--- On Wed, 18/2/09, Carlo Fezzi <[email protected]> wrote:
> I am trying to check what the code does and therefore look
> into the macro `u_k' to make sure it contains what I want.
> In this simple case I want it to contain "u1 u2 u3".
> So I am typing:
>
> -----
> clear
>
> scalar u1 = 1
> scalar u2 = 5
> scalar u3 = -1
>
> local u_k "u1"
>
> forvalues i = 2/3 {
> local u_k "`u_k' u`i'"
> display `u_k'
> }
>
> display `u_k'
> -----
>
> Why when I ask Stata to display the macro content inside
> the loop it works fine but when I ask it just after the
> loop, Stata does not return any value?
I am assuming you ran the forvalues loop from a .do file and
afterwards, interactively asked fo the display of `u_k'. The
thing about a local macro is that it is local, also local to
a run of a .do file. So, if you do your entire example in one
go you'll find that it does what you asked it to do.
As an aside: The aim of this loop is to create a string
containing the parts you want to feed to -args-. You can more
directly see the string using -display- if you surround the
local with quotes, like this:
*---------- begin example -----------
local u_k "u1"
forvalues i = 2/3 {
local u_k "`u_k' u`i'"
display "`u_k'"
}
display "`u_k'"
*---------- end example --------------
-- Maarten
-----------------------------------------
Maarten L. Buis
Department of Social Research Methodology
Vrije Universiteit Amsterdam
Boelelaan 1081
1081 HV Amsterdam
The Netherlands
visiting address:
Buitenveldertselaan 3 (Metropolitan), room N515
+31 20 5986715
http://home.fsw.vu.nl/m.buis/
-----------------------------------------
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