program define maprange
	version 15.1
	syntax varname(numeric) [if] [in], ///
		from(numlist min=2 max=2) to(numlist min=2 max=2) ///
		GENerate(name) [REPLACE]
	tempname a b c d h
	sca `a'=`:word 1 of `from''
	sca `b'=`:word 2 of `from''
	sca `c'=`:word 1 of `to''
	sca `d'=`:word 2 of `to''
	sca `h'=(`d'-`c')/(`b'-`a')
	cap confirm variable `generate'
	if "`replace'"=="replace" & !_rc {
		qui replace `generate'=(`varlist'-`a')*`h'+`c' `if' `in'
	}
	else {
		if "`replace'"=="replace" {
			di in gr `"(note: variable `generate' not found)"'
		}
		qui gen `generate'=(`varlist'-`a')*`h'+`c' `if' `in'
	}
end