How to use a decision variable from optimization problem into an if else statement?
20 vues (au cours des 30 derniers jours)
Afficher commentaires plus anciens
Paramvir Singh
le 29 Avr 2018
Commenté : Amir Hossein Nazeri
le 5 Avr 2022
Here Tins is a decision variable of size=(24,1) in my optimization problem. The value of Tins(min_des) =20 while value of Tins(max_des) = 23. When I input the if else statement using Tins variable for value comparison, then the following error is shown by matlab:-
Please suggest the corrective measure. Thanks in advance
Réponse acceptée
Mary Fenelon
le 2 Mai 2018
The if-constraints (logical constraints, implication constraints) can be modeled with linear constraints and binary variables.
To see how to do this, suppose you have a binary variable y that should be 1 when x > 0. The constraint x - M*y <= 0, where M is an upper bound on x, will enforce this. When x > 0, y must be 1; the only other possible value for y is 0 and if y were 0, the constraint reduces to x <= 0, a contradiction.
To formulate constraint (6), make two constraints
- (Tmin - Tins) - M1*(1-BCac) <= 0 where M1 is an upper bound on (Tmin - Tins)
- (Tins - Tmax) - M2*BCac <= 0 where M2 is an upper bound on (Tins - Tmax)
The resulting constraints are called big-M constraints or indicator constraints. The y variable is called an indicator variable.
3 commentaires
Amir Hossein Nazeri
le 5 Avr 2022
@Paramvir Singh Hi Paramvir, Is your problem solved? Can you share your Matlab code with me if possible? Or if you have any Github or so...
Thanks!
Amir
Plus de réponses (0)
Voir également
Catégories
En savoir plus sur Get Started with Optimization Toolbox dans Help Center et File Exchange
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!