fixing issue rte-france#223

CHANGELOG.rst

@@ -37,6 +37,8 @@ Change Log
 - [FIXED]: some bugs in the `GreedyAgent` and `TopologyGreedy`
 - [FIXED]: `Issue#220 <https://github.com/rte-france/Grid2Op/issues/220>`_ `flow_bus_matrix` did not took into
   account disconnected powerlines, leading to impossibility to compute this matrix in some cases.
+- [FIXED]: `Issue#223 <https://github.com/rte-france/Grid2Op/issues/223>`_ : now able to plot a grid even
+  if there is nothing controllable in grid2op present in it.
 - [ADDED] support for the "alarm operator" / "attention budget" feature
 - [ADDED] retrieval of the `max_step` (ie the maximum number of step that can be performed for the current episode)
   in the observation

grid2op/PlotGrid/LayoutUtil.py

@@ -60,6 +60,10 @@ def layout_obs_sub_load_and_gen(obs, scale=1000.0, use_initial=False):
     gen_w = 25
     stor_w = 25
 
+    # add the nodes
+    for sub_id in range(obs.n_sub):
+        G.add_node(sub_id)
+
     # Set lines edges
     for line_idx in range(obs.n_line):
         lor_sub = obs.line_or_to_subid[line_idx]
@@ -107,9 +111,8 @@ def layout_obs_sub_load_and_gen(obs, scale=1000.0, use_initial=False):
         initial_layout = {}
         for sub_idx, sub_name in enumerate(layout_keys):
             sub_pos = copy.deepcopy(obs.grid_layout[sub_name])
-            #sub_pos[0] *= scale
-            #sub_pos[1] *= scale
             initial_layout[sub_idx] = sub_pos
+
         for load_idx, load_subid in enumerate(obs.load_to_subid):
             sub_name = layout_keys[load_subid]
             load_sub_pos = obs.load_to_sub_pos[load_idx]
@@ -119,6 +122,7 @@ def layout_obs_sub_load_and_gen(obs, scale=1000.0, use_initial=False):
             load_pos[0] += math.cos(load_sub_pos) * load_w
             load_pos[1] += math.sin(load_sub_pos) * load_w
             initial_layout[load_offset + load_idx] = load_pos
+
         for gen_idx, gen_subid in enumerate(obs.gen_to_subid):
             sub_name = layout_keys[gen_subid]
             gen_sub_pos = obs.gen_to_sub_pos[gen_idx]
@@ -145,8 +149,11 @@ def layout_obs_sub_load_and_gen(obs, scale=1000.0, use_initial=False):
         fix = list(range(obs.n_sub))
         seed = np.random.RandomState(0)
         # Use Fruchterman-Reingold algorithm
-        kkl = nx.spring_layout(G, scale=scale, fixed=fix,
-                               pos=initial_layout, seed=seed,
+        kkl = nx.spring_layout(G,
+                               scale=scale,
+                               fixed=fix,
+                               pos=initial_layout,
+                               seed=seed,
                                iterations=1000)
     else:
         # Use kamada_kawai algorithm

grid2op/Space/GridObjects.py

@@ -26,9 +26,9 @@
 from grid2op.Exceptions import *
 from grid2op.Space.space_utils import extract_from_dict, save_to_dict
 
-
 # TODO tests of these methods and this class in general
 
+
 class GridObjects:
     """
     INTERNAL
@@ -1745,10 +1745,11 @@ def assert_grid_correct_cls(cls):
 
         # no empty bus: at least one element should be present on each bus
         if np.any(cls.sub_info < 1):
-            # raise BackendError("There are {} bus with 0 element connected to it.".format(np.sum(cls.sub_info < 1)))
-            warnings.warn(f"There are {np.sum(cls.sub_info < 1)} substations where  no 'controlable' elements "
-                          f"are connected. These substations will be used in the computation of the powerflow "
-                          f"(by the backend) but you will NOT be able to control anything on them.")
+            if not grid2op.Space.space_utils._WARNING_ISSUED_FOR_SUB_NO_ELEM:
+                warnings.warn(f"There are {np.sum(cls.sub_info < 1)} substations where  no 'controlable' elements "
+                              f"are connected. These substations will be used in the computation of the powerflow "
+                              f"(by the backend) but you will NOT be able to control anything on them.")
+                grid2op.Space.space_utils._WARNING_ISSUED_FOR_SUB_NO_ELEM = True
 
         # redispatching / unit commitment
         if cls.redispatching_unit_commitment_availble:

grid2op/Space/space_utils.py

@@ -9,6 +9,10 @@
 import copy
 from grid2op.Exceptions import Grid2OpException
 
+# i already issued the warning for the "some substations have no controllable elements"
+_WARNING_ISSUED_FOR_SUB_NO_ELEM = False
+# this global variable is not const ! It is modified in GridObjects.py
+
 
 def extract_from_dict(dict_, key, converter):
     if key not in dict_:

grid2op/data_test/5bus_modif_grid/grid_layout.json

@@ -0,0 +1,30 @@
+{
+  "sub_0": [
+    0.0,
+    0.0
+  ],
+  "sub_1": [
+    0.0,
+    400.0
+  ],
+  "sub_2": [
+    200.0,
+    400.0
+  ],
+  "sub_3": [
+    400.0,
+    400.0
+  ],
+  "sub_4": [
+    400.0,
+    0.0
+  ],
+  "sub_5": [
+    500.0,
+    0.0
+  ],
+  "sub_6": [
+    400.0,
+    -100.0
+  ]
+}

grid2op/tests/test_issue_223.py

@@ -0,0 +1,46 @@
+# Copyright (c) 2019-2020, RTE (https://www.rte-france.com)
+# See AUTHORS.txt
+# This Source Code Form is subject to the terms of the Mozilla Public License, version 2.0.
+# If a copy of the Mozilla Public License, version 2.0 was not distributed with this file,
+# you can obtain one at http://mozilla.org/MPL/2.0/.
+# SPDX-License-Identifier: MPL-2.0
+# This file is part of Grid2Op, Grid2Op a testbed platform to model sequential decision making in power systems.
+
+import warnings
+
+import grid2op
+from grid2op.Chronics import ChangeNothing
+from grid2op.tests.helper_path_test import *
+try:
+    from grid2op.PlotGrid import PlotMatplot
+    CAN_PLOT = True
+except ImportError as exc_:
+    CAN_PLOT = False
+
+
+class Issue223Tester(unittest.TestCase):
+    def _skip_if_not_installed(self):
+        if not CAN_PLOT:
+            self.skipTest("matplotlib is not installed")
+
+    def setUp(self) -> None:
+        if CAN_PLOT:
+            with warnings.catch_warnings():
+                warnings.filterwarnings("ignore")
+                env_nm = os.path.join(PATH_DATA_TEST, "5bus_modif_grid")
+                self.env = grid2op.make(env_nm,
+                                        test=True,
+                                        chronics_class=ChangeNothing)
+                self.env.seed(0)
+                self.env.reset()
+
+    def test_env_working(self):
+        self._skip_if_not_installed()
+        with warnings.catch_warnings():
+            warnings.filterwarnings("error")  # there should be no warning there
+            # in the issue, it crashes there
+            plot_helper = PlotMatplot(self.env.observation_space)
+            assert "sub_5" in plot_helper._grid_layout
+            assert "sub_6" in plot_helper._grid_layout
+            # now test i can plot an observation
+            fig = plot_helper.plot_obs(self.env.reset())