Re: .oct: load matrix from file

[Paul Kienzle]

You can call load easily enough from an .oct function:

        octave_value_list args;
        args(0) = filename;
        args(1) = "P1";
        feval("load", args, 0); // no arguments returned
        if ( error_state )
           // unable to load variable

You can access the current symbol table easily enough as well,
though I don't know if this is the approved approach:

        octave_value P1;
        symbol_record *sr = curr_sym_tab->lookup("P1");
        if (sr == NULL || sr->def().is_undefined ())
           // unable to access variable (maybe global?)
        else
           P1 = sr->def ();

It is a shame you have to go through the symbol table all the time with
load.  It would be nice if it could return a structure of all the names
in the file instead.

Paul Kienzle
address@hidden

On Fri, Oct 20, 2000 at 04:01:37PM +0200, Andy Jacobson wrote:
> Howdy,
> 
>       I am a rank beginner at the .oct game, and I am having a
>       difficult time seeing the forest through the trees.  
> 
>       There is an operation I want to make on a sequence of n
>       matrices, P1, P2, ....Pn, all stored in a single .mat file.  I
>       would like to access these matrices from an .oct function, but
>       I can't quite grok the philosophy behind the source.  I had
>       hoped that the octave_value_list returned by an feval of
>       "load" would give the set of matrices in the file, but this is
>       not so; the returned list is empty (and the matrices are loaded
>       into the interpreter environment).
> 
>       I have pored over the source but can find no hint of a .cc
>       file doing such a thing.  Anybody have a pointer to
>       enlightening examples?
> 
>       Peace,
>               Andy
> 
> -- 
> address@hidden
> 
> 
> 
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