From help-octave-request at bevo dot che dot wisc dot edu Tue Apr 29 08:42:48 2003
Subject: Re: Replacement of struct_elt_ref
From: Laurent Mazet <laurent dot mazet at motorola dot com>
To: help-octave at bevo dot che dot wisc dot edu
Date: Tue, 29 Apr 2003 15:41:32 +0200

On Mon, 28 Apr 2003 22:39:33 -0400
Paul Kienzle <pkienzle at users dot sourceforge dot net> wrote:
> Laurent Mazet wrote:
> >Helo,
> >
> >I used to use struct_elt_ref method to extract data field from a structure in my C++ oct-file. Since 2.1.4x, this method disapears. Does anyone knows how to deal with structures in new version ?
...
> 
> It looks like you should be able to use
> 
>     octave_value map = args(0);
>     octave_value el = map.single_subsref 
> (".",octave_value_list(octave_value("field")));
> 

At least, I found an elegant way to do it:

/* OCTAVE_VERSION == 2.0.x */

  Matrix strans = args(3).struct_elt_ref("strans").matrix_value();

/* OCTAVE_VERSION <= 2.1.36 */

#include <octave/oct-lvalue.h>
 Matrix strans = args(3).struct_elt_ref("strans").value().matrix_value();

/* OCTAVE_VERSION > 2.1.36 */

#include <octave/oct-map.h>
  Octave_map map = args(3).map_value();
  Matrix strans = map["strans"](0).matrix_value();

I think this summary might help.

         Laurent
-- 
Dr. Laurent Mazet: Research Engineer /V\ Centre de Recherche de MOTOROLA
Tel: +33 (0)1 69 35 48 30 =-=-=-=-=-=-=-=-=-=-= Email: mazet at crm dot mot dot com



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