Hello,
Anyone knows how to write the constraint that has ceiling function for
a variable in AMPL? I know that putting ceiling function of variables
in the mode makes the model to be NLP. But is there anyway that we can
put ceiling function in the IP or MIP model? I have tried this:
For Variable A, parameter b;
ceil(A/b) <==> t >= A/b and t <= A/b = 1 - epsilon, where epsilon
is the very small number. This thing works, however, it makes the
solve time increase (probably exponentially increase) very fast as the
problem size increases. Is there any other way to model this and not
cause the difficulty in computation.
Thank you very much.
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