From help-octave-request at bevo dot che dot wisc dot edu Fri Feb  6 02:58:21 2004
Subject: RE: Question about how to use an existing octave function in a cc 	 code
From: THOMAS Paul Richard <prthomas at drfccad dot cea dot fr>
To: "'Wen-shiang Chen'" <chenwe at chemeng dot ohio-state dot edu>,    help-octave 	 <help-octave@bevo.che.wisc.edu>
Date: Fri, 6 Feb 2004 09:49:21 +0100 

Wen-shiang,

If your matrices are 2 by 10, I would seriously doubt that it is worth your
while writing a DLD.  However, if this is an in principle test, I suggest
that you peruse some of the examples of DLDs in the mailing lists that make
use of feval (with which you could call randn):

eg http://www.octave.org/mailing-lists/help-octave/2003/1809

is a good example because it illustrates not only the use of feval (which
you would use to call randn) but also checking of arguments of the DLD.

If you do not wish to suffer the performance loss that results from calling
the interpreter, you can call the octave library routines directly, using
your_octave/src/DLD-FUNCTIONS/rand.cc as the template, or, more simply, the
C library rand(), used with srand(seed) for initialisation.

Paul 

-----Message d'origine-----
De : Wen-shiang Chen [mailto:chenwe at chemeng dot ohio-state dot edu]
Envoyé : jeudi 5 février 2004 23:43
À : help-octave
Cc : CHENWE at chemeng dot ohio-state dot edu
Objet : Question about how to use an existing octave function in a cc
code


Sorry to ask such a newbie question!  I have very limited knowledge about
c++ programming and just start to learn how to program under octave.

My question is how to use existing octave functions, in this case, the
randn function, in my cc code?  The m-file looks like the following,
x=y+randn(2,10);
and my incomplete cc code looks like the follwing,
DEFUN_DLD (mycc, args, ,)
{
  Matrix x (2,10);
  Matrix y (2,10);

  x=y+??
}

So could someone shed some light for me on how to write
 x=y+randn(2,10);
in my cc code?  Thanks!

Wen-shiang Chen



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