Search found 4 matches

8 months ago
Forum: Tools
Topic: Select an element randomly from a multidimensional set
Replies: 3
Views: 390

Re: Select an element randomly from a multidimensional set

Thanks for your answers Clemens and dirkse. I thought about the answer 1) from Clemens but, unfortunately, my set s does not contain all the possible combination of the sets i, j, and k. I don't have 1.1.1, 1.1.2, 1.2.1, 1.2.2, 2.1.1, 2.1.2 ... But rather something like 1.1.2, 1.2.1, 2.1.1... Becaus...
8 months ago
Forum: Tools
Topic: Select an element randomly from a multidimensional set
Replies: 3
Views: 390

Select an element randomly from a multidimensional set

Hello, I have a problem for which I don't find a simple solution. I have a multidimensional set s(i,j,k). I would like to select randomly an element from this set. I was thinking about using randomNum = uniformint(1,card(s)) to select a random number between 1 and the number of elements in s. Then, ...
1 year ago
Forum: Solvers
Topic: Modifying the equations during the B&B or B&C algorithm
Replies: 2
Views: 1074

Re: Modifying the equations during the B&B or B&C algorithm

I understand this. The reason why I am asking this is because one of the constraint of my MILP problem contains a big-M parameter: variable(i) <= bigM(i)*(1-x(i)) where x is a binary variable. It turns out that, depending on how x(i) is bounded in the search tree, bigM(k) for k =/= i can be refined,...
1 year ago
Forum: Solvers
Topic: Modifying the equations during the B&B or B&C algorithm
Replies: 2
Views: 1074

Modifying the equations during the B&B or B&C algorithm

Hello, I would like to know whether it is possible to modify the constraints of a MILP problem at each node of the search tree. When going through the search tree of a MILP problem, at each node, we introduce some bounds on the integer variables. These bounds should allow me to refine the parameters...