Looping over variables

[Dee Laporte]

Hi there,

I'm trying to generate prevalence variable based on the calculation of two variables in the dataset.

How would I condense the following into a loop (I want to create separate variables for the years 2007 to 2018):

gen lsoapsyprev_2007 = (lsoapsych_2007/ LSOAmye_pop2007)*100
gen lsoapsyprev_2008 = (lsoapsych_2008/ LSOAmye_pop2008)*100
gen lsoapsyprev_2009 = (lsoapsych_2009/ LSOAmye_pop2009)*100

Many thanks

[Demetrio Guzzardi]

This should work

foreach n in 2007 2008 2009 {
gen lsoapsyprev_`n' = (lsoapsych_`n'/ LSOAmye_pop`n')*100
}

EDIT.
Just read that you want to do it till 2018. Then you could do

foreach n of numlist 2007/2018 {
gen lsoapsyprev_`n' = (lsoapsych_`n'/ LSOAmye_pop`n')*100
}

[Dee Laporte]

Thank you so much!

[Nick Cox]

I'll add the usual comment here that you have what in Stata circles is called a wide layout (structure, format). For almost all purposes you would be better off working long.

Another way to put this: You start out with 24 variables, and you're adding 12 more. Come a similar problem, 12 more. And so on. Also, given data for various years you should be wanting, at some point, graphs against year or some kind of time series analysis.. How are you going to do with your present layout?