All Questions
40
questions
9
votes
3
answers
2k
views
Open source MILP solver for quick “good enough” solution
I have a problem that I have already posted elsewhere in OR.stack, but the question is focused around a large binary MILP (about 1 million decision variables). Ultimately, I am more time constrained ...
- 335
3
votes
0
answers
198
views
Power of variable or tools
I'm working with OR Tools in Python and I need to define the objective function an expression of the variables. In particular, the objective function is
$$\frac{c_j}{1.7^{s_j}}$$
with $c_j$ ...
- 131
10
votes
1
answer
2k
views
Floating points in OR-Tools
I'm trying to solve an RCPSPDc model (maximizing the net present value instead of a makespan). The objective function is: $\sum\limits_{j \in \text{Tasks}} e^{-\theta\cdot s_{j}}\cdot p_{j}$, where $...
6
votes
1
answer
367
views
Interface for Cbc - COIN-OR
I would like to code some IP/MIP models in python and test them with an open-source solver. As of now, I only know the Cbc - COIN-OR open-source solver.
I have already tried the or-tools interface, ...
- 1,193
8
votes
1
answer
760
views
Travelling salesman problem with given number of locations to visit
There's a great example here of how to find a solution to the travelling salesman problem:
...
- 271
6
votes
1
answer
1k
views
Constraint Programming OR-Tools finding Matrix Combinations
As a similar post of mine Find all Combinations of a Matrix I am trying to find matrix combinations with entries $>0$ meaning for a matrix
\begin{bmatrix}
0 & 1 & 3 \\
5 & 2 & 1 \\
...
- 1,193
9
votes
1
answer
624
views
TSP problem: traveller does not visit all nodes - Google OR-tools
Context:
I am dealing with a kind of scheduling problem, in which I have a set of tasks and machines. All tasks must be assigned to machines (not necessary all of them). In addition to that, I must ...
- 1,133
8
votes
3
answers
1k
views
Maximize assigned tasks to each worker
In a scheduling problem I want to assign the maximum number of tasks to one worker before assigning it to another. For example, if I have $10$ tasks and $2$ workers, the best assignment would be $(10, ...
- 1,414
4
votes
1
answer
467
views
Machine Allocation & optimal Utilization using python
Problem statement: Meet the demand which can be met across 2 facilities each having multiple machines where several components are made. The objective is to find the optimal solution to meet the ...
- 141
11
votes
1
answer
761
views
How to solve the Cumulative Traveling Salesman Problem using or-tools in python?
The objective of the Cumulative Traveling Salesman Problem (CTSP) is to minimize the sum of arrival times at customers, instead of the total travelling time. This is different than minimizing the ...
