Margins plot using 25th and 75th quantile interaction

[Shuai Yan]

Hello,

I would like to find the continuous variables interaction plot using -margins- and -marginsplot- command.

(p25) specifies the 25th quantile observation of a variable. (p75) specifies the 75th quantile observation of a variable.

Should I do something like
margins, at(X=((p25) (p75)) Y=((p25) (p75)))

What I did is just find the p25 and p75 value of X, Y variable respectively. And put them in the margins, at(X = (0.25 0.75) Y=(0.25 0.75))
Do I do it right? Is there any other way to do this?

[Maarten Buis]

Here is how I would do this:

sysuse nlsw88, clear
logit union c.wage##c.hours i.south i.race
_pctile wage if e(sample), perc(10 25 50 75 90)
local w10 = r(r1)
local w25 = r(r2)
local w50 = r(r3)
local w75 = r(r4)
local w90 = r(r5)

margins , at(wage=(`w10' `w25' `w50' `w75' `w90') hours=(1/80) south=0 race=1)
marginsplot, xdim(hours) noci

You might also be interested in http://www.maartenbuis.nl/wp/inter_q...ter_quadr.html