Re: st: foreach for interaction term

[Maarten Buis <maartenlbuis@gmail.com>]

On Tue, May 24, 2011 at 4:21 PM, Barbara Engels <engels.ba@gmail.com> wrote:
> well, now i modified it again, to make it more understandable for me and for stata.
>
>  foreach `x' of ger_ims bel_ims chin_ims usa_ims uk_ims it_ims switz_ims {
>  2.   ge foreignbrd*=`X'*(*brd)
>  3.  }
> invalid syntax
> r(198);
>
> I want it to create values containing the product of import share and R&D stock (=foreignbrd) of each country for each year.
>
> Is that understandable? I 'm a little confused.

There are a great many things wrong here:

In your code -foreach- creates a local with a name stored in the local
x. This is (probably) wrong. Instead you would (probably) want to say
foreach x of ...

You need to specify what kind of list you specify when you say -of- in
-foreach-, alternatively you can say -in-.

You cannot interchange `x' with `X', the two are different things.

you cannot use wildcards this way, instead you probably want a nested loop

 foreach x of varlist ger_ims bel_ims chin_ims usa_ims uk_ims it_ims switz_ims {
    foreach y of varlist *brd {
        ge `x'_X_`y' =`x'*`y'
    }
}

-- Maarten

--------------------------
Maarten L. Buis
Institut fuer Soziologie
Universitaet Tuebingen
Wilhelmstrasse 36
72074 Tuebingen
Germany


http://www.maartenbuis.nl
--------------------------

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