Questions tagged [cp-sat]
The cp-sat tag has no usage guidance.
27
questions
1
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3
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389
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Google-OR Tools: Assignment minimizing overlapping members
I'm rusty on constraint optimization and am looking for help in this particular use case. There are individuals who are each member to several teams. This is a fixed many-to-many relationship and is ...
- 1,275
2
votes
2
answers
205
views
OR-Tools CP-SAT solver: is it possible to name a constraint like in GUROBI
I try to implement cp model with OR-tools CP-SAT solver. Please, is it possible to name constraints for being able to manage conflict later like for variables:
...
- 3,343
1
vote
1
answer
92
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 ...
- 2,597
0
votes
2
answers
67
views
Formulating assignment problem with people attributes that need to be balanced per assignment attribute in or-tools, CP-sat
I'm trying to do an assignment problem with the following characteristics:
I have two sets that need to be matched with each other, set A (Students) and set B (Class combinations). Set A and B have ...
- 3,343
0
votes
1
answer
111
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Using binary variable or integer variable in Constraint Programming (CP)?
I am trying to solve an assignment problem by Constraint Programming (CP). Let us consider a task assignment problem that have $|M|$ tasks and $|N|$ machines, each task has different processing time ...
- 2,597
0
votes
1
answer
107
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Team Orienteering Problem with Time Windows infeasible using CP-SAT solver in Google OR-Tool
I am developing a TOPTW where there are a set of N nodes. Each node i is associated with a visit time, which is also the score Si. The starting point and the end point of each tour is fixed, which is ...
- 2,597
3
votes
2
answers
142
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how to count the number of values that are greater than zero in OR-Tools
I am using OR-Tools for an employees scheduling problem. I have a dictionary that is defined as an IntVar, where such dictionary contains the number of hours that will be assigned to each employee, ...
- 1,885
2
votes
1
answer
857
views
What exactly does the AddHint() method in Google OR-Tools' CP-SAT solver do?
I have an optimization problem that I am solving with CP-SAT and I am using the Python interface. Moreover, I know a good feasible solution coming from a heuristic and I want the solver to start its ...
- 2,597
3
votes
1
answer
1k
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CP-SAT _ Summing variables under conditions
I have been working lately on scheduling optimization using CP-SAT in OR-TOOLS and now I'm at the point where I need to start considering due dates in my model.
I didn't want to put them as ...
- 2,597
-1
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1
answer
209
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[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 ...
- 3,343
1
vote
1
answer
472
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About circuit constraints in OR - tools
I am trying to implement a scheduling problem to solve with CP-SAT from OR-tools. There, in particular, for every machine I want to add a time transition constraint from every task that is performed ...
- 2,597
3
votes
1
answer
135
views
CP-SAT's `NumBooleans()` parameter
The solver API for CP-SAT offers the attribute NumBooleans, which is documented as "Returns the number of boolean variables managed by the SAT solver".
...
- 2,597
4
votes
1
answer
305
views
Relevance of order of model construction in CP-SAT
Question 1: Is ortool's CP-SAT sensitive to the order in which a model is constructed?
In other words, does it matter which variables and constraints come first?
I am seeing a high performance ...
- 2,597
2
votes
2
answers
179
views
Parallel scheduling with precedence constraints and variable job length
I have $N$ jobs and $M$ machines and want to minimize the makespan, i.e. the total time to finish all jobs. Some jobs have precedence constraints and can only be started once other jobs are finished. ...
- 2,597
2
votes
1
answer
174
views
Scheduling optimization, Adding 4 day same shift and 3 day off weekly constraint
Am writing a small scheduling program in C# for a group of 7 staff who will be working in three shifts daily for 4 weeks. Am using the google OR-Tools Template, but i have modified it abit
This is the ...
- 3,343
1
vote
1
answer
288
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 ...
- 2,597
3
votes
1
answer
149
views
"Complex" scheduling problem model structure
So, I'm modelling a job assigning problem in OR-Tools CP-SAT. I want to maximize rescheduled jobs based on some constraints. Right now jobs in my model look like this:
...
- 2,597
3
votes
0
answers
437
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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 ...
- 2,597
0
votes
1
answer
217
views
or-tools: job shop problem never exists not finding additional solutions
I am trying to solve a flexible job shop problem variant using or-tools.
And in some input configuration, in general after one month of scheduling time, I am facing a weird behavior.
I am aware that ...
- 2,597
1
vote
2
answers
236
views
Google CP-SAT Infeasible ILP for Large Problem Area
I am trying to generate a shortest path between source and sink in a square grid of cells. I am using the Google CP-SAT solver ...
- 2,597
1
vote
1
answer
154
views
Modeling Multi-Agent Collision in Google CP-SAT Solver
I would like to implement a solution for Multi-Agent Pathfinding Problem using Google's CP-SAT Solver.
How do I implement the constraint that prohibits 2 or more agents from occupying the same cell at ...
- 2,597
3
votes
1
answer
266
views
Force gaps between tasks, tasks are scheduled within their job's time windows in Jobshop problem
The problem I'm trying to solve is a modification of the original Jobshop problem. The additional constraints are:
There is only one machine for all jobs and their tasks.
Each job has a priority (...
- 2,597
2
votes
1
answer
362
views
CP-SAT solver doesn't use all space available for scheduling
This problem is a continuation of this problem. The issue here is the solver doesn't use the whole space available for the scheduling and thus some jobs are not being scheduled. For example: we need ...
- 2,597
2
votes
1
answer
199
views
RAM overflow when scheduling 1000+ intervals
Due to the answers to this and this questions, I was able to find the optimal solution for scheduling problem. However, if there are many tasks that must be scheduled, e.g. 1000+, then the solver ...
- 2,597
1
vote
1
answer
137
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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 ...
- 2,597
3
votes
0
answers
175
views
Can Pyomo be linked with Google's GLOP or CP-SAT solvers?
Pyomo can be linked with several solvers Open source and commercial ones.
I was wondering if Pyomo can be linked with Google's GLOP or CP-SAT solvers?
- 2,597
2
votes
1
answer
81
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 ...
- 2,597