Skip to main content

Questions tagged [constraint-programming]

For questions on modeling satisfaction or optimization problems in languages designed for expressing (often high-level) constraints on decision variables.

31 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
7 votes
0 answers
80 views

Which Constraint solver is extensible to CSP algorithms?

I am novice to constraint programming and I need to implement the following algorithms. Backtacking Conflict-based backjumping AC partial lookahead MAC Forward checking Forward checking + dom ...
Cecelia's user avatar
  • 87
6 votes
0 answers
94 views

Graph coloring problem while counting cliques

Let $G$ be a graph with a set of nodes $V$ and a set of edges $E$. Let $G'$ be a graph with the same set of nodes $V$ but a second set of edges $E'$. For a set of nodes $X\subset V$, we denote $f(X)$ ...
Jin Kazama's user avatar
6 votes
0 answers
227 views

OptionalIntervalVar enforced but not working OR-TOOLS

I'm using OptionalIntervalVar and then maximizing the starts. The optimal solution is not affecting the other variables that creates the ...
Diego R. Troncoso's user avatar
6 votes
0 answers
166 views

Modelling issue with precedence constraint in OR-Tools

I'm trying to solve an RCPSPDc model It is infeasible, although Ilog Cplex solves it, so I think I have a modelling issue. I have more constraints but the precedence is the one that makes it ...
Diego R. Troncoso's user avatar
6 votes
0 answers
446 views

How to make constraints satisfy disciplined convex programming guidelines?

How do I turn my convex constraints (described below) into constraints that are DCP so that I can solve them in CVXPy? Is there some ``cheat sheet'' of standard tricks? I'm trying to implement the ...
Dupin's user avatar
  • 61
5 votes
0 answers
152 views

How to handle constraints in docplex to states the relation between two variables?

I am using docplex.cp and I need to state the following constraint: $$\sum_{c}(X_p{_w}_{cj}+X_{p+1}{_{w'}}_{cj+1})\leqslant T_w{_{w'}}_{,jj+1} + 1$$ Knowing that the binary variables are: $X_p{_w}_{...
campioni's user avatar
  • 1,133
5 votes
0 answers
42 views

In a binary logistic regression context, how to introduce a constraint to model the dependency between consecutive samples

Imagine we are running a logistic regression to identify opportunities for car sale promotion, using previous promotion campaign's result. Each $y$ is the increase of car sale after the promotion. ...
eight3's user avatar
  • 481
4 votes
0 answers
107 views

Modelling issue with rcpsp and boolean expressions

I'm trying to solve an RCPSPDc problem in OR-Tools with CP-SAT solver. In my RCPSPDc model (with discount rate) i want to set this objective: $$\max_{s}\sum_{j\in J}\text{profit}_{j}\cdot \frac{1}{(1+...
Diego R. Troncoso's user avatar
3 votes
0 answers
461 views

Circuit constraints in ortools

I am looking to assign tasks to people. Each successive task should be started after the first one is finished and should be started at the same location as the preceding task. While the time ...
Srikanth Shastry's user avatar
3 votes
0 answers
156 views

Convex Optimization Problem with norm inequality constraint

Consider the following optimization problem: \begin{align} \inf_{x,y}&\quad(x-x_0)^\top A(x-x_0) + (y-y_0)^\top B(y-y_0) \\\text{s.t.}&\quad x^\top a\geq0,\\ & \quad y^\top b\geq0, \\& ...
Apprentice's user avatar
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 $c_j$ ...
Clopen's user avatar
  • 131
2 votes
0 answers
98 views

log-log regression as reward function in optimization problem

Consider the model $\hat{y}_t = e^{\text{trend} + \text{seasonality}} \prod_k^K x_{k, t}^{b_k}$ where $K$ denotes different investment alternatives. You can think that trend and seasonality are ...
pete lewis's user avatar
2 votes
0 answers
60 views

System Stability constraints formulation

I am working with a system having a massless 2D plane and on that plane there is a rigid object with some mass placed on it. I want to support the plane with wooden sticks such that the system is ...
Ken Adams's user avatar
2 votes
0 answers
68 views

Multi-objective optimization with known variable dependencies (via a graph) -- what is this called?

Suppose that I am trying to solve a standard multi-objective optimization problem: $$ \min_{ \begin{array}{c} \textbf{x} \in S \end{array} } \left [ f_1(\textbf{x}),f_2(\...
Astrid's user avatar
  • 121
2 votes
0 answers
66 views

Assignment/scheduling how to formulate considering job time and job cost

I have the following problem that I do not know how to formulate. There are a fixed number of workers $w_i \in W$ for $i \in [1…N]$. Also, there are a fixed number of jobs that must be assigned to ...
Daniel Baquero's user avatar
2 votes
0 answers
77 views

Good encoding for grid layout problem

How would you encode the problem given by https://oeis.org/A337663 with an off-the-shelf solver? You need to lay out $n$ ones and $2, 3, ..., m$ on an infinite grid, for $m$ as large as possible. For ...
user1502040's user avatar
2 votes
0 answers
147 views

Multiple Depot/Crew Office Bus Driver Scheduling Modelling

I'm working on Bus Driver Schedule with multiple add-on constraints that are complex and hence trying to figure out how this can be achieved. Reference of Bus Driver Scheduling using OR-Tools:- https:/...
Brainiac's user avatar
2 votes
0 answers
92 views

Consistency Level of Constraints

Recently I started using CP and translated my first MIP model into a CP model with the IBM CP Optimizer. Lately I was confronted with a question I could not answer: "What is the consistency level ...
Dav's user avatar
  • 93
2 votes
0 answers
82 views

Finding Optimal Route using different Paths

I have a list of paths e.g. path 1 takes you from point A to B. A person needs to complete 5 of such paths. $$Route1 = path1 + ...
Lopez's user avatar
  • 205
2 votes
0 answers
176 views

Operation hours optimization for circular schedule

Here is my problem. A store has X = 15 electical devices with the ability to work non-stop, fully charged, up to 8 hours. Their battery charge lasts 2 hours and the operating hours of the store differ ...
Psyndrom Ventura's user avatar
2 votes
0 answers
66 views

Algorithm for Trainyard Marshall optimization problem

The problem I am trying to solve is the 2014 RAS problem. The link is the following The problem Trains come to the humpyard where each compartment of a train gets humped or disassembled and then each ...
Rio's user avatar
  • 21
1 vote
0 answers
55 views

Tents and trees constraints

I am trying to express the constraints for the 'Tents and trees' puzzle in minizinc but I am a bit stuck... I can express that each tent must be attached to at least one tree That a tree must be ...
user1454590's user avatar
1 vote
0 answers
63 views

Problems for which constraint programming is the state-of-the-art approach

What are examples of problems for which the state-of-the-art approach is constraint programming? Considering either heuristic or exact approaches. I'm looking for specific problems, not just a class ...
fontanf's user avatar
  • 2,623
1 vote
1 answer
181 views

Job Scheduling with Energy Consumption using Linear Programming

I'm looking for some advice for an optimization problem regarding scheduling jobs in a datacenter. So I have a list of jobs and each job has a required time for finishing and a number of cores it has ...
wind.leon's user avatar
1 vote
0 answers
112 views

Minimizing total number of banners used in the cover buildings problem modelled

I was watching a video about Google OR-Tools where they were solving this cover building problem from Codility challenges using constraint programming. In short, you have a list of building heights, e....
dabadaba's user avatar
  • 111
1 vote
0 answers
93 views

Question on quadratically constrained quadratic program

If the constrained optimization problem is a quadratically constrained quadratic program of the form \begin{align}\min&\quad x^HQx-a(x+x^H)+b|z^Hx|^2\\\text{s.t.}&\quad\|x\|^2\le1\end{align} ...
Kali's user avatar
  • 19
1 vote
0 answers
217 views

Fixed cost associated to SlackVar(waiting time cost) [CVRPTW]

I'm modeling a CVRPTW with some features: Each type of vehicle has a cost per km and a fixed cost per trip. To calculate these costs, I am using these methods for this: ...
Luiz Picanço's user avatar
0 votes
0 answers
59 views

Solving a multi depot multi vehicle capacitated routing problem using global constraints

I have built the model, but at this point, I am not sure how do I ensure that each fighter starts from the assigned depot and comes back to that depot. here is my code. The ...
Shahrukh Mohd's user avatar
0 votes
0 answers
104 views

Need Help for building two constraints in MIP model

Really need help for building two constraints with MIP model, I have written the required information and variable information on the diagram below. The way I think of it now is to use two ...
CangWangu's user avatar
0 votes
0 answers
60 views

Multilinear programming over the simplex

Let $\triangle_3 \in \mathbb{R}^3$ be the $3$-simplex. I am solving a series of multilinear programming problems that looks like this: $$\text{Maximize}\sum_{0\leq i, j, k \leq 3} A_{i,j,k} x_i x_j ...
AspiringMat's user avatar
-1 votes
1 answer
293 views

[OR-Tools][CP-SAT] Implement an indicator function in a constraint

Good morning ! I would like to implement this constraint using CP-SAT (see image below). x_i,j is a boolean variable, a and b are given. The problem is that I don't know how to implement the ...
Arthursbr's user avatar