Title graphs with alphabet letters in a loop

[Davide Bellucci]

Dear all,

I am trying to produce a set of 16 graphs in a loop, giving them as title alphabet letters in sequential order.

My task is as follows:

I have a dataset with 2 independent variables (X1 and X2) and 2 dependent variables (Y1 and Y2). I am running regressions in a loop for each independent variable over each dependent variable using the permute command with 1000 repetitions.
I then save the distribution of the coefficients obtained through the permutation in a dataset, as I want to use the distribution to make kdensity graphs. What I obtain in the end are 4 datasets, each one containing one distribution of the coefficient, and 4 graphs, one for each distribution.

However I am not finding a way to title these graphs with alphabet letters in sequential order. That is, I want the first graph to be titled "A", the second graph to be titled "B", the third "C" and the fourth "D".

Here is the code that I am trying to complete.

foreach exp in X1 X2 {
foreach dep in Y1 Y2 {

permute `exp' _b[ `exp' ], saving( `exp'_`dep' ) reps(1000): reg `dep' `exp'

preserve

use `exp'_`dep' , clear

twoway kdensity _pm_1, graphregion(color(white)) ytitle("Density") xtitle("") title()

graph save "`exp'_`dep'.gph", replace

restore

}
}

Hope I have been clear in describing my issue and that somebody here have hints for a solution.

Thanks, Davide

[Maarten Buis]

Silly example that works as long as you have less than 26 graphs:

local i = 1
foreach exp in X1 X2 {
    foreach dep in Y1 Y2 {
        local letter `: word `i++' of `c(ALPHA)''
        twoway function y=x, title(`letter')
    }
}

[Nick Cox]

Type

creturn list

and especially look at the end of the results. People are often surprised to see several useful things.

[Davide Bellucci]

Your suggestions proved perfect. I have been able to reconstruct the code in both ways.
Thank you very much Maarten Buis and Nick Cox !