Re: st: programming assist, too many unique values for levels

["Michael Blasnik" <michael.blasnik@verizon.net>]

Nick Cox wrote:
<snip>
> 4. In fact, you can do it directly without loops.
> Michael might do it something like this.
> (Note that Andrew already sorted by -pt-.
>
> ------------------------------------- #4
> by pt : egen time = total(obstime)
> --------------------------------------
>
> 5. However, this is more efficient, as
> it avoids the interpretive overhead of -egen-
> (-viewsource egen.ado- and -viewsource _gtotal.ado-
> to see what I mean).
>
> ------------------------------------ #5
> by pt : gen time = sum(obstime)
> by pt : replace time = time[_N]
> ------------------------------------

Actually, I would use option 5 in my own do file, but I would recommend option 4 
to anyone else unless I knew they were working on a large dataset where speed 
may be an issue.

Michael Blasnik 
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