how can speed up the code for solution in using gurobi? about the quad precision

Mu Yi

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Nov 19, 2016, 4:01:56 AM11/19/16

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Dear friends:

When I use gurobi solving a MIP problem, I have suffer a problem like this: the gurobi run about 18 hours, but it doesn't get the solution. (detail information see in figure)

It firstly use the simplex method but the software found it doesn't work. Then it switch to quad precision , how can I use the quad precision immediately?

1.png

2.png

Daniel Espinoza

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Nov 22, 2016, 5:55:02 AM11/22/16

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Hi Mu Yi,

the parameter is here: http://www.gurobi.com/documentation/7.0/refman/quad.html#parameter:Quad

Also, it might be that your model has numerical issues, did you get a warning about this? if so, is useful to think on reformulating your problem to improve its numerics.

Finally,

Could you share the model?

Best

Daniel

Kostja Siefen

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Nov 23, 2016, 3:37:17 AM11/23/16

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Quad precision is the last resort if your model has numerical issues. You should rescale your model.