Creating box plot for 13 variables

[Samita Giri]

Hi
I work with the prescription registry data. I have 13 drugs, and each drug is used in 4 different follow-up periods. I have to describe my data using a box plot that illustrates data for 13 drugs with 4 follow-up periods for each drug. My data looks as follow,

foreach x in a b c d e f g h i j k l m {
`x'_bl_pl90 `x'_pl91_pl180 `x'_pl181_pl270 `x'_pl271_pl365
}

In this example, a b c d e f g h i j k l m are the 13 drugs
`x'_bl_pl90 is the data for x drug during follow-up from baseline to 90 days
`x'_pl91_pl180 is the data for x drug during follow-up from 91-180 days
`x'_pl181_pl270 is the data for x drug during follow-up from 181-270 days
`x'_pl271_pl365 is the data for x drug during follow-up from 271-365 days

[Nick Cox]

So you really have 52 variables to plot? That is possible, but the result will be very crowded. Also, at least with graph box, it will be a struggle to see which box belongs to which variable.

clear 
set obs 100 

forval j = 1/52 {
    gen x`j' = rnormal(0, 1)
}

graph box x*

[Samita Giri]

Thank you Nick, could you please explain what ' j ', normal (0,1) takes in the value? My data are ratios for the variables that I mentioned above.

[Nick Cox]

That is just some code faking 52 variables to show for anyone curious what 52 box plots look like.

I created them using a loop. You can learn more about such loops from (e.g.)

help forvalues

or

SJ-21-2 pr0074_1  . . . . . .  Erratum: Speaking Stata: Loops, again and again
        . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N. J. Cox
        Q2/21   SJ 21(2):555                                     (no commands)
        erratum for a line of code

SJ-20-4 pr0074  . . . . . . . . . . . . Speaking Stata: Loops, again and again
        . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  N. J. Cox
        Q4/20   SJ 20(4):999--1015                               (no commands)
        provides updated guidance on using foreach and forvalues for
        looping through lists of values and repeating commands using
        members of those lists in turn

Clearly I don't have your data, and conversely the code is not needed by you because you do.

[Samita Giri]

Great !!, Thank you