fewer magic numbers

donkey_gym/envs/donkey_env.py

@@ -25,7 +25,12 @@ class DonkeyEnv(gym.Env):
         "render.modes": ["human", "rgb_array"],
     }
 
-    ACTION = ["steer", "throttle"]
+    ACTION_NAMES = ["steer", "throttle"]
+    STEER_LIMIT_LEFT = -1.0
+    STEER_LIMIT_RIGHT = 1.0
+    THROTTLE_MIN = 0.0
+    THROTTLE_MAX = 5.0
+    VAL_PER_PIXEL = 255
 
     def __init__(self, level, time_step=0.05, frame_skip=2):
 
@@ -67,10 +72,11 @@ def __init__(self, level, time_step=0.05, frame_skip=2):
         self.viewer = DonkeyUnitySimContoller(level=level, time_step=time_step, port=port)
 
         # steering and throttle
-        self.action_space = spaces.Box(low=np.array([-1.0, 0.0]), high=np.array([1.0, 5.0]), dtype=np.float32 )
+        self.action_space = spaces.Box(low=np.array([self.STEER_LIMIT_LEFT, self.THROTTLE_MIN]),
+            high=np.array([self.STEER_LIMIT_RIGHT, self.THROTTLE_MAX]), dtype=np.float32 )
 
         # camera sensor data
-        self.observation_space = spaces.Box(0, 255, self.viewer.get_sensor_size(), dtype=np.uint8)
+        self.observation_space = spaces.Box(0, self.VAL_PER_PIXEL, self.viewer.get_sensor_size(), dtype=np.uint8)
 
         # simulation related variables.
         self.seed()

examples/ppo_train.py

@@ -35,14 +35,23 @@ def _init():
 
 if __name__ == "__main__":
 
+	# Initialize the donkey environment
+    # where env_name one of:    
+    env_list = [
+       "donkey-warehouse-v0",
+       "donkey-generated-roads-v0",
+       "donkey-avc-sparkfun-v0",
+       "donkey-generated-track-v0"
+    ]
+
     parser = argparse.ArgumentParser(description='ppo_train')
     parser.add_argument('--sim', type=str, default="sim_path", help='path to unity simulator. maybe be left at manual if you would like to start the sim on your own.')
     parser.add_argument('--headless', type=int, default=0, help='1 to supress graphics')
     parser.add_argument('--port', type=int, default=9091, help='port to use for tcp')
     parser.add_argument('--test', action="store_true", help='load the trained model and play')
     parser.add_argument('--multi', action="store_true", help='start multiple sims at once')
+    parser.add_argument('--env_name', type=str, default='donkey-generated-track-v0', help='name of donkey sim environment', choices=env_list)
 
-
     args = parser.parse_args()
 
     if args.sim == "sim_path" and args.multi:
@@ -54,7 +63,7 @@ def _init():
     os.environ['DONKEY_SIM_PORT'] = str(args.port)
     os.environ['DONKEY_SIM_HEADLESS'] = str(args.headless)
 
-    env_id = "donkey-generated-track-v0"
+    env_id = args.env_name
 
     if args.test: