From: Phil Schumm <pschumm@uchicago.edu>
Reply-To: statalist@hsphsun2.harvard.edu
To: statalist@hsphsun2.harvard.edu
Subject: Re: st: Generating a vector
Date: Sat, 20 May 2006 16:08:26 -0500
On May 20, 2006, at 1:07 AM, Gauri Khanna wrote:
I would like to generate an 1 x n vector, (n=326 rows) for cross
sectional data. This is actually an input price vector.
I would then want to fill it with three or four input prices that I have
computed elsewhere. Hence the same value for each of the inputs will be
repeated 326 times.
I don't understand; if the vector is 1 x 326, and if each value will be
repeated 326 times, then you'll need 4 separate vectors to hold the 4
values, no?
I guess the first step would be to generate an empty(?)/null vector and
then fill it with values for each of the inputs.
I'm sorry, but there's really not enough here to give much of an answer.
If you want to generate a matrix containing a constant value, then you
want to use the function J(), like so:
. mat a = J(1,5,23)
. mat li a
a[1,5]
c1 c2 c3 c4 c5
r1 23 23 23 23 23
Note that -help matrix- (followed by clicking on "matrix functions") would
have also given you this answer. So, the first "meta-answer" to your
question is really a suggestion that if you want to work with matrices in
Stata, you should spend some time with [P] matrix.
In addition, it looks as though your immediate question is just the first
step in what is really a larger problem you are trying to tackle. If this
is true, then it is really better to ask "I'm trying to do X and I think Y
is a good place to start, but I'm having problems" rather than just asking
"I can't figure out how to do Y". There are at least two reasons for
this. First, Y may not be the best way to start, so you should give
people on the list an opportunity to tell you that; after all, getting you
started on the right path is half the battle. Second, if you are having
problems with Y, there's a good chance you will also have problems with
subsequent steps, and it's a lot more efficient for everyone involved if
you just give your whole problem up front and let people help you with the
entire thing. Moreover, this makes for much more useful list archives
(i.e., those who come along later with the same problem will be able to
find the answer in a single posting or two, instead of spread across
many).
That said, your question suggests that you are working on a economic
problem, and not being an economist, I'm afraid others may need to help
you solve it (but I too will read their answers and learn). I apologize
to the economists on the list for having volunteered your services ;)
-- Phil
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