How to create binary variables in Gurobi python interface?

Question

I am new to Gurobi Python interface. It would be great somebody guides me to this problem.

I want to create a Binary Decision variable using the Python interface.

The binary variable denoted by $X_{k, u, i, j}$ - indicates whether the task j of appliance i of user u at time slot k processed or not. 1 = processed , 0 = not processed.

I have tried like this,but not able to get the desired output.

 x = m.addVars(time_slots, users, appliances, task_appliances, vtype = GRB.BINARY, name = 'x')

Output

x[k1,u1,washingmachine, washingmachine], x[k1,u1,washingmachine, dryer]

Where 

time_slots = ['k1', 'k2','k3', 'k4', 'k5', 'k6', 'k7', 'k8', 'k9', 'k10']
users = ['u1', 'u2', 'u3', 'u4', 'u5']
appliances = ['washingmachine', 'dryer', 'dishwasher', 'refrigerator', 'gashob1', 'gashob2'] 



 task_appliances = {'washingmachine':['movement', 'heating','washing', 'cooling', '1strinse', '2ndrinse', '3rdrinse'], 'dryer': ['drying1', 'drying2', 'drying3', 'drying4', 'drying5', 'drying6', 'drying7', 'drying8'], 'dishwasher': ['movement', 'heating', 'wash', '1strinse', 'drain', 'heating','2ndrinse', 'drain_and_dry'], 'refrigerator': ['cooling1', 'cooling2', 'cooling3', 'cooling4','cooling5', 'cooling6', 'cooling7','cooling8', 'cooling9', 'cooling10'],'gashob1':['heating'], 'gashob2':['heating']}

How can i create a binary variable represents the x[k1,u1,washingmachine, movement], x[k1,u1,washingmachine, heating],.. like this for all washing machine tasks and x[k1,u1,dryer, drying1], x[k1,u1,dryer, drying2],.. like this for all dryer tasks and so on for all the appliances.

That looks correct - why do you say you do not "get the desired output" ? — Greg Glockner
– Greg Glockner, Commented Sep 28, 2018 at 19:03
No actually i am getting output like this, x[k1,u1,washingmachine, washingmachine], ` x[k1,u1,washingmachine, dryer]` — Praveenkumar Beedanal
– Praveenkumar Beedanal, Commented Sep 28, 2018 at 21:27

joni · Accepted Answer · 2018-09-29 09:43:58Z

1

First of all note that in task_appliances the task heating is twice for the dishwasher, after fixing this you could use a list comprehension to get a list of tuples and then use m.addVars():

from gurobipy import *

# Your lists here

m = Model()
vars_tup = [(t, u, app, task) for t in time_slots for u in users for app in appliances for task in task_appliances[app]]
x = m.addVars(vars_tup, vtype=GRB.BINARY, name="x")
# Your constraints and objective function..

answered Sep 29, 2018 at 9:43

joni

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2 Comments

Praveenkumar Beedanal Over a year ago

Actually dishwasher includes two heating task that's why i included heating twice.

joni Over a year ago

Then I recommend to rename them to heating1 and heating2 like you did for the other tasks. Otherwise m.addVars will yield a KeyError due to duplicate keys.

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