yes I am aware that it only applies under somewhat special circumstances. However when it applies it could make a big difference in running time and thus be worth quite a lot.
If one is doing integer programing and have an objective function with integer coefficients then this should be applicable. If one wants to generalise one could also do this when the variables are integers and the coefficients are rational, since one can then in principle just multiply the objective function with the largest denominator present.
However for large denominators this could lead to very large integers in the objective function.
/Klas
Klas,
I think it makes sense to add the feature you mention; I don't think GLPK has it already, but I haven't checked the code for it.
Realize, however, that your situation is a special case in which all variables that appear in the objective are integer variables and all of their objective coefficients are integers as well. The rule you describe does not apply for general integer programs (even pure integer programs).
Brady
Klas Markstr�m wrote:Hi! I have been using glpsol to solve some minimisation integer programming problems. Right now the solver often finds the optimal integer solution with value opt fairly fast and then uses a lot of time to improve the lower bound from opt -1 to opt. Since the solver "knows" that this is an integer programming problem it should be able to stop as soon as it has improved the lower bound to anything strictly above the current optimum minus one.
Is this going to be changed in some upcoming version of glpsol or is there some simple way to change the code so it will stop as soon as it knows that the current best is the optimum?
/Klas
--
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Klas Markstr�m email: [EMAIL PROTECTED] Department of Mathematics fax: (+46)90 786 52 22 Ume� University phone: (+46)90 786 97 21 S-901 87 Umea, Sweden
URL: http://abel.math.umu.se/~klasm/
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-- Brady Hunsaker Assistant Professor Industrial Engineering University of Pittsburgh http://www.engr.pitt.edu/hunsaker/
--
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Klas Markstr�m email: [EMAIL PROTECTED] Department of Mathematics fax: (+46)90 786 52 22 Ume� University phone: (+46)90 786 97 21 S-901 87 Umea, Sweden
URL: http://abel.math.umu.se/~klasm/
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