Merge pull request #51 from LucasAlegre/hotfix/recover-solver-error-ols

Recover from solver error in OLS

examples/pcn_minecart.py

@@ -24,6 +24,7 @@ def make_env():
     )
 
     agent.train(
+        eval_env=make_env(),
         total_timesteps=int(1e7),
         ref_point=np.array([0, 0, -200.0]),
         num_er_episodes=20,

morl_baselines/multi_policy/linear_support/linear_support.py

@@ -6,6 +6,7 @@
 import cdd
 import cvxpy as cp
 import numpy as np
+from cvxpy import SolverError
 from gymnasium.core import Env
 
 from morl_baselines.common.evaluation import policy_evaluation_mo
@@ -289,7 +290,12 @@ def max_value_lp(self, w_new: np.ndarray) -> float:
         # such that it is consistent with other optimal values for other visited weights
         constraints = [W @ v <= V]
         prob = cp.Problem(objective, constraints)
-        return prob.solve(verbose=False)
+        try:
+            result = prob.solve(verbose=False)
+        except SolverError:
+            print("ECOS solver error, trying another one.")
+            result = prob.solve(solver=cp.SCS, verbose=False)
+        return result
 
     def compute_corner_weights(self) -> List[np.ndarray]:
         """Returns the corner weights for the current set of values.