Richard Lenhardt wants to plot, with confidence intervals,
the proportion drug users for each month. To proceed I
created an artificial dataset with 30% users:
clear
set seed 12345
set obs 1000
gen x=0
replace x=1 if uniform()<0.3
gen month=1+int(12*uniform())
-ci x, binomial- calculates proportion and confidence limits
for each month. -ci- saves r(mean), r(lb) and r(ub), and
-statsby- lets you include these results in a new dataset (test1):
statsby "ci x, binomial" r(mean) r(lb) r(ub), by(month) saving(test1) replace
use test1 , clear
rename _stat_1 prop
rename _stat_2 lb
rename _stat_3 ub
twoway (line prop month)(rcap lb ub month)
Is that what you wanted.
Actually Nick Cox made -ciplot-, to be downloaded by:
ssc install ciplot
-ciplot- does much of the same, but the first method gives you
more freedom when designing the graph, I think.
Hope you can use this.
Svend
________________________________________________________
Svend Juul
Institut for Folkesundhed, Afdeling for Epidemiologi
(Institute of Public Health, Department of Epidemiology)
Vennelyst Boulevard 6
DK-8000 Aarhus C, Denmark
Phone, work: +45 8942 6090
Phone, home: +45 8693 7796
Fax: +45 8613 1580
E-mail: [email protected]
_________________________________________________________
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