9
votes
Accepted
How to Model Path Being Only Through Adjacent Cells
A standard approach for modeling a path from source $s$ to sink $t$ in a directed graph with node set $N$ and arc set $A$ is to let continuous variable $x_{ij} \ge 0$ represent the flow along the arc $...
- 22.2k
5
votes
Additional resources for this type of problem formulation
The model looks really linear to me. After substituting out $V_{i,j}$ you have basically terms $x_{i,j}\cdot x_{k,j}$. Solvers may linearize that automatically or you must do it yourself. My guess is ...
- 1,571
4
votes
How to model Max-Cut as ILP
To start with maxcut, you can start with the maxcut example in how to with OPL ?
...
- 3,517
4
votes
Accepted
How to model Max-Cut as ILP
Let $V$ and $E$ be the sets of vertices and edges respectively. Define a binary variable $x_v$ for each vertex $v\in V$ to be 1 if the vertex is on the "left" side of the cut and 0 if it is ...
- 29.7k
3
votes
Accepted
cpu time in docplex
Yes , that's CPU time.
If you want real time then use the python time module
- 3,517
2
votes
Multiprocessor Scheduling Problem: How to modify some constraints after variable changing?
The condition (*), that every job is assigned to exactly one machine, simply requires $$\sum_{i=k}^n z_{i,k} \ge 1 \quad \forall i=1,\dots,n.$$ That ensures that every job belongs to a cluster. It ...
- 29.7k
2
votes
Accepted
Disjunctive Constraint , Using Binary Variable to Replace a If or condition
The usual approach to this requires that $b$ be bounded, say $L \le b \le U$ for some constants $L$ and $U.$ You can come close to what you want with the following: $$b \ge \pi (1-q) + L q$$ $$b \le \...
- 29.7k
Only top scored, non community-wiki answers of a minimum length are eligible