Fixed SegmentModel arguments

segmentmodel.py

@@ -880,8 +880,6 @@ class StrandInSegment(Group):
     def get_contour_points(self):
         c0,c1 = [self.segment.nt_pos_to_contour(p) for p in (self.start,self.end)]
         return np.linspace(c0,c1,self.num_nts)
-
-
             
 class Strand(Group):
     """ Class that holds atomic model, maps to segments """
@@ -982,7 +980,7 @@ class Strand(Group):
                 nt.orientation = orientation.dot(default_orientation) # this one should be correct
 
 class SegmentModel(ArbdModel):
-    def __init__(self, segments=[], local_twist=True,
+    def __init__(self, segments=[], local_twist=True, escapable_twist=True,
                  max_basepairs_per_bead=7,
                  max_nucleotides_per_bead=4,
                  dimensions=(1000,1000,1000), temperature=291,
@@ -1002,7 +1000,7 @@ class SegmentModel(ArbdModel):
 
         self._bonded_potential = dict() # cache bonded potentials
 
-        self._generate_bead_model( max_basepairs_per_bead, max_nucleotides_per_bead, local_twist)
+        self._generate_bead_model( max_basepairs_per_bead, max_nucleotides_per_bead, local_twist, escapable_twist)
 
         self.useNonbondedScheme( nbDnaScheme )