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custom.py
#
# Copyright 2023, Gurobi Optimization, LLC
#
# Interactive shell customization example
#
# Define a set of customizations for the Gurobi shell.
# Type 'from custom import *' to import them into your shell.
#
from gurobipy import *
# custom read command -- change directory as appropriate
def myread(name):
return read('/home/jones/models/' + name)
# Custom termination criterion: Quit optimization
# - after 5s if a high quality (1% gap) solution has been found, or
# - after 10s if a feasible solution has been found.
def mycallback(model, where):
if where == GRB.Callback.MIP:
time = model.cbGet(GRB.Callback.RUNTIME)
best = model.cbGet(GRB.Callback.MIP_OBJBST)
bound = model.cbGet(GRB.Callback.MIP_OBJBND)
if best < GRB.INFINITY:
# We have a feasible solution
if time > 5 and abs(bound - best) < 0.01 * abs(bound):
model.terminate()
if time > 10:
model.terminate()
# custom optimize() function that uses callback
def myopt(model):
model.optimize(mycallback)
if __name__ == "__main__":
# Use as customized command line tool
import sys
if len(sys.argv) != 2:
print("Usage: python custom.py <model>")
m = read(sys.argv[1])
myopt(m)
