Re: passing global variables when embedding octave

[Jaroslav Hajek]

On Mon, Mar 2, 2009 at 9:01 AM, Soeren Sonnenburg <address@hidden> wrote:
> Dear all,
>
> I've written a script to call python functions from within octave that
> passes variables to python and results back to octave (avoiding disk
> io). To this end I embedded python within octave context. (*)
>
> Now I would like to do the same for python, i.e. run a octave function
> from within python and pass all the variables to octave. So I need to
> embed the octave interpreter. The octave_embed example (from
> octave_embed.tar.gz ) shows how to run a script but not how to implant
> global variables/access variables in either direction.
>
> Could someone give an insight on how I can push a global variable to
> octave and also get the variable back?
>
> would be enough to show how
> octave_value x = octave_scalar(42);
>
> is made visible in octave context and incremented +1 and result
> transferred back...
>
> Thanks a lot!
> Soeren
>

symbol_table::global_varref (const std::string&) will create a
variable (or reference an existing one) in the global scope.
symbol_table::varref will work with local scope. Symbol table needs to
be initialized.
For more fine tuning, use symbol_table::insert which will return a
symbol_record&.


> (*) This will be in the shogun toolbox (http://www.shogun-toolbox.org),
> currently things like
>
> A=[[1,2,3];[4,5,6]];
> B=[[1,1,1];[0,0,0]];
> pythoncode=sprintf('import numpy\nresults=(A+B, 2*B, [ "bla1", "bla2" ])\n');
> [A2,B2,bla]=elwms('run_python', 'A',A, 'B',B, 'pythoncode', pythoncode)
>
> work.

Just out of curiosity; if Shogun is implemented in C++ (as the site
says), why do you want to interface Octave to Python for it?

Is the license compatible with GPL 3?

regards

-- 
RNDr. Jaroslav Hajek
computing expert
Aeronautical Research and Test Institute (VZLU)
Prague, Czech Republic
url: www.highegg.matfyz.cz