relativistic gamma/beta edit

ess/TraceWin.py

@@ -223,6 +223,8 @@ class plt:
             Eavg=self.avg['E'][j]
             self.gamma.append((self.mc2+Eavg)/self.mc2)
             self.beta.append(numpy.sqrt(1.-1./self.gamma[-1]**2))
+        self.gamma=numpy.array(self.gamma)
+        self.beta=numpy.array(self.beta)
 
     def calc_avg(self):
         '''