P Chart

[Katelyn DeAlmeida]

Hi!

I would like to create a p chart that recalculates at a designated point. Attaching an image to illustrate. I realize this wasn't created by Stata, but feels like something Stata should be able to.

Thanks

[Andrew Musau]

There is a reference to 'CL,' which I assume stands for confidence limit. To calculate these limits, you need information about the distribution— in case you don’t have these a priori. Otherwise, to me, the graph appears to be a plot of the maximum, minimum, and mean over some range. You can use twoway to generate such a plot.

clear
*GENERATE DATASET ASSUMING SOME STRUCTURAL BREAK
set seed 03202025
set obs 41
gen series1 = rnormal(15, 3)
gen series2= rnormal(10, 3)
gen series= cond(_n<=24, series1, series2)
drop series?
gen which= cond(_n<=24, 1, 2)  
gen week=_n

*START HERE
frame put series which, into(new)
frame new: collapse (min) min= series (max) max=series (mean) mean=series, by(which)
frlink m:1 which, frame(new)
frget min max mean, from(new)
drop new
frame drop new
 
*GRAPH
tw scatter series week || ///
line max week, lp(dash) lc(red) || ///
line min week, lp(dash) lc(red) || ///
line mean week, lc(red) lp(.-.) || ///
line mean week if which==1 , lc(red) || ///
line mean week if which==2 , lc(red) leg(off) xlab(1(4)41)