Set solver constraints so variables are either 1 OR 0.

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Gwyndalf - 13 Jul 2006 00:40 GMT

I have an array which consists of some 100 variables but each can only be 1
or zero. (0.3 of a vehicle is meaningless!!!) If I place the constraints of

>=0 and <=1 and INT(all seperate line entries) the solver still wastes many

iterations with decimal numbers resulting in a long time to work out the
solution. The variables are used to specify the numbers of vehicle types
needed to tramsport a certain number of passengers. Each vehicle has a
different capacity and a different cost. I wish to find the cheapest
solution hence the variables array.

Can anyone offer a solution to the subject problem? Many Thanks.

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Dana DeLouis - 13 Jul 2006 00:57 GMT

> each can only be 1 or zero.
> the constraints of >=0 and <=1 and INT(all separate line entries).

One option would be to use the following instead.
For one of the constraints, add that A1:A100 are "bin." (The last item in
the pull-down menu).
bin means "Binary", which is the integer 0 or 1, and is designed to be a
little more efficient then the above code.
Hopefully this will help.

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Dana DeLouis
Windows XP, Office 2003

>I have an array which consists of some 100 variables but each can only be 1
> or zero. (0.3 of a vehicle is meaningless!!!) If I place the constraints
[quoted text clipped - 7 lines]
>
> Can anyone offer a solution to the subject problem? Many Thanks.

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Gwyndalf - 14 Jul 2006 01:16 GMT

Thanks for taking the time to reply.
The solver still comes up with decimal values despite using bin as the
constraint - I suspect that I must be thick!!!

> > each can only be 1 or zero.
> > the constraints of >=0 and <=1 and INT(all separate line entries).
[quoted text clipped - 16 lines]
> >
> > Can anyone offer a solution to the subject problem? Many Thanks.

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slebo - 28 May 2008 18:44 GMT

Did you ever get an answer? I am having the same exact problem.

> Thanks for taking the time to reply.
> The solver still comes up with decimal values despite using bin as the
[quoted text clipped - 20 lines]
> > >
> > > Can anyone offer a solution to the subject problem? Many Thanks.

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