Why is my forvalues loop in stata not working?

Question

I am trying to find outliers in a variable called nbrs, generating an interquartile (iqr) range called nbrs_iqr. I then want to loop (for practice with this looping concept) the values 1.5, 2, 5, and 10 in to multiply them by the iqr.

I keep getting a syntax error (invalid syntax r(198);) on the loop. I have seen something about not being able to do the forvalues loop when the values are not a range but have seen examples where it is a non-range without being explicit that that is permitted. I figured the spaces worked to separate the non-range values but I've thrown up my hands from there.

sum nbrs, detail
return list
gen nbrs_iqr = r(p75)-r(p25)
tab nbrs_iqr

forvalues i = 1.5 2 5 10 {
    gen nbrs_out_`i'=`i'*nbrs_iqr
}

Answer 1

help forvalues is clear on the syntax you can use. Yours is not a valid range. You can work with foreach, but notice that a . in a variable name is not allowed.

One solution is to use strtoname():

clear
set more off

sysuse auto
keep price

sum price, detail 

gen nbrs_iqr = r(p75)-r(p25) 

foreach i of numlist 1.5 2 5 10 { 
    local newi = strtoname("`i'")
    gen nbrs_out`newi' = `i' * nbrs_iqr 
}

describe

My advice: familiarize yourself with help help.