Global constraints with floats and reals

[3ashmawy]

Hello,

I am using EcLipse CLP on my linux box , and i was begining to create
a model for some financial optimization when i found out that
ic_global only deals with integers over lists. How can i use global
constraints like alldifferent, maxlist, sorted with floats and reals ?

Thank you,

Ahmed Ashmawy

[Kish Shen]

3ashmawy wrote:
> I am using EcLipse CLP on my linux box , and i was begining to create
> a model for some financial optimization when i found out that
> ic_global only deals with integers over lists. How can i use global
> constraints like alldifferent, maxlist, sorted with floats and reals ?

Real values only make sense in a continuous domain, and many of the
global constraints you cite only make sense as constraints, i.e.
reducing the size of the domains of variables involved in the
constraints, in a finite domain context -- i.e. where the domain consist
of a finite number of discrete values (usually represented as integers).

Why do you need floats in your model? If you only have discrete values,
you may be able to solve the problem by scaling or rounding the reals to
integers. On the other hand, if your optimisation problem involve using
traditional Mathematical Programming techniques and you are using
ECLiPSe's eplex interface to an external MP solver, you can directly
pass use integers (eplex converts these to floats that the solver expect
for you).

Cheers,

Kish Shen