Originally posted by: LeonardH

Hello everyone,

sorry for the bad title but I just don't know how to explain it better.

I have the following problem:

I have a series of binaries (0 or 1). In this series, there shall always be at least three 1s after each other. Never only one or two 1s.

For example: No 0001000 or 00011000, but 0011100 is fine.

Now the first binary is x1, the second binary x2 and so on.

Does anyone know a way how to express the correct constraints to make my request possible?

Maybe I am overseeing a way how that is easily possible with CPLEX.

Thanks so much for your help, I am bit on a loss..!

Leo

Hi

could the following example help ?

int n=10;

dvar int x[1..n] in 0..1;

subject to
{


x[1]<=x[2];
x[n]<=x[n-1];

x[1]+x[2]-1<=x[3];
x[n]+x[n-1]-1<=x[n-2];

forall(i in 2..n-1) x[i]<=x[i+1]+x[i-1];
forall(i in 2..n-2) x[i]+x[i+1]-1<=x[i+2]+x[i-1];
}
 

what is the kind of business problem you intend to solve ?

regards

Originally posted by: LeonardH

Hey Alex,

I should have mentioned that I work with Matlab and use only the commands to do the optimization by CPLEX.

Is it possible to write your code in Matlab, so CPLEX "understands" it as well?

Thanks so much again!

Leo

Originally posted by: LeonardH

Regarding the kind of business problem:

I have some generators which have to be running for a certain amount of time before they can be shut down again. To make the constraints for that in CPLEX, I have to check that there are enough 1s after another before there is another zero!

Would be very glad if someone still has an idea or could answer the question regarding Alex' reply.

Leo