pb with oct file, return a matrix

[John W. Eaton]

On 22-Apr-2009, Alain Baeckeroot wrote:

| I wrote a DEFUN_DLD and have trouble to return a matrix, it segfault
| at return retval or in main program M=boucle_cc(...)!
| I tried to run in gdb (and mkoctfile -g) but it does not help me.
| 
| I think i have exactly copied a working DEFUN_DLD i have which 
| returns a matrix, but ...
| 
| Any help/hint/url is welcome :-)
| Alain
| 
| ------------------------------------------------------
| Here is the code (with printf for debugging)
| DEFUN_DLD( boucle_cc, args, nargout, "usage : rMat = boucle_cc(..)\n") {
| 	int NDATA=10000;
| 	Matrix rMat(NDATA, 22);	// results
| 	octave_value_list retval;   // list of return values
| 
| 	...compute and put everything in rMat...
| 
| 		printf(" ici boucle_cc 7, avant retval(0)= rMat\n");
| 		printf(" rMat(0,0) = %lf, (9999,21) = %lf;\n", rMat(0,0), rMat(9999,21) );
| 	retval(0) = rMat;
| 		printf(" ici boucle_cc 8, avant return retval\n");
| 	return retval;
| }

Does it work if you simplify your function to be just the following:

  DEFUN_DLD( boucle_cc, args, nargout, "usage : rMat = boucle_cc(..)\n") {
	  int NDATA=10000;
	  Matrix rMat(NDATA, 22, 0.0);	// results
	  octave_value_list retval;   // list of return values
	  retval(0) = rMat;
	  return retval;
  }

?  If so, then I'd guess that you have some problem in the

| 	...compute and put everything in rMat...

part.  Given the error message you see, I'd guess that you are writing
outside the bounds of the rMat array.  But that's just a guess.

jwe