Re: st: creating unique identifier values

[Richard Williams <Richard.A.Williams.5@ND.edu>]

At 09:06 PM 3/8/2006, you wrote:
> No idea why you would want to do it, but it's easy with -forval-
>
> clear
>  set obs `=26*35'
>  g x=.
>  g a=.
>  g i=.
>  local n=1
> forv i=1/26 {
>     forv a=1/35 {
>      qui  replace x=`i'`a' in `n'
>      qui  replace i=`i'  in `n'
>      qui  replace a=`a' in `n'
>    local n=`n'+1
>   }
> }
Austin beat me to it.  My solution was

clear
set obs 910
gen id = 0
local casenum = 0
forval i = 1/26 {
        forval j = 1/35 {
                local casenum = `casenum' + 1
                if `j' < 10 {
                        quietly replace id = `i' * 10 + `j' in `casenum'
                }
                else {
                        quietly replace id  = `i' * 100 + `j' in `casenum'
                }
        }
}

BUT, are you sure you want to do it this way???  Note that you DO NOT 
get unique ids this way.  For example, 211 shows up twice - once with 
case 2, attribute 11, and again with case 21, attribute 1.  Where I 
have `i' * 10 above, I would make it `i' * 100 (The code could be 
simplified further, of course). i.e. make it 100* subject number + 
attribute number.


-------------------------------------------
Richard Williams, Notre Dame Dept of Sociology
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