[gmx-users] xtc C programming

[Eviatar Tron]

Hi,
Ive been trying to write a trajectory file using the 
xtc functions, but even the most primitive program,
which is just
main()
{
  :
  int xfp=open_xtc("Traj.xtc","w");
  :
  :
  write_xtc(xfp,40,1,0.0,box,atoms,3.1);
  close_xtc(xfp);
  :
}
fails with a message:
Fatal error: Trying to access non-open file 1075115271, in gmxfio.c, line 848

the file descriptor assigned is 0, which seemd ok looking at xtcio.c
if anyone can help
	thanks
		Eviatar