CODEWITHSUNDEEP
ampl
hubert
hubert

Reputation: 933

Variable created from another variable in AMPL

In AMPL I have a set of variables x[e], for some calculations I need a binary variable w[e] which equals 1 when x[e] > 0 and 0 if x[e] = 0. I tried a lot of stuff to make this constraint, but I failed to come up with something. Is this possible?

Upvotes: 1

Views: 306

Answers (1)

bond_t
bond_t

Reputation: 141

I have solved your problem the following way:

var u  binary;

this is our binary variable that will be 0 or 1. Then we put following constraint:

subject to U_constraint :
    x <= 999999 * u;

Now when x = 0 then AMPL will make u = 0 and when x != 0 obviously u = 1.

Upvotes: 1

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