from .OptimizationProblem import OptimizationProblem
import sys
import io
import gurobipy as gp
from gurobipy import Model, GRB, quicksum
import os
#This class is used to create Linear Programming (LP) models and can also be extended for Mixed Integer Linear Programming (MILP) models.
class LP(OptimizationProblem):
def __init__(self,problem: dict):
super().__init__( problem) #class create model
def _create_model(self):
#Direct all output to string buffer to suppress Gurobi console output
old_stdout = sys.stdout
old_stderr = sys.stderr
sys.stdout = io.StringIO()
sys.stderr = io.StringIO()
try:
self._model = Model(self._name)
self._model.setParam('OutputFlag', 0)
self._model.setParam('LogToConsole', 0)
self._addVariables()
if "quadratic_constraints" in self._constraints:
raise ValueError("Quadratic constraints are not supported in LP problems. Use QP or QCP for quadratic constraints.")
# Set the constraints
self._addLinearConstraints()
self._addLinearObjective()
except Exception as e:
print(f"An error occurred while creating the model: {e}")
self._model = None
raise e from e
finally:
sys.stdout = old_stdout
sys.stderr = old_stderr
