more resilient secondary cone

star_origin doesn't always seem to be 0 if not 4d

cytools/triangulation.py

@@ -1618,9 +1618,10 @@ def secondary_cone(self,
 
  if self.is_star():
  # star triangulations all share 0th point, the origin
- simps = [set(s) for s in self._simplices[:,1:]]
+ star_origin = self.points_to_indices([0]*self.dim())
+ simps = [set(s)-{star_origin} for s in self._simplices]
  dim = self.dim()-1
- m[:,-1] = pts_ext[0]
+ m[:,-1] = pts_ext[star_origin]
  else:
  simps = [set(s) for s in self._simplices]
  dim = self.dim()
@@ -1656,14 +1657,14 @@ def secondary_cone(self,
  for i,pt in enumerate(diff_pts): full_v[pt] = v[i]
  for i,pt in enumerate(comm_pts): full_v[pt] = v[i+2]
  if self.is_star():
- full_v[0] = v[-1]
+ full_v[star_origin] = v[-1]
 
  null_vecs.add(tuple(full_v))
 
  for i,pt in enumerate(diff_pts): full_v[pt] = 0
  for i,pt in enumerate(comm_pts): full_v[pt] = 0
  if self.is_star():
- full_v[0] = v[-1]
+ full_v[star_origin] = v[-1]
 
  self._secondary_cone[args_id] = Cone(hyperplanes=list(null_vecs),\
  check=False)