Use np.ndarray in Constraints

miplearn/solvers/gurobi.py

@@ -217,7 +217,7 @@ class GurobiSolver(InternalSolver):
         dual_value, basis_status, sa_rhs_up, sa_rhs_down = None, None, None, None
 
         if with_static:
-            rhs = model.getAttr("rhs", gp_constrs)
+            rhs = np.array(model.getAttr("rhs", gp_constrs), dtype=float)
             senses = model.getAttr("sense", gp_constrs)
             if with_lhs:
                 lhs = [None for _ in gp_constrs]
@@ -229,7 +229,7 @@ class GurobiSolver(InternalSolver):
                     ]
 
         if self._has_lp_solution:
-            dual_value = model.getAttr("pi", gp_constrs)
+            dual_value = np.array(model.getAttr("pi", gp_constrs), dtype=float)
             basis_status = list(
                 map(
                     _parse_gurobi_cbasis,
@@ -237,11 +237,13 @@ class GurobiSolver(InternalSolver):
                 )
             )
             if with_sa:
-                sa_rhs_up = model.getAttr("saRhsUp", gp_constrs)
-                sa_rhs_down = model.getAttr("saRhsLow", gp_constrs)
+                sa_rhs_up = np.array(model.getAttr("saRhsUp", gp_constrs), dtype=float)
+                sa_rhs_down = np.array(
+                    model.getAttr("saRhsLow", gp_constrs), dtype=float
+                )
 
         if self._has_lp_solution or self._has_mip_solution:
-            slacks = model.getAttr("slack", gp_constrs)
+            slacks = np.array(model.getAttr("slack", gp_constrs), dtype=float)
 
         return Constraints(
             basis_status=basis_status,

miplearn/solvers/internal.py

@@ -69,15 +69,15 @@ class Variables:
 @dataclass
 class Constraints:
     basis_status: Optional[List[str]] = None
-    dual_values: Optional[List[float]] = None
+    dual_values: Optional[np.ndarray] = None
     lazy: Optional[List[bool]] = None
     lhs: Optional[List[List[Tuple[str, float]]]] = None
     names: Optional[List[str]] = None
-    rhs: Optional[List[float]] = None
-    sa_rhs_down: Optional[List[float]] = None
-    sa_rhs_up: Optional[List[float]] = None
+    rhs: Optional[np.ndarray] = None
+    sa_rhs_down: Optional[np.ndarray] = None
+    sa_rhs_up: Optional[np.ndarray] = None
     senses: Optional[List[str]] = None
-    slacks: Optional[List[float]] = None
+    slacks: Optional[np.ndarray] = None
 
     @staticmethod
     def from_sample(sample: "Sample") -> "Constraints":
@@ -97,15 +97,19 @@ class Constraints:
     def __getitem__(self, selected: List[bool]) -> "Constraints":
         return Constraints(
             basis_status=self._filter(self.basis_status, selected),
-            dual_values=self._filter(self.dual_values, selected),
+            dual_values=(
+                None if self.dual_values is None else self.dual_values[selected]
+            ),
             names=self._filter(self.names, selected),
             lazy=self._filter(self.lazy, selected),
             lhs=self._filter(self.lhs, selected),
-            rhs=self._filter(self.rhs, selected),
-            sa_rhs_down=self._filter(self.sa_rhs_down, selected),
-            sa_rhs_up=self._filter(self.sa_rhs_up, selected),
+            rhs=(None if self.rhs is None else self.rhs[selected]),
+            sa_rhs_down=(
+                None if self.sa_rhs_down is None else self.sa_rhs_down[selected]
+            ),
+            sa_rhs_up=(None if self.sa_rhs_up is None else self.sa_rhs_up[selected]),
             senses=self._filter(self.senses, selected),
-            slacks=self._filter(self.slacks, selected),
+            slacks=(None if self.slacks is None else self.slacks[selected]),
         )
 
     def _filter(

miplearn/solvers/pyomo/base.py

@@ -236,11 +236,11 @@ class BasePyomoSolver(InternalSolver):
 
         return Constraints(
             names=_none_if_empty(names),
-            rhs=_none_if_empty(rhs),
+            rhs=_none_if_empty(np.array(rhs, dtype=float)),
             senses=_none_if_empty(senses),
             lhs=_none_if_empty(lhs),
-            slacks=_none_if_empty(slacks),
-            dual_values=_none_if_empty(dual_values),
+            slacks=_none_if_empty(np.array(slacks, dtype=float)),
+            dual_values=_none_if_empty(np.array(dual_values, dtype=float)),
         )
 
     @overrides

miplearn/solvers/tests/__init__.py

@@ -53,7 +53,7 @@ def run_basic_usage_tests(solver: InternalSolver) -> None:
         solver.get_constraints(),
         Constraints(
             names=["eq_capacity"],
-            rhs=[0.0],
+            rhs=np.array([0.0]),
             lhs=[
                 [
                     ("x[0]", 23.0),
@@ -108,11 +108,11 @@ def run_basic_usage_tests(solver: InternalSolver) -> None:
             solver.get_constraint_attrs(),
             Constraints(
                 basis_status=["N"],
-                dual_values=[13.538462],
+                dual_values=np.array([13.538462]),
                 names=["eq_capacity"],
-                sa_rhs_down=[-24.0],
-                sa_rhs_up=[2.0],
-                slacks=[0.0],
+                sa_rhs_down=np.array([-24.0]),
+                sa_rhs_up=np.array([2.0]),
+                slacks=np.array([0.0]),
             ),
         ),
     )
@@ -153,7 +153,7 @@ def run_basic_usage_tests(solver: InternalSolver) -> None:
             solver.get_constraint_attrs(),
             Constraints(
                 names=["eq_capacity"],
-                slacks=[0.0],
+                slacks=np.array([0.0]),
             ),
         ),
     )
@@ -162,7 +162,7 @@ def run_basic_usage_tests(solver: InternalSolver) -> None:
     cf = Constraints(
         names=["cut"],
         lhs=[[("x[0]", 1.0)]],
-        rhs=[0.0],
+        rhs=np.array([0.0]),
         senses=["<"],
     )
     assert_equals(solver.are_constraints_satisfied(cf), [False])
@@ -175,7 +175,7 @@ def run_basic_usage_tests(solver: InternalSolver) -> None:
             solver.get_constraint_attrs(),
             Constraints(
                 names=["eq_capacity", "cut"],
-                rhs=[0.0, 0.0],
+                rhs=np.array([0.0, 0.0]),
                 lhs=[
                     [
                         ("x[0]", 23.0),
@@ -274,7 +274,7 @@ def _equals_preprocess(obj: Any) -> Any:
             return np.round(obj, decimals=6).tolist()
         else:
             return obj.tolist()
-    elif isinstance(obj, (int, str)):
+    elif isinstance(obj, (int, str, bool, np.bool_)):
         return obj
     elif isinstance(obj, float):
         return round(obj, 6)

tests/features/test_extractor.py

@@ -122,7 +122,7 @@ def test_knapsack() -> None:
 def test_constraint_getindex() -> None:
     cf = Constraints(
         names=["c1", "c2", "c3"],
-        rhs=[1.0, 2.0, 3.0],
+        rhs=np.array([1.0, 2.0, 3.0]),
         senses=["=", "<", ">"],
         lhs=[
             [
@@ -143,7 +143,7 @@ def test_constraint_getindex() -> None:
         cf[[True, False, True]],
         Constraints(
             names=["c1", "c3"],
-            rhs=[1.0, 3.0],
+            rhs=np.array([1.0, 3.0]),
             senses=["=", ">"],
             lhs=[
                 [