All Questions
40
questions
1
vote
1
answer
164
views
Non integer linear objective in or-tools CP-SAT
It seems that or-tools' CP-SAT solvers allows for non-integer coefficients in a linear objective expression. Am I correct, or is it just that the solver doesn't check for integrity and rounds the ...
- 11
1
vote
1
answer
269
views
Are there any hidden differences in OR-Tools' default parameters for a MIP model in Python vs C++?
or-tools-discuss cross post here.
As a disclaimer -- I am very aware that OR-Tools' Python code are just wrappers around their C++ source code. I'm just getting an odd discrepancy between a model ...
- 150
0
votes
1
answer
84
views
how the number of employees affects the married employee scheduling problem
My scheduling problem has a specific pattern of 2 days of work followed by 2 days off. Additionally, there is a week off after every 4 weeks of work. The scheduling matrix (P) has five different ...
- 11
1
vote
1
answer
683
views
TypeError: unsupported operand type(s) for *: 'IntVar' and 'float' in ortools [closed]
I am trying to implement a constraint as follows:
...
- 211
2
votes
1
answer
211
views
Control load per trip in multi trip VRP in ORTools
I have implemented multitrip VRP in ortools (To be specific, solved CVRPTW with virtual depots). Maximum number of trips per vehicle is limited to 2. I want to put a hard constraint that load carried ...
- 211
1
vote
1
answer
220
views
Applying weights to assignment problems for linear MIP solvers
In previous posts, A & B, I posed the Movie Theater Problem. In short, the movie theater problem encompasses assigning viewers to seats such that the distance between viewers is maximized, however,...
- 551
2
votes
2
answers
180
views
Mixed Integer Programming: Iterative assignment problem
I have a real world problem, which is analogous to the below toy problem, which I call 'The Movie Theater Problem' (TMTP.)
In TMTP, movie viewers are assigned seats which principally balances two ...
- 551
1
vote
1
answer
175
views
Simple Constraint Programming Problem: docplex works but equivalent ortools model is infeasible
I have a simple constraint programming model which can be solved using the docplex library, however I am struggling to implement the same model using ...
- 145
2
votes
1
answer
86
views
Circuit constraint leading to infeasibility if there are 0 jobs producable one a machine
Using the CP-SAT Solver:
My Model turns infeasible whenever there is no job available for a machine. Not every job can be built on every machine. Example Situtations:
Less jobs than machines
No jobs ...
- 35
2
votes
1
answer
323
views
Multiple Knapsack with Varying Values
I wish to assign customers to their nearest distribution hubs. These hubs have maximum capacities however, and if these are breached I would like to assign customers to the next most appropriate hub.
...
- 23
2
votes
1
answer
322
views
OR-Tools Cost Function Integration
I am modeling a problem similar to the job shop problem (tasks with start times, duration, and predecessors) and my objective is to minimize the makespan, with Python and OR-Tools.
start[i] is an ...
- 21
3
votes
2
answers
1k
views
Simple example of finding Hamiltonian path using Google OR-Tools?
I'd like to test how good/fast OR-Tools is in finding hamiltonian paths on some (big) directed graphs.
But I can't find simple enough (for me) examples.
Something like these ones (or even simpler), ...
- 59
1
vote
1
answer
349
views
Circuit constraint respecting the order of the next n jobs / jobs on each machine starting at 0
I am working on a scheduling problem in OR-Tools using the CP-SAT solver.
I'm working with
python but I managed to rebuild this solution as starting point:
Optimal way to ensure optional intervals are ...
- 35
6
votes
1
answer
916
views
Python "Coffee Shop Scheduling Problem" - Scheduling Lunches/Breaks
I'm working on an employee scheduling program in python. Having never done this before, I've been researching different libraries that can be used to accomplish the task.
Unfortunately, none of the ...
- 63
1
vote
0
answers
398
views
Adding sequence constraints to the assignment problem- Python
This is an online assignment problem and yet can be considered as an assignment problem with a sequence. Assume that workers are coming into the system sequentially and I want to assign a task to them ...
- 11