Merge branch '66-shortest-path-predictor-cleanup-tests' into 'master'

Resolve "shortest-path-predictor"

Closes #66

See merge request flatland/flatland!65

flatland/envs/env_utils.py

@@ -10,7 +10,7 @@ import numpy as np
 from flatland.core.transitions import Grid4TransitionsEnum
 
 
-def get_direction(pos1, pos2):
+def get_direction(pos1, pos2) -> Grid4TransitionsEnum:
     """
     Assumes pos1 and pos2 are adjacent location on grid.
     Returns direction (int) that can be used with transitions.
@@ -25,7 +25,7 @@ def get_direction(pos1, pos2):
         return 1
     if diff_1 < 0:
         return 3
-    return 0
+    raise Exception("Could not determine direction {}->{}".format(pos1, pos2))
 
 
 def mirror(dir):
@@ -71,34 +71,71 @@ def validate_new_transition(rail_trans, rail_array, prev_pos, current_pos, new_p
     return rail_trans.is_valid(new_trans)
 
 
-def position_to_coordinate(width, position):
-    """
+def position_to_coordinate(depth, positions):
+    """Converts coordinates to positions:
+         [ (0,0) (0,1) ..  (0,w-1)
+           (1,0) (1,1)     (1,w-1)
+           ...
+           (d-1,0) (d-1,1)     (d-1,w-1)
+          ]
+
+         -->
 
-    :param width:
-    :param position:
+         [ 0      d    ..  (w-1)*d
+           1      d+1
+           ...
+           d-1    2d-1     w*d-1
+         ]
+
+    :param depth:
+    :param positions:
     :return:
     """
     coords = ()
-    for p in position:
-        coords = coords + ((int(p) % width, int(p) // width),)  # changed x_dim to y_dim
+    for p in positions:
+        coords = coords + ((int(p) % depth, int(p) // depth),)  # changed x_dim to y_dim
     return coords
 
 
-def coordinate_to_position(width, coords):
+def coordinate_to_position(depth, coords):
     """
-
-    :param width:
+    Converts positions to coordinates:
+         [ 0      d    ..  (w-1)*d
+           1      d+1
+           ...
+           d-1    2d-1     w*d-1
+         ]
+         -->
+         [ (0,0) (0,1) ..  (0,w-1)
+           (1,0) (1,1)     (1,w-1)
+           ...
+           (d-1,0) (d-1,1)     (d-1,w-1)
+          ]
+
+    :param depth:
     :param coords:
     :return:
     """
     position = np.empty(len(coords), dtype=int)
     idx = 0
     for t in coords:
-        position[idx] = int(t[1] * width + t[0])
+        position[idx] = int(t[1] * depth + t[0])
         idx += 1
     return position
 
 
+def get_new_position(position, movement):
+    """ Utility function that converts a compass movement over a 2D grid to new positions (r, c). """
+    if movement == Grid4TransitionsEnum.NORTH:
+        return (position[0] - 1, position[1])
+    elif movement == Grid4TransitionsEnum.EAST:
+        return (position[0], position[1] + 1)
+    elif movement == Grid4TransitionsEnum.SOUTH:
+        return (position[0] + 1, position[1])
+    elif movement == Grid4TransitionsEnum.WEST:
+        return (position[0], position[1] - 1)
+
+
 class AStarNode():
     """A node class for A* Pathfinding"""
 
@@ -254,18 +291,6 @@ def distance_on_rail(pos1, pos2):
     return abs(pos1[0] - pos2[0]) + abs(pos1[1] - pos2[1])
 
 
-def get_new_position(position, movement):
-    """ Utility function that converts a compass movement over a 2D grid to new positions (r, c). """
-    if movement == Grid4TransitionsEnum.NORTH:
-        return (position[0] - 1, position[1])
-    elif movement == Grid4TransitionsEnum.EAST:
-        return (position[0], position[1] + 1)
-    elif movement == Grid4TransitionsEnum.SOUTH:
-        return (position[0] + 1, position[1])
-    elif movement == Grid4TransitionsEnum.WEST:
-        return (position[0], position[1] - 1)
-
-
 def get_rnd_agents_pos_tgt_dir_on_rail(rail, num_agents):
     """
     Given a `rail' GridTransitionMap, return a random placement of agents (initial position, direction and target).

flatland/envs/predictions.py

@@ -112,7 +112,7 @@ class ShortestPathPredictorForRailEnv(PredictionBuilder):
         agents = self.env.agents
         if handle:
             agents = [self.env.agents[handle]]
-        assert custom_args
+        assert custom_args is not None
         distance_map = custom_args.get('distance_map')
         assert distance_map is not None
 

tests/envs/test_env_utils.py

+import numpy as np
+import pytest
+
+from flatland.core.transitions import Grid4TransitionsEnum
+from flatland.envs.env_utils import position_to_coordinate, coordinate_to_position, get_direction
+
+depth_to_test = 5
+positions_to_test = [0, 5, 1, 6, 20, 30]
+coordinates_to_test = [[0, 0], [0, 1], [1, 0], [1, 1], [0, 4], [0, 6]]
+
+
+def test_position_to_coordinate():
+    actual_coordinates = position_to_coordinate(depth_to_test, positions_to_test)
+    expected_coordinates = coordinates_to_test
+    assert np.array_equal(actual_coordinates, expected_coordinates), \
+        "converted positions {}, expected {}".format(actual_coordinates, expected_coordinates)
+
+
+def test_coordinate_to_position():
+    actual_positions = coordinate_to_position(depth_to_test, coordinates_to_test)
+    expected_positions = positions_to_test
+    assert np.array_equal(actual_positions, expected_positions), \
+        "converted positions {}, expected {}".format(actual_positions, expected_positions)
+
+
+def test_get_direction():
+    assert get_direction((0, 0), (0, 1)) == Grid4TransitionsEnum.EAST
+    assert get_direction((0, 0), (0, 2)) == Grid4TransitionsEnum.EAST
+    assert get_direction((0, 0), (1, 0)) == Grid4TransitionsEnum.SOUTH
+    assert get_direction((1, 0), (0, 0)) == Grid4TransitionsEnum.NORTH
+    assert get_direction((1, 0), (0, 0)) == Grid4TransitionsEnum.NORTH
+    with pytest.raises(Exception, match="Could not determine direction"):
+        get_direction((0, 0), (0, 0)) == Grid4TransitionsEnum.NORTH