[Nauty] Calling nauty()

[Wahid Chrabakh]

Hi:
	I want to use the nauty function to get the canonical form of a graph.
	I tried setting the proper options so that I can call the function
	with lab and ptn arguments set to NULL. This results in a segmentation
	fault. This is the code I use:
	static DEFAULTOPTIONS(options);
	options.writeautoms = FALSE;
	options.writemarkers = FALSE;
  options.getcanon = TRUE;
	options.defaultptn = TRUE;
	options.digraph = FALSE;
	nauty(g,NULL,NULL,NILSET,orbits,&options,&stats,workspace,160*NMAX,m,n,canong);

	The manual specifies that if defaultptn=TRUE then arguments 2 and 3
	are ignored, thus they can be set to NULL.
	
	I am only interested in canong. I would like to know what the minimal set of 
arguments I need to specify to get canong?
	Do I have to specify orbits, stats and workplace or is there a way to
	set some of them to NULL?

	thanks,
	Wahid.