[Gretl-devel] Re: [Gretl-users] error with null list

[Allin Cottrell]

On Fri, 5 Jan 2007, Sven Schreiber wrote:

>>> I do see "include" as problematic (since that's designed for importing
>>> function definitions), but "run" is not so bad.  In current CVS you can
>>> invoke "run" inside functions (though this is not much tested).
>
> This works like a charm for me! Tested with 'matrix' and 'print' 
> commands in the file which is run. Very cool, now everything 
> fits together!

Glad to hear it!

> Of course this immediately leads to new questions: Is it 
> possible to return more than one matrix from the function? I 
> tried to adapt section 10.2 of the user guide, but only got 
> error messages.

You can do this, but the "extra" returns have to be indirect.  You 
need to update your copy of the user guide!

http://ricardo.ecn.wfu.edu/pub/gretl/manual/PDF/

(Though there should be a way of doing this via the GUI.)

Trivial example:

function matfun (matrix *B, matrix *C)
   matrix A = mnormal(2,2)
   matrix B = mnormal(2,2)
   matrix C = mnormal(2,2)
   return matrix A
end function

nulldata 10

matrix B
matrix C
matrix A = matfun(&B, &C)
print A B C

Allin.