From help-octave-request at bevo dot che dot wisc dot edu  Mon Jun  8 06:47:51 1998
Subject: Re: octave libs and builtin functions
From: "Erich Schneider" <eschneider at nefo dot med dot uni-muenchen dot de>
To: "help-octave at bevo dot che dot wisc dot edu" <help-octave@bevo.che.wisc.edu>
Date: Mon, 08 Jun 98 13:45:13 

On Thu, 4 Jun 1998 10:21:05 -0500 (CDT), John W. Eaton wrote:

>On 27-May-1998, Erich Schneider <eschneider at nefo dot med dot uni-muenchen dot de> wrote:
>
>| I'm already using the octave classes in my own C++ applications.
>| However, I don't quite understand how to use octave's builtin functions
>| like load, save or plot. I have problems in understanding what the
>| DEFUN_TEXT macros are doing. I cannot see that the functions defined by
>| these macros are exported. Does anybody have an example for using
>| octave builtin functions or saving, loading and plotting octave
>| variables in the mat format?
>
>The DEFUN macros provide the function declarations and enforce a
>uniform naming scheme for built in and dynamically loaded functions.
>  ...
>If you create the argument list yourself, you can call the function
>Ffoo:
>
>  octave_value_list args;
>
>  args(2) = ...
>  args(1) = ...
>  args(0) = ...
>
>  octave_value_list retval = Ffoo (args, nargout);

Thank you very much for the answer. I've done that with the save
function: Fsave( args, nargout ). However, the linker cannot resolve
the reference Fsave, since the shared libs don't seem to export these
functions.

>However, the functions defined by the DEFUN macros are really only
>intended to be called from functions that are running inside of
>Octave.  They are not particularly useful (and some would not even
>make sense) in standalone C++ programs.

Loading and saving e.g. mat files makes sense in a data aquisition
program which uses the Matrix classes for simple transformations and
storing the data. Plotting a matrix  makes sense if there is a need for
controlling the results of  an experiment. Doing this from a C++
application would be very comfortable. The analysis is of course better
done in octave.

I still don't understand how octave uses a builtin function like
Fsave() if these functions are not exported. They are not contained in
an imp file I generate from the shared libs. I would really appreciate
some help on this matter.

Thank you very much,
Erich Schneider


----------------------------------------------------------------------
Erich Schneider, Dipl.-Phys.     | eschneider at nefo dot med dot uni-muenchen dot de
Neurologische Forschung          | u7x31ay at lrz-muenchen dot de
Ludwig-Maximilians-Universit"at  | 
Klinikum Grosshadern, M"unchen   | Fax: +49,89,70906,101