added liou_params to keyword args to pass params to liouville class

classical/chebyshev.py

@@ -9,7 +9,7 @@ class Chebyshev(Propagator):
     """ Chebyshev propagator for classical particle dynamics """
     name = 'chebyshev'
     def __init__(self, delta=1.0, lambda_min=None, nterms=None, signed=False,
-                 liouville=LiouvillePowersQP, **kwargs):
+                 liouville=LiouvillePowersQP, liou_params={}, **kwargs):
         Propagator.__init__(self, **kwargs)
 
         self.delta = delta
@@ -36,7 +36,8 @@ class Chebyshev(Propagator):
             self.cheb_coef[1:] = self.cheb_coef[1:]*2.
 
         self.iln = liouville(self.nterms, self.syst, scale=self.scale,
-                             shift=self.shift, recursion='chebyshev', sign=sign)
+                             shift=self.shift, recursion='chebyshev',
+                             sign=sign, **liou_params)
 
     def step(self, time, q, p):
         """ perform a time step with initial coordinate and momentum """