remove the unnecessary lines

bike/simu_bike.py

 import bike.gen as g
 import numpy as np
-import sys
-
-
-# initial, set up the physical world
-# the positions of points are generated using random function from np
-num_point = 4
-#points_position = np.random.rand(num_point, 2)*8+3
 
 # for test
 def creat_bike(points_position):
@@ -15,6 +8,7 @@ def creat_bike(points_position):
     Args:
         points_position (np.array): a 4x2 np.array
     """
+    num_point=len(points_position)
     start_x = np.max(points_position[:, 0])
     points_velocity = np.zeros_like(points_position)
 
@@ -33,15 +27,10 @@ def creat_bike(points_position):
     gravity = -9.81  # unit [ m /s2]
     spring_initial_length = g.calc_spring_length(points_position, spring_indexs)
 
-    # for animation
-    run_time = 15  # unit [s]
-    dt = 0.01     # unit [s]
-
     def update(points_position,points_velocity):
         # boundary condition 1
         if np.min(points_position[2:, 1] - g.ground(points_position[2:, 0])) < 0:
             return(np.max(points_position[:, 0])-start_x)
-            sys.exit(0)
         else:
             state_y = points_position[:, 1] - g.ground(points_position[:, 0])
             state_y[0] -= wheel_radius
@@ -64,6 +53,10 @@ def creat_bike(points_position):
             if points_position[0, 1] < wheel_radius+g.ground(points_position[0, 0]):
                 points_velocity[0, 0] = 2
 
+    # for time-domain solver
+    run_time = 15  # unit [s]
+    dt = 0.01     # unit [s]
+    
     for i in np.arange(1, int(run_time/dt)):
         update(points_position,points_velocity)
     return (np.max(points_position[:, 0])-start_x)