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<div class="moz-cite-prefix">James,</div>
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<div class="moz-cite-prefix">Try again with updated trunk. I think
it is connected to previous problems. What I think happened is
that the last SOS variable in a set is basic and computed as
1.0e-9. This is taken as non-zero as the default SOS tolerance is
1.0e-14. If the first variable is non-zero then it will branch
and fix the last variable to 0.0. However it looks feasible to
the LP and so the process is repeated.</div>
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<div class="moz-cite-prefix">Anyway see if changes help.</div>
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<div class="moz-cite-prefix">John<br>
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<div class="moz-cite-prefix">On 14/11/2018 00:47, James Howey wrote:<br>
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<p class="MsoNormal">I have a model that occasionally gets lost
in the weeds.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Cbc0010I After 6200 nodes, 4814 on tree,
1e+50 best solution, best possible 0 (97.67 seconds)<o:p></o:p></p>
<p class="MsoNormal">Cbc0020I Exiting on maximum time<o:p></o:p></p>
<p class="MsoNormal">Cbc0005I Partial search - best objective
1e+50 (best possible 0), took 549614 iterations and 6236 nodes
(100.02 seconds)<o:p></o:p></p>
<p class="MsoNormal">Cbc0035I Maximum depth 4816, 0 variables
fixed on reduced cost<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">My confusion stems from the reported
maximum depth of 4816. I have only 270 (sos) objects in the
model.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">It would seem that by the time I reach 270
I could judge this node integer feasible or not, and continue
in shallower depths. <o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Is this behavior by design, and if, as I
suspect, it is, are there situations where this strategy is
effective? Maybe even my situation?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Additional info: In my situation, there is
an order to the objects that will reliably give you an
infeasible/integer solution judgment by the time you reach
270. I have prioritized the objects in this order and turned
off strong branching. <o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">What would happen if I hacked the branch
decision logic to just never split the last level? Is branch
logic where I will be spending my time in the future?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks for any light you can shed.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">jkh<o:p></o:p></p>
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