Re: st: RE: Using Mata within a foreach loop = r(1)

[Pablo Mitnik <pmitnik@ssc.wisc.edu>]

This is rather inconvenient when you have a longer code to run in Mata; 
and I haven't found any explanation in the manuals why the code with 
"mata" and "end" shouldn't work -- my bet is that this is a bug. 
Anyway,  thanks Abdel and Nick for the workaround.
Pablo

Nick Cox wrote:

> Abdel was quite correct to leave out an -end- statement. His example 
> was a series of separate invocations of Mata. 
> Pablo Mitnik
>
> Thanks for your answer -- but observe you left the end statement out. I
> want to get out of Mata and continue doing stuff in the loop. When you
> add the end command, the error I described is generated.
> Pablo
>
> Abdel Rahmen El Lahga wrote:
>   
> > I don't understand your loop but the code below work 
> > *===================== foreach i in 1 2 {
> >  mata: A=1,2
> >  mata: A
> >  mata: mata clear
> >  }
> > *======================
> >     
>   
> > 2007/12/7, Nick Cox <n.j.cox@durham.ac.uk>:
> >   
> >     
> > > My guess is that you have to respect much more the fact that Stata 
> > > and Mata are different languages. I don't think you can mix them 
> > > quite like this.
> > >
> > > Something like
> > >
> > > foreach ... {
> > >         ...
> > >         myprog ...
> > >         ...
> > > }
> > >
> > > where -myprog- is a Stata program that calls Mata is more likely to 
> > > succeed.
> > >
> > > As your real problem is different, further advice may wait upon 
> > > details.
> > >
> > > Pablo Mitnik
> > >
> > > When I try to do stuff in Mata within a loop, in a do file, I receive
> > >       
>   
> > > the following error message:
> > >
> > > --Break--
> > > r(1);
> > >
> > > end of do-file
> > >
> > > --Break--
> > > r(1);
> > >
> > > I looked up r(1), and it says:
> > >
> > > [P]     error . . . . . . . . . . . . . . . . . . . . . . . . .
> > >       
> Return
>   
> > > code 1
> > >         You pressed Break.  This is not considered an error.
> > >
> > > (Of course, I don't press break while the loop is executing.)
> > >
> > > The following very simple loop reproduces the error I get
> > >
> > > foreach i in 1 2 {
> > > mata:
> > > A=1,2
> > > A
> > > mata clear
> > > end
> > > }
> > >
> > > Any clue about what my mistake is?
> > >       
> *
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>   
--
Pablo A. Mitnik
University of Wisconsin-Madison (http://www.wisc.edu/ )
Department of Sociology ( http://www.ssc.wisc.edu/soc/)
Center on Wisconsin Strategy (http://www.cows.org/ )
1180 Observatory Drive
Room 7114A
Madison, WI 53706
TEL (608) 2621839
E-mail: pmitnik@ssc.wisc.edu 

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