Dear All, I found the following code
Code:
sysuse auto, clear
regress price c.length##c.mpg 
est store regression   

foreach v of var length mpg {
  sum `v' if e(sample)
  local low_`v' = r(mean)-r(sd)
  local high_`v' = r(mean)+r(sd)
}

margins, at(mpg=(`low_mpg' `high_mpg') length=(`low_length' `high_length')) 
marginsplot, xlabel(13 " " `low_mpg' "Low IV" `high_mpg' "High IV" 30 " ") ///
   ytitle("Price") ylabel(2000(1000)9000, angle(0) nogrid) ///
   legend(position(3) col(1) stack) title("") noci
with graphArray

My question is:
  1. How can I change the colors of lines?
  2. How can I obtain, say, a dash and/or dot line?
  3. Instead of circle, how can I obtain, say square symbol? Thanks in advance!