[Cbc] two minor issues in cbc (maxtime and log)

[John Forrest]

Matt,

Fixed 2. (now says Lower or Upper)

Not doing 1. for now - most likely probing in preprocessing - obviously 
you can switch off preprocessing.

A less minor issue is that you want to solve this problem.  I would 
guess that there are 998,000 convexity rows for SOS - which is good for 
modeling but obviously not so good for the LP.  If they are convexity 
rows then it may be possible to take them out and add them back as cuts.

If you want, I can look at (a slightly smaller) problem to see what can 
be done.

John

On 23/01/18 02:06, Matthew Galati wrote:
>
> Two minor issues. This is through the C++ CBCModel API using the 
> latest CBC.
>
>  1. I set max time (1300 seconds), but CBC did not stop until after
>     19,900 seconds.
>  2. This is a maximization problem, but the final summary states
>     “Lower bound” for the bound. It might be cleaner to just say
>     “bound” – to avoid confusion.
>
> command line - cbc -solve -quit -seconds 1300 (default strategy 1)
>
> Continuous objective value is 1.88508e+09 - 855.75 seconds
>
> Cgl0005I 998000 SOS with 13941976 members
>
> Cgl0004I processed model has 999000 rows, 13941976 columns (13941976 
> integer (13                           941976 of which binary)) and 
> 26887952 elements
>
> Cutoff increment increased from 1e-05 to 0.9999
>
> Cbc0020I Exiting on maximum time
>
> Cbc0005I Partial search - best objective 1e+50 (best possible 
> -1.885078e+09), to 
>                                                                            ok 
> 0 iterations and 0 nodes (19624.31 seconds)
>
> Cbc0035I Maximum depth 0, 0 variables fixed on reduced cost
>
> Cuts at root node changed objective from -1.88508e+09 to -1.88508e+09
>
> Probing was tried 0 times and created 0 cuts of which 0 were active 
> after adding rounds of cuts (0.000 seconds)
>
> Gomory was tried 0 times and created 0 cuts of which 0 were active 
> after adding rounds of cuts (0.000 seconds)
>
> Knapsack was tried 0 times and created 0 cuts of which 0 were active 
> after addin 
>                                                                               g 
> rounds of cuts (0.000 seconds)
>
> Clique was tried 0 times and created 0 cuts of which 0 were active 
> after adding                                 rounds of cuts (0.000 
> seconds)
>
> MixedIntegerRounding2 was tried 0 times and created 0 cuts of which 0 
> were activ e after adding rounds of cuts (0.000 seconds)
>
> FlowCover was tried 0 times and created 0 cuts of which 0 were active 
> after addi ng rounds of cuts (0.000 seconds)
>
> TwoMirCuts was tried 0 times and created 0 cuts of which 0 were active 
> after add ing rounds of cuts (0.000 seconds)
>
> Result - Stopped on time limit
>
> No feasible solution found
>
> Lower bound: 1885078031.000
>
> Enumerated nodes:               0
>
> Total iterations:               0
>
> Time (CPU seconds):             19928.34
>
> Time (Wallclock seconds):       19973.07
>
> Total time (CPU seconds):       19930.87 (Wallclock seconds):       
> 19975.64
>
>
>
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