*! version SWS3/stb-2:gr3/stb-12:gr3.1  gr3 utility
program define _3dmnmx 
	version 2.1
	quietly { 
		sum %_1
		mac def _diff = _result(6) - _result(5)
		if %_diff==0 { mac def _diff 1 } 
		gen _NEW=(%_1-_result(5))/(%_diff)
		mac def %_2`ZERO=-(_result(5)/(%_diff))
		drop %_1
		rename _NEW %_1
	}
end
exit
/*
	_3dmnmx varname key
		rescales varname to have range [0,1].  

		creates a macro named keyZERO that contains the value of the 
		rescaling corresponding to zero.

	Note:
		varname is recreated rather than replaced.  If varname was
		stored as an int and we simply replaced, we would end up 
		with all zeros and a single 1.  This way, we get what we want.
*/