from .OptimizationProblem import OptimizationProblem
import sys
import io
import gurobipy as gp
from gurobipy import Model, GRB, quicksum
#This class is used to create Qudratic Programming (QP) models and can also be extended for Mixed Integer Quadratic Programming (MIQP) models.
class QP(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
try:
old_stdout = sys.stdout
old_stderr = sys.stderr
sys.stdout = io.StringIO()
sys.stderr = io.StringIO()
self._model = Model(self._name)
self._model.setParam('OutputFlag', 0)
self._model.setParam('LogToConsole', 0)
self._addVariables() # Add variables to the model
self._addLinearConstraints() # Add linear constraints to the model
if "quadratic_constraints" in self._constraints and len(self._constraints["quadratic_constraints"]) > 0:
raise ValueError("Quadratic constraints are not supported in QP problems. Use QCP for quadratic constraints.")
self._addQuadraticObjective() # Add quadratic objective function to the model
except Exception as e:
self._model = None
raise e from e
finally:
# Change output back to console
sys.stdout = old_stdout
sys.stderr = old_stderr
