change the default option for CircularResistiveWall to exact=True from exact=False

mbtrack2/impedance/resistive_wall.py

@@ -87,7 +87,7 @@ class CircularResistiveWall(WakeField):
                  length,
                  rho,
                  radius,
-                 exact=False):
+                 exact=True):
         super().__init__()
 
         self.length = length
@@ -125,7 +125,7 @@ class CircularResistiveWall(WakeField):
         super().append_to_model(Wxdip)
         super().append_to_model(Wydip)
 
-    def LongitudinalWakeFunction(self, time, exact=False):
+    def LongitudinalWakeFunction(self, time, exact=True):
         """
         Compute the longitudinal wake function of a circular resistive wall 
         using Eq. (11), of [1], or approxmiated expression Eq. (24), of [2].
@@ -183,7 +183,7 @@ class CircularResistiveWall(WakeField):
             wl[idx2] = self.__LongWakeApprox(time[idx2])
         return wl
 
-    def TransverseWakeFunction(self, time, exact=False):
+    def TransverseWakeFunction(self, time, exact=True):
         """
         Compute the transverse wake function of a circular resistive wall 
         using Eq. (11), of [1], or approxmiated expression Eq. (26), of [2].