<>
With CIs :-)
***
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=rnormal()
}
//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
//graph
twoway (rcap lb ub interval, sort) (scatter mean interval), ///
xlabel(0 1 3 6 9 12) by(, legend(off)) by(arm, note(""))
****
HTH
Martin
_______________________
----- Original Message -----
From: "Nikolaos Pandis" <[email protected]>
To: <[email protected]>
Cc: <[email protected]>
Sent: Sunday, April 19, 2009 6:19 PM
Subject: st: graph question
Hi to all.
I would like to ask the following:
I have continuous data for two trial arms (control and experiment).
There are 50 measurements per arm.
Data is collected at 6 time intervals.
I would like to plot a bar chart with the x axis showing the intervals (0,
1, 3, 6, 9, 12 months). Within each interval I would like to have one bar
for the control and one for the experimental group.
The y axis shows the mean of the measurement of interest.
Additionally, I would like to show the confidence intervals at each
interval per treatment group.
Alternatively, I would like to draw a line plot with the same y and x
axis information, except that the two lines would represent the control
and the experimental groups.
Thank you very much,
Nick
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