Problem with the product of integer and binary variables

Archive of Gamsworld Google Group
Post Reply
Archiver
User
User
Posts: 7876
Joined: 7 years ago

Problem with the product of integer and binary variables

Post by Archiver »




i am trying to maximize obj=sum(t,C*y(t)).
t is the set /1*10/.

when i try to maximize/minimize, it is choosing small C(say 14) and
takes all binary variables as 1. But i am interested in C greater than
50. it is showning infeasible soln. i want C to be big and y(t) should
be combiantions of 0's and 1's. Could anyone suggest, why this
product combination is not working. why binary variable is not
changing.

--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to gamsworld@googlegroups.com
To unsubscribe from this group, send email to gamsworld+unsubscribe@googlegroups.com
For more options, visit this group at http://groups.google.com/group/gamsworld?hl=en
-~----------~----~----~----~------~----~------~--~---


Archiver
User
User
Posts: 7876
Joined: 7 years ago

Re: Problem with the product of integer and binary variables

Post by Archiver »



I don't get this. If this is the only part of the model the maximum is
clearly reached if you set all your binary variables to one. I don't
understand why things would change as long as C is positive. If C
becomes negative, all binaries will switch to 0. There is probably
more to it, so you might want to send your complete GAMS model.

Hope this helps,
Michael Bussieck - GAMSWorld Coordinator

On Sep 28, 2:38 pm, swin wrote:
> > i am trying to maximize obj=sum(t,C*y(t)).
> > t is the set /1*10/.
> >
> > when i try to maximize/minimize, it is choosing small C(say 14) and
> > takes all binary variables as 1. But i am interested in C greater than
> > 50. it is showning infeasible soln. i want C to be big and y(t) should
> > be combiantions of 0's and 1's. Could anyone suggest, why this
> > product combination is not working. why binary variable is not
> > changing.
--~--~---------~--~----~------------~-------~--~----~
To post to this group, send email to gamsworld@googlegroups.com
To unsubscribe from this group, send email to gamsworld+unsubscribe@googlegroups.com
For more options, visit this group at http://groups.google.com/group/gamsworld?hl=en
-~----------~----~----~----~------~----~------~--~---


Post Reply