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Option optcr

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0
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For MIQCPs Mosek seems to ignore the relative gap provided by GAMS (option optcr).

With either option opctr=0.1 (default) or optcr=0 (solve to optimality) I see:

An optimal solution satisfying the relative gap tolerance of 1.00e-002(%) has been located.
The relative gap is 9.36e-003(%).

Strangely enough for linear MIPs the optcr seems to work fine.  Well, almost. It does not seem to like a real zero gap.

So probably we have:

 

 OPTCRMosek gap tolerance 
MIP01.00e-002(%)almost ok
MIP0.11.00e+001(%)ok
MIQCP01.00e-002(%)almost ok
MIQCP0.11.00e-002(%)error

Most solvers produce a report in the listing file:

MIQP  Solution:      16305.625000    (12 iterations, 0 nodes)
Final Solve:         16301.875000    (0 iterations)

Best possible:       16222.656250
Absolute gap:           82.968750
Relative gap:            0.005088

which is helpful understanding the quality of the solution. Unfortunately Mosek does not do this (it writes nothing to the listing file except for some advertisement).


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