removed constraint on start location

flatland/envs/generators.py

@@ -681,7 +681,7 @@ def realistic_rail_generator(nr_start_goal=1, seed=0, add_max_dead_end=4, two_tr
             off_set = x_offsets[off_set_loop]
             # second track
             data = np.arange(2, width - 2)
-            n_track_seg = np.random.choice([1,2])
+            n_track_seg = np.random.choice([1, 2])
 
             track_2 = False
             if two_track_back_bone:

tests/test_flatland_env_sparse_rail_generator.py

@@ -9,29 +9,27 @@ from flatland.utils.rendertools import RenderTool, AgentRenderVariant
 
 
 def test_realistic_rail_generator(vizualization_folder_name=None):
-    for test_loop in range(50):
-        print("test_loop", test_loop)
-        num_agents = np.random.randint(10, 30)
-        env = RailEnv(width=np.random.randint(40, 80),
-                      height=np.random.randint(10, 20),
-                      rail_generator=realistic_rail_generator(nr_start_goal=num_agents + 1,
-                                                              seed=test_loop,
-                                                              add_max_dead_end=4,
-                                                              two_track_back_bone=test_loop % 2 == 0),
-                      number_of_agents=num_agents,
-                      obs_builder_object=GlobalObsForRailEnv())
-        # reset to initialize agents_static
-        env_renderer = RenderTool(env, gl="PILSVG", agent_render_variant=AgentRenderVariant.ONE_STEP_BEHIND,
-                                  screen_height=600,
-                                  screen_width=800)
-        env_renderer.render_env(show=True, show_observations=True, show_predictions=False)
-        if vizualization_folder_name is not None:
-            env_renderer.gl.save_image(
-                os.path.join(
-                    vizualization_folder_name,
-                    "flatland_frame_{:04d}.png".format(test_loop)
-                ))
-        env_renderer.close_window()
+    num_agents = np.random.randint(10, 30)
+    env = RailEnv(width=np.random.randint(40, 80),
+                  height=np.random.randint(10, 20),
+                  rail_generator=realistic_rail_generator(nr_start_goal=num_agents + 1,
+                                                          seed=test_loop,
+                                                          add_max_dead_end=4,
+                                                          two_track_back_bone=test_loop % 2 == 0),
+                  number_of_agents=num_agents,
+                  obs_builder_object=GlobalObsForRailEnv())
+    # reset to initialize agents_static
+    env_renderer = RenderTool(env, gl="PILSVG", agent_render_variant=AgentRenderVariant.ONE_STEP_BEHIND,
+                              screen_height=600,
+                              screen_width=800)
+    env_renderer.render_env(show=True, show_observations=True, show_predictions=False)
+    if vizualization_folder_name is not None:
+        env_renderer.gl.save_image(
+            os.path.join(
+                vizualization_folder_name,
+                "flatland_frame_{:04d}.png".format(0)
+            ))
+    env_renderer.close_window()
 
 
 def test_sparse_rail_generator():