ENH: use math instead of numpy in non vector operations

Author: MateusStano

rocketpy/rocket/aero_surface/fins/_geometry.py

@@ -338,7 +338,9 @@ def get_data(self, include_outputs=False):
             "AR": getattr(self, "AR", None),
             "gamma_c": getattr(self, "gamma_c", None),
             "Yma": getattr(self, "Yma", None),
-            "roll_geometrical_constant": getattr(self, "roll_geometrical_constant", None),
+            "roll_geometrical_constant": getattr(
+                self, "roll_geometrical_constant", None
+            ),
             "tau": getattr(self, "tau", None),
             "lift_interference_factor": getattr(self, "lift_interference_factor", None),
             "roll_damping_interference_factor": getattr(

rocketpy/rocket/aero_surface/fins/elliptical_fin.py

@@ -167,12 +167,7 @@ def __init__(
     def evaluate_center_of_pressure(self):
         """Calculates and returns the center of pressure of the fin in local
         coordinates. The center of pressure position is saved and stored as a
-        tuple.
-
-        Returns
-        -------
-        None
-        """
+        tuple."""
         # Barrowman elliptical-fin center of pressure location.
         cpz = 0.288 * self.root_chord
         self.cpx = 0

rocketpy/rocket/aero_surface/fins/fin.py

@@ -276,22 +276,26 @@ def evaluate_rotation_matrix(self):
         """
         phi = self.angular_position_rad
         delta = self.cant_angle_rad
+        sin_phi = math.sin(phi)
+        cos_phi = math.cos(phi)
+        sin_delta = math.sin(delta)
+        cos_delta = math.cos(delta)
 
         # Rotation about body Z by angular position
         R_phi = Matrix(
             [
-                [np.cos(phi), -np.sin(phi), 0],
-                [np.sin(phi), np.cos(phi), 0],
+                [cos_phi, -sin_phi, 0],
+                [sin_phi, cos_phi, 0],
                 [0, 0, 1],
             ]
         )
 
         # Cant rotation about body Y
         R_delta = Matrix(
             [
-                [np.cos(delta), 0, -np.sin(delta)],
+                [cos_delta, 0, -sin_delta],
                 [0, 1, 0],
-                [np.sin(delta), 0, np.cos(delta)],
+                [sin_delta, 0, cos_delta],
             ]
         )