*! Marc Jacobs, Utrecht, maandag 6 januari (1) 1992, <15:19>
* REVERSE RECODING 
* syntax: omscore var_name
* new variabele will be created: rr_var_name
* algoritm: (max+min) - score
* only possible if: increment = 1, adjecent values of variabele 
* testing by correlating original and reverse recoded variabele. 
* Correlation must be -1

prog def omscore
version 2.1
   if "%_*"=="" {
      di in red "SYNTAX: After" in wh " omscore " in red "is required: var_name for reverse recoding"
      exit 198
   }

capture macro drop %_m
capture macro drop %_i
capture drop rr_%_1

	capture g rr_%_1 = %_1
	confirm existence rr_%_1
	if _rc ~= 0 {
           di in red "SYNTAX: Shorten variable name " in ye "%_1" in red " to first 5 characters"
	    exit 198
	}
	quietly sum %_1
	mac def _m = _result(6) + _result(5)
	quietly replace rr_%_1 = %_m - %_1
	quietly corr %_1 rr_%_1
	mac def _i = _result(4)

	if %_i ~= -1 {
	di in red "Reverse recoding went wrong... new variabele " rr_%_1 " deleted"
	di in red "Possible problems: increment not 1 or values variabele not joined"
	drop rr_%_1
	}

	if %_i == -1 {
	di in bl "Reverse recoding ok. New variabele = rr_%_1"
	} 

capture macro drop %_m
capture macro drop %_i
end