# st: Re: graph question

 From "Martin Weiss" To Subject st: Re: graph question Date Sun, 19 Apr 2009 19:35:36 +0200

```<>

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" <npandis@yahoo.com>
```To: <statalist@hsphsun2.harvard.edu>
Cc: <npandis@yahoo.com>
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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```
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