Re: st: Selecting part of a LARGE file

[David Kantor <dkantor@jhu.edu>]

At 10:47 AM 6/6/2003 -0500, Glenn Hoetker wrote:
> Hi all.
>
> I have two files.  File A has about 5000 unique values of the variable
> PATENT, which is 7 characters long.  File B has 16 million observations
> and several million unique values for PATENT.
> [...]
> I attempted using vallist.ado in File A to generate a long local macro
> (say, _useme) and then doing
>
>         use FileB if index(patent, "'useme'")
>
> I get 0 observations in this case (even though I know there are some
> matches).  From the manual, it appears that index is limited to strings
> of 80 characters, anyway.
I agree with Michael Blasnik, that a -merge, nokeep- should work, and the 
-nokeep- is essential to making this manageable.

Putting that aside, and putting aside the 80-character limitation, the 
reason that
  use FileB if index(patent, "'useme'")
gets no matches at all (when you do expect some) is that it should be...
  use FileB if index("'useme'", patent)

-- the arguments are reversed.

Nick Cox replied that you should expect no matches; he didn't say why.


David Kantor
Institute for Policy Studies
Johns Hopkins University
dkantor@jhu.edu
410-516-5404

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