Use compact variable features everywhere

This commit is contained in:
2021-04-15 09:49:35 -05:00
parent fec0113722
commit 95e326f5f6
11 changed files with 147 additions and 374 deletions

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@@ -10,8 +10,6 @@ from typing import TYPE_CHECKING, Dict, Optional, List, Hashable, Tuple
import numpy as np
from miplearn.types import Category
if TYPE_CHECKING:
from miplearn.solvers.internal import InternalSolver, LPSolveStats, MIPSolveStats
from miplearn.instance.base import Instance
@@ -49,49 +47,31 @@ class VariableFeatures:
user_features: Optional[Tuple[Optional[Tuple[float, ...]], ...]] = None
values: Optional[Tuple[float, ...]] = None
@dataclass
class Variable:
basis_status: Optional[str] = None
category: Optional[Hashable] = None
lower_bound: Optional[float] = None
obj_coeff: Optional[float] = None
reduced_cost: Optional[float] = None
sa_lb_down: Optional[float] = None
sa_lb_up: Optional[float] = None
sa_obj_down: Optional[float] = None
sa_obj_up: Optional[float] = None
sa_ub_down: Optional[float] = None
sa_ub_up: Optional[float] = None
type: Optional[str] = None
upper_bound: Optional[float] = None
user_features: Optional[List[float]] = None
value: Optional[float] = None
# Alvarez, A. M., Louveaux, Q., & Wehenkel, L. (2017). A machine learning-based
# approximation of strong branching. INFORMS Journal on Computing, 29(1), 185-195.
alvarez_2017: Optional[List[float]] = None
alvarez_2017: Optional[List[List[float]]] = None
def to_list(self) -> List[float]:
def to_list(self, index: int) -> List[float]:
features: List[float] = []
for attr in [
"lower_bound",
"obj_coeff",
"reduced_cost",
"lower_bounds",
"obj_coeffs",
"reduced_costs",
"sa_lb_down",
"sa_lb_up",
"sa_obj_down",
"sa_obj_up",
"sa_ub_down",
"sa_ub_up",
"upper_bound",
"value",
"upper_bounds",
"values",
]:
if getattr(self, attr) is not None:
features.append(getattr(self, attr))
features.append(getattr(self, attr)[index])
for attr in ["user_features", "alvarez_2017"]:
if getattr(self, attr) is not None:
features.extend(getattr(self, attr))
if getattr(self, attr)[index] is not None:
features.extend(getattr(self, attr)[index])
_clip(features)
return features
@@ -136,7 +116,6 @@ class Constraint:
class Features:
instance: Optional[InstanceFeatures] = None
variables: Optional[VariableFeatures] = None
variables_old: Optional[Dict[str, Variable]] = None
constraints: Optional[Dict[str, Constraint]] = None
lp_solve: Optional["LPSolveStats"] = None
mip_solve: Optional["MIPSolveStats"] = None
@@ -169,51 +148,16 @@ class FeaturesExtractor:
with_static=with_static,
with_sa=self.with_sa,
)
features.variables_old = self.solver.get_variables_old(
with_static=with_static,
)
features.constraints = self.solver.get_constraints(
with_static=with_static,
)
if with_static:
self._extract_user_features_vars(instance, features)
self._extract_user_features_vars_old(instance, features)
self._extract_user_features_constrs(instance, features)
self._extract_user_features_instance(instance, features)
self._extract_alvarez_2017(features)
return features
def _extract_user_features_vars_old(
self,
instance: "Instance",
features: Features,
) -> None:
assert features.variables_old is not None
for (var_name, var) in features.variables_old.items():
user_features: Optional[List[float]] = None
category: Category = instance.get_variable_category(var_name)
if category is not None:
assert isinstance(category, collections.Hashable), (
f"Variable category must be be hashable. "
f"Found {type(category).__name__} instead for var={var_name}."
)
user_features = instance.get_variable_features(var_name)
if isinstance(user_features, np.ndarray):
user_features = user_features.tolist()
assert isinstance(user_features, list), (
f"Variable features must be a list. "
f"Found {type(user_features).__name__} instead for "
f"var={var_name}."
)
for v in user_features:
assert isinstance(v, numbers.Real), (
f"Variable features must be a list of numbers. "
f"Found {type(v).__name__} instead "
f"for var={var_name}."
)
var.category = category
var.user_features = user_features
def _extract_user_features_vars(
self,
instance: "Instance",
@@ -312,72 +256,80 @@ class FeaturesExtractor:
)
def _extract_alvarez_2017(self, features: Features) -> None:
assert features.variables_old is not None
assert features.variables is not None
assert features.variables.names is not None
obj_coeffs = features.variables.obj_coeffs
obj_sa_down = features.variables.sa_obj_down
obj_sa_up = features.variables.sa_obj_up
values = features.variables.values
pos_obj_coeff_sum = 0.0
neg_obj_coeff_sum = 0.0
for (varname, var) in features.variables_old.items():
if var.obj_coeff is not None:
if var.obj_coeff > 0:
pos_obj_coeff_sum += var.obj_coeff
if var.obj_coeff < 0:
neg_obj_coeff_sum += -var.obj_coeff
if obj_coeffs is not None:
for coeff in obj_coeffs:
if coeff > 0:
pos_obj_coeff_sum += coeff
if coeff < 0:
neg_obj_coeff_sum += -coeff
for (varname, var) in features.variables_old.items():
assert isinstance(var, Variable)
features.variables.alvarez_2017 = []
for i in range(len(features.variables.names)):
f: List[float] = []
if var.obj_coeff is not None:
if obj_coeffs is not None:
# Feature 1
f.append(np.sign(var.obj_coeff))
f.append(np.sign(obj_coeffs[i]))
# Feature 2
if pos_obj_coeff_sum > 0:
f.append(abs(var.obj_coeff) / pos_obj_coeff_sum)
f.append(abs(obj_coeffs[i]) / pos_obj_coeff_sum)
else:
f.append(0.0)
# Feature 3
if neg_obj_coeff_sum > 0:
f.append(abs(var.obj_coeff) / neg_obj_coeff_sum)
f.append(abs(obj_coeffs[i]) / neg_obj_coeff_sum)
else:
f.append(0.0)
if var.value is not None:
if values is not None:
# Feature 37
f.append(
min(
var.value - np.floor(var.value),
np.ceil(var.value) - var.value,
values[i] - np.floor(values[i]),
np.ceil(values[i]) - values[i],
)
)
if var.sa_obj_up is not None:
assert var.obj_coeff is not None
assert var.sa_obj_down is not None
if obj_sa_up is not None:
assert obj_sa_down is not None
assert obj_coeffs is not None
# Convert inf into large finite numbers
sa_obj_down = max(-1e20, var.sa_obj_down)
sa_obj_up = min(1e20, var.sa_obj_up)
sd = max(-1e20, obj_sa_down[i])
su = min(1e20, obj_sa_up[i])
obj = obj_coeffs[i]
# Features 44 and 46
f.append(np.sign(var.sa_obj_up))
f.append(np.sign(var.sa_obj_down))
f.append(np.sign(obj_sa_up[i]))
f.append(np.sign(obj_sa_down[i]))
# Feature 47
csign = np.sign(var.obj_coeff)
if csign != 0 and ((var.obj_coeff - sa_obj_down) / csign) > 0.001:
f.append(log((var.obj_coeff - sa_obj_down) / csign))
csign = np.sign(obj)
if csign != 0 and ((obj - sd) / csign) > 0.001:
f.append(log((obj - sd) / csign))
else:
f.append(0.0)
# Feature 48
if csign != 0 and ((sa_obj_up - var.obj_coeff) / csign) > 0.001:
f.append(log((sa_obj_up - var.obj_coeff) / csign))
if csign != 0 and ((su - obj) / csign) > 0.001:
f.append(log((su - obj) / csign))
else:
f.append(0.0)
for v in f:
assert isfinite(v), f"non-finite elements detected: {f}"
var.alvarez_2017 = f
features.variables.alvarez_2017.append(f)
def _clip(v: List[float]) -> None: