgroup clinic, if !missing(_t)
and see if any of the reported counts equal zero.
-- Maarten
-----------------------------------------
Maarten L. Buis
Institut fuer Soziologie
Universitaet Tuebingen
Wilhelmstrasse 36
72074 Tuebingen
Germany
http://home.fsw.vu.nl/m.buis/
-----------------------------------------
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