--- On Mon, 20/4/09, Martin Weiss wrote:
> Let me think about combining those two w/o overlapping...
What about this:
*---------------- begin example ---------------------
clear*
qui{
//create data
set obs 600
gen arm= cond(_n<301,0,1)
lab def arms 0 "control" 1 "experimental"
la val arm arms
egen float interval = fill(0 1 3 6 9 12 0 1 3 6 9 12)
egen float measurement = seq(), from(1) to(50) block(6)
//fictional value of measurement (no systematic diff btw control and experimental group)
gen mymeasurement=rchi2(3)
}
//check
mean mymeasurement, over(arm interval)
//collapse
collapse (mean) mean=mymeasurement (semean) semean=mymeasurement, by(arm interval)
gen lb= mean-invnormal(0.975)*semean
gen ub= mean+invnormal(0.975)*semean
gen interval2 = cond(arm == 1, interval + .25, interval - .25)
twoway bar mean interval2, barwidth(.4) || ///
rcap lb ub interval2, ///
xlabel(0 1 3 6 9 12) ///
xmlabel( -.25 "c" .25 "e" ///
.75 "c" 1.25 "e" ///
2.75 "c" 3.25 "e" ///
5.75 "c" 6.25 "e" ///
8.75 "c" 9.25 "e" ///
11.75 "c" 12.25 "e" ) ///
legend(off)
*------------------- end example -------------------
Hope this helps,
Maarten
-----------------------------------------
Maarten L. Buis
Institut fuer Soziologie
Universitaet Tuebingen
Wilhelmstrasse 36
72074 Tuebingen
Germany
http://home.fsw.vu.nl/m.buis/
-----------------------------------------
*
* For searches and help try:
* http://www.stata.com/help.cgi?search
* http://www.stata.com/support/statalist/faq
* http://www.ats.ucla.edu/stat/stata/
