Merge pull request #3766 from eminyouskn/knitro-load-solutions

Fix KNITRO solution status mapping

Author: blnicho

pyomo/contrib/solver/solvers/knitro/base.py

@@ -33,7 +33,6 @@
     NoReducedCostsError,
     NoSolutionError,
 )
-from pyomo.contrib.solver.solvers.knitro.api import knitro
 from pyomo.contrib.solver.solvers.knitro.config import KnitroConfig
 from pyomo.contrib.solver.solvers.knitro.engine import Engine
 from pyomo.contrib.solver.solvers.knitro.package import PackageChecker
@@ -204,57 +203,43 @@ def _get_items(self, item_type: type[ItemType]) -> Sequence[ItemType]:
 
     @staticmethod
     def _get_solution_status(status: int) -> SolutionStatus:
-        if (
-            status == knitro.KN_RC_OPTIMAL
-            or status == knitro.KN_RC_OPTIMAL_OR_SATISFACTORY
-            or status == knitro.KN_RC_NEAR_OPT
-        ):
+        """
+        Map KNITRO status codes to Pyomo SolutionStatus values.
+
+        See https://www.artelys.com/app/docs/knitro/3_referenceManual/returnCodes.html
+        """
+        if status in {0, -100}:
             return SolutionStatus.optimal
-        elif status == knitro.KN_RC_FEAS_NO_IMPROVE:
+        elif -101 >= status >= -199 or -400 >= status >= -409:
             return SolutionStatus.feasible
-        elif (
-            status == knitro.KN_RC_INFEASIBLE
-            or status == knitro.KN_RC_INFEAS_CON_BOUNDS
-            or status == knitro.KN_RC_INFEAS_VAR_BOUNDS
-            or status == knitro.KN_RC_INFEAS_NO_IMPROVE
-        ):
+        elif status in {-200, -204, -205, -206}:
             return SolutionStatus.infeasible
         else:
             return SolutionStatus.noSolution
 
     @staticmethod
     def _get_termination_condition(status: int) -> TerminationCondition:
-        if (
-            status == knitro.KN_RC_OPTIMAL
-            or status == knitro.KN_RC_OPTIMAL_OR_SATISFACTORY
-            or status == knitro.KN_RC_NEAR_OPT
-        ):
+        """
+        Map KNITRO status codes to Pyomo TerminationCondition values.
+
+        See https://www.artelys.com/app/docs/knitro/3_referenceManual/returnCodes.html
+        """
+        if status in {0, -100}:
             return TerminationCondition.convergenceCriteriaSatisfied
-        elif status == knitro.KN_RC_INFEAS_NO_IMPROVE:
+        elif status == -202:
             return TerminationCondition.locallyInfeasible
-        elif (
-            status == knitro.KN_RC_INFEASIBLE
-            or status == knitro.KN_RC_INFEAS_CON_BOUNDS
-            or status == knitro.KN_RC_INFEAS_VAR_BOUNDS
-        ):
+        elif status in {-200, -204, -205}:
             return TerminationCondition.provenInfeasible
-        elif (
-            status == knitro.KN_RC_UNBOUNDED_OR_INFEAS
-            or status == knitro.KN_RC_UNBOUNDED
-        ):
+        elif status in {-300, -301}:
             return TerminationCondition.infeasibleOrUnbounded
-        elif (
-            status == knitro.KN_RC_ITER_LIMIT_FEAS
-            or status == knitro.KN_RC_ITER_LIMIT_INFEAS
-        ):
+        elif status in {-400, -410}:
             return TerminationCondition.iterationLimit
-        elif (
-            status == knitro.KN_RC_TIME_LIMIT_FEAS
-            or status == knitro.KN_RC_TIME_LIMIT_INFEAS
-        ):
+        elif status in {-401, -411}:
             return TerminationCondition.maxTimeLimit
-        elif status == knitro.KN_RC_USER_TERMINATION:
+        elif status == -500:
             return TerminationCondition.interrupted
+        elif -500 > status >= -599:
+            return TerminationCondition.error
         else:
             return TerminationCondition.unknown
 

pyomo/contrib/solver/tests/solvers/test_knitro_direct.py

@@ -13,10 +13,11 @@
 from contextlib import redirect_stdout
 
 import pyomo.common.unittest as unittest
+import pyomo.environ as pyo
 
+from pyomo.contrib.solver.common.results import SolutionStatus, TerminationCondition
 from pyomo.contrib.solver.solvers.knitro.config import KnitroConfig
 from pyomo.contrib.solver.solvers.knitro.direct import KnitroDirectSolver
-import pyomo.environ as pyo
 
 avail = KnitroDirectSolver().available()
 
@@ -84,6 +85,54 @@ def test_available_cache(self):
         self.assertTrue(opt._available_cache)
         self.assertIsNotNone(opt._available_cache)
 
+    def test_solution_status_mapping(self):
+        opt = KnitroDirectSolver()
+        for opt_status in [0, -100]:
+            status = opt._get_solution_status(opt_status)
+            self.assertEqual(status, SolutionStatus.optimal)
+
+        for opt_status in [*range(-101, -103, -1), *range(-400, -406, -1)]:
+            status = opt._get_solution_status(opt_status)
+            self.assertEqual(status, SolutionStatus.feasible)
+
+        for opt_status in [-200, -204, -205, -206]:
+            status = opt._get_solution_status(opt_status)
+            self.assertEqual(status, SolutionStatus.infeasible)
+
+        for opt_status in [-501, -99999, -1]:
+            status = opt._get_solution_status(opt_status)
+            self.assertEqual(status, SolutionStatus.noSolution)
+
+    def test_termination_condition_mapping(self):
+        opt = KnitroDirectSolver()
+        for opt_status in [0, -100]:
+            term_cond = opt._get_termination_condition(opt_status)
+            self.assertEqual(
+                term_cond, TerminationCondition.convergenceCriteriaSatisfied
+            )
+        term_cond = opt._get_termination_condition(-202)
+        self.assertEqual(term_cond, TerminationCondition.locallyInfeasible)
+        for opt_status in [-200, -204, -205]:
+            term_cond = opt._get_termination_condition(opt_status)
+            self.assertEqual(term_cond, TerminationCondition.provenInfeasible)
+        for opt_status in [-300, -301]:
+            term_cond = opt._get_termination_condition(opt_status)
+            self.assertEqual(term_cond, TerminationCondition.infeasibleOrUnbounded)
+        for opt_status in [-400, -410]:
+            term_cond = opt._get_termination_condition(opt_status)
+            self.assertEqual(term_cond, TerminationCondition.iterationLimit)
+        for opt_status in [-401, -411]:
+            term_cond = opt._get_termination_condition(opt_status)
+            self.assertEqual(term_cond, TerminationCondition.maxTimeLimit)
+        term_cond = opt._get_termination_condition(-500)
+        self.assertEqual(term_cond, TerminationCondition.interrupted)
+        for opt_status in [-501, -550, -599]:
+            term_cond = opt._get_termination_condition(opt_status)
+            self.assertEqual(term_cond, TerminationCondition.error)
+        for opt_status in [-600, -99999, -1]:
+            term_cond = opt._get_termination_condition(opt_status)
+            self.assertEqual(term_cond, TerminationCondition.unknown)
+
 
 @unittest.skipIf(not avail, "KNITRO solver is not available")
 class TestKnitroDirectSolver(unittest.TestCase):