# Modifying PALP settings

I encounter an error from PALP when I try to create a dual cone. I create a cone Cstar as an intersection of several other cones, then try to create its dual:

```
Cstar.dual();
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "_sage_input_25.py", line 10, in <module>
exec compile(u'open("___code___.py","w").write("# -*- coding: utf-8 -*-\\n" + _support_.preparse_worksheet_cell(base64.b64decode("Q3N0YXIuZHVhbCgp"),globals())+"\\n"); execfile(os.path.abspath("___code___.py"))
File "", line 1, in <module>
File "/tmp/tmpFOwj4h/___code___.py", line 2, in <module>
exec compile(u'Cstar.dual()
File "", line 1, in <module>
File "/opt/sage47/local/lib/python2.6/site-packages/sage/geometry/cone.py", line 1608, in dual
rays = list(self.facet_normals())
File "/opt/sage47/local/lib/python2.6/site-packages/sage/geometry/cone.py", line 2123, in facet_normals
for i in range(P.nfacets()):
File "/opt/sage47/local/lib/python2.6/site-packages/sage/geometry/lattice_polytope.py", line 2196, in nfacets
if self.is_reflexive():
File "/opt/sage47/local/lib/python2.6/site-packages/sage/geometry/lattice_polytope.py", line 1930, in is_reflexive
self._read_equations(self.poly_x("e"))
File "/opt/sage47/local/lib/python2.6/site-packages/sage/geometry/lattice_polytope.py", line 2712, in poly_x
return self._palp("poly.x -f" + keys, reduce_dimension)
File "/opt/sage47/local/lib/python2.6/site-packages/sage/geometry/lattice_polytope.py", line 1026, in _palp
self, self.vertices(), result)
ValueError: Error executing "poly.x -fe" for the given polytope!
Polytope: A lattice polytope: 10-dimensional, 47 vertices.
Vertices:
...[a large matrix]
Output:
increase POLY_Dmax!
```

How do I increase POLY_Dmax?

Can you post the Sage code you used to produce the error?

Edited to include the code.