BUG: RailButtons does not have rocket_radius attribute #606.

rocket_radius attribute added to RailButtons Class

rocketpy/rocket/aero_surface.py

@@ -1861,7 +1861,8 @@ class RailButtons(AeroSurface):
         relative to one of the other principal axis.
     """
 
-    def __init__(self, buttons_distance, angular_position=45, name="Rail Buttons"):
+    def __init__(self, rocket_radius, buttons_distance,
+                 angular_position=45, name="Rail Buttons",):
         """Initializes RailButtons Class.
 
         Parameters
@@ -1874,6 +1875,8 @@ def __init__(self, buttons_distance, angular_position=45, name="Rail Buttons"):
             relative to one of the other principal axis.
         name : string, optional
             Name of the rail buttons. Default is "Rail Buttons".
+        rocket_radius: int, float, optional
+            The reference rocket radius used for lift coefficient normalization.
 
         Returns
         -------
@@ -1884,7 +1887,7 @@ def __init__(self, buttons_distance, angular_position=45, name="Rail Buttons"):
         self.buttons_distance = buttons_distance
         self.angular_position = angular_position
         self.name = name
-
+        self.rocket_radius = rocket_radius
         self.evaluate_lift_coefficient()
         self.evaluate_center_of_pressure()
 

rocketpy/rocket/rocket.py

@@ -1509,8 +1509,9 @@ def set_rail_buttons(
             RailButtons object created
         """
         buttons_distance = abs(upper_button_position - lower_button_position)
-        rail_buttons = RailButtons(
-            buttons_distance=buttons_distance, angular_position=angular_position
+        rail_buttons = RailButtons(rocket_radius=self.radius, 
+                                   buttons_distance=buttons_distance,
+                                   angular_position=angular_position
         )
         self.rail_buttons.add(rail_buttons, lower_button_position)
         return rail_buttons