<span style=" font-size:10pt;font-family:sans-serif">John,</span><br><br><span style=" font-size:10pt;font-family:sans-serif">thank you very
much, i will test the new trunk in the next few days.</span><br><br><span style=" font-size:10pt;font-family:sans-serif">If you want to
add the model to a test repository or suite feel free to do so.<br>As it seems to be kind of "special" or a rare combination so
no one faced that issue before</span><br><br><br><span style=" font-size:10pt;font-family:sans-serif">I also have another,
where cbc will not reach the right solution too, will check this too.</span><br><br><br><span style=" font-size:10pt;font-family:sans-serif">Thanks again</span><br><br><br><span style=" font-size:10pt;color:#808080;font-family:Arial">Mit freundlichen
Grüßen / Kind regards</span><br><span style=" font-size:12pt;color:#ffbf18;font-family:Calibri">________________________________________</span><br><br><span style=" font-size:12pt;font-family:Arial"><b>Pieter Zieschang</b></span><br><br><span style=" font-size:7pt;font-family:Arial"><b>Modis IT Outsourcing
GmbH</b></span><br><span style=" font-size:7pt;font-family:Arial">Atriumstraße 1, 04315
Leipzig</span><br><br><span style=" font-size:7pt;font-family:Arial">Amtsgericht Düsseldorf:
HRB 78227</span><br><span style=" font-size:7pt;font-family:Arial">Geschäftsführer: Martin
Wimmer, Jörg Brinkmann</span><br><br><a href=https://ito.modis.de/><span style=" font-size:10pt;color:blue;font-family:Arial">ito.modis.de</span></a><br><br><br><br><br><br><br><span style=" font-size:9pt;color:#5f5f5f;font-family:sans-serif">From:
</span><span style=" font-size:9pt;font-family:sans-serif">"John
Forrest" <jjhforrest@gmail.com></span><br><span style=" font-size:9pt;color:#5f5f5f;font-family:sans-serif">To:
</span><span style=" font-size:9pt;font-family:sans-serif">cbc@list.coin-or.org</span><br><span style=" font-size:9pt;color:#5f5f5f;font-family:sans-serif">Date:
</span><span style=" font-size:9pt;font-family:sans-serif">24.01.2020
18:57</span><br><span style=" font-size:9pt;color:#5f5f5f;font-family:sans-serif">Subject:
</span><span style=" font-size:9pt;font-family:sans-serif">Re:
[Cbc] wrong optimal solution - preprocess SOS - preprocess aggregate works
fine</span><br><span style=" font-size:9pt;color:#5f5f5f;font-family:sans-serif">Sent
by: </span><span style=" font-size:9pt;font-family:sans-serif">"Cbc"
<cbc-bounces@coin-or.org></span><br><hr noshade><br><br><br><tt><span style=" font-size:10pt">Pieter,<br><br>I think I have fixed the problem in trunk.<br><br>With some options, pre-processing tries to move costs from continuous <br>variables to integer variables - and when it does that the offset to the
<br>objective will change. It does this before presolving the problem.
<br>Your model has some fixed variables at non-zero values (which would have
<br>vanished in presolving). There was a section of the code in <br>CglPreProcess.cpp which got confused and adjusted the objective incorrectly.<br><br>When I ran the problem the solution values produced by the bad code were
<br>good, but the objective value did not match the correct value.<br><br>I have tested the changes on other models - but if anyone finds they <br>have problems, add -DSKIP_MOVE_COSTS_TO_INTEGERS to your configure AND
<br>inform me.<br><br>John Forrest<br><br><br><br>On 24/01/2020 09:18, Pieter Zieschang wrote:<br>> Hi Ted,<br>> <br>> the version is current trunk, as of January 22th.<br>> <br>> <br>> The problem is available for testing here: <br>> </span></tt><a href=https://mega.nz/#!c3Y0CA7R!jFnYcFVzcnYSWucZrCIdgb_AQzE5etB1JlySKom1QuE><tt><span style=" font-size:10pt">https://mega.nz/#!c3Y0CA7R!jFnYcFVzcnYSWucZrCIdgb_AQzE5etB1JlySKom1QuE</span></tt></a><tt><span style=" font-size:10pt"><br>> <br>> Command is in the post below.<br>> <br>> <br>> I'm not sure if i make it to opening an issue on github today.<br>> <br>> <br>> Thank you<br>> <br>> <br>> Mit freundlichen Grüßen / Kind regards<br>> ________________________________________<br>> <br>> *Pieter Zieschang*<br>> <br>> *Modis IT Outsourcing GmbH*<br>> Atriumstraße 1, 04315 Leipzig<br>> <br>> Amtsgericht Düsseldorf: HRB 78227<br>> Geschäftsführer: Martin Wimmer, Jörg Brinkmann<br>> <br>> ito.modis.de <</span></tt><a href=https://ito.modis.de/><tt><span style=" font-size:10pt">https://ito.modis.de/</span></tt></a><tt><span style=" font-size:10pt">><br>> <br>> <br>> <br>> <br>> <br>> <br>> From: "Ted Ralphs" <ted@lehigh.edu><br>> To: "Pieter Zieschang" <pieter.zieschang@modis.de><br>> Cc: "cbc" <cbc@list.coin-or.org><br>> Date: 24.01.2020 04:36<br>> Subject: Re: [Cbc] wrong optimal solution - preprocess SOS - preprocess
<br>> aggregate works fine<br>> ------------------------------------------------------------------------<br>> <br>> <br>> <br>> Hi Pieter,<br>> <br>> Forgive me if I missed something, but what Cbc version? Could you
open <br>> an issue on Github?<br>> <br>> Ted<br>> <br>> On Thu, Jan 23, 2020 at 5:23 AM Pieter Zieschang <br>> <_pieter.zieschang@modis.de_ <</span></tt><a href=mailto:pieter.zieschang@modis.de><tt><span style=" font-size:10pt">mailto:pieter.zieschang@modis.de</span></tt></a><tt><span style=" font-size:10pt">>>
wrote:<br>> Hello,<br>> <br>> there seems to be something going wrong when preprocess=sos (the <br>> default) is used, cbc selecting the wrong branch?<br>> <br>> When preprocess=aggregate the correct optimal solution is found, also
<br>> solution time is longer, probably the<br>> <br>> <br>> Correct Optimal Solution:<br>> <br>> $ cbc Problem_25581_0.mps timemode=elapsed -seconds=400 -keepNames=on
<br>> -threads=8 -dualt=1e-06 -perturb=on -pertvalue=61 -constraint=on <br>> -cuts=on -clique=forceon -zero=forceon -probing=forceonstrong <br>> -combine=on -combine2=on -ratiogap=0.001 -multiple=8 <br>> -preprocess=aggregate -solve<br>> <br>> Cbc0011I Exiting as integer gap of 3.0000005e-05 less than 1e-10 or
0.1%<br>> Cbc0001I Search completed - best objective 180.9999999999945, took
1048 <br>> iterations and 0 nodes (117.76 seconds)<br>> Cbc0035I Maximum depth 0, 289 variables fixed on reduced cost<br>> Cuts at root node changed objective from 177 to 181<br>> Probing was tried 108 times and created 793 cuts of which 0 were active
<br>> after adding rounds of cuts (1152.645 seconds)<br>> Gomory was tried 108 times and created 441 cuts of which 0 were active
<br>> after adding rounds of cuts (25.991 seconds)<br>> Knapsack was tried 108 times and created 18 cuts of which 0 were active
<br>> after adding rounds of cuts (9.414 seconds)<br>> Clique was tried 108 times and created 0 cuts of which 0 were active
<br>> after adding rounds of cuts (0.226 seconds)<br>> MixedIntegerRounding2 was tried 108 times and created 27 cuts of which
0 <br>> were active after adding rounds of cuts (15.430 seconds)<br>> FlowCover was tried 108 times and created 0 cuts of which 0 were active
<br>> after adding rounds of cuts (6.004 seconds)<br>> TwoMirCuts was tried 108 times and created 1530 cuts of which 0 were
<br>> active after adding rounds of cuts (33.287 seconds)<br>> ZeroHalf was tried 108 times and created 27 cuts of which 0 were active
<br>> after adding rounds of cuts (67.834 seconds)<br>> <br>> Result - Optimal solution found (within gap tolerance)<br>> <br>> Objective value:
181.00000000<br>> Lower bound: 181.000<br>> Gap: 0.00<br>> Enumerated nodes:
0<br>> Total iterations:
1048<br>> Time (CPU seconds): 656.08<br>> Time (Wallclock seconds): 121.02<br>> <br>> Total time (CPU seconds): 656.23 (Wallclock
seconds): 121.18<br>> <br>> <br>> <br>> <br>> <br>> Wrong Optimal Solution:<br>> <br>> $ cbc Problem_25581_0.mps timemode=elapsed -seconds=400 -keepNames=on
<br>> -threads=8 -dualt=1e-06 -perturb=on -pertvalue=61 -constraint=on <br>> -cuts=on -clique=forceon -zero=forceon -probing=forceonstrong <br>> -combine=on -combine2=on -ratiogap=0.001 -multiple=8 -solve<br>> Cbc0011I Exiting as integer gap of 49802 less than 1e-10 or 0.1%<br>> Cbc0001I Search completed - best objective 1200049979, took 0 iterations
<br>> and 0 nodes (67.05 seconds)<br>> Cbc0035I Maximum depth 0, 0 variables fixed on reduced cost<br>> Cuts at root node changed objective from 1.2e+09 to 1.2e+09<br>> Probing was tried 0 times and created 0 cuts of which 0 were active
<br>> after adding rounds of cuts (0.000 seconds)<br>> Gomory was tried 0 times and created 0 cuts of which 0 were active
after <br>> adding rounds of cuts (0.000 seconds)<br>> Knapsack was tried 0 times and created 0 cuts of which 0 were active
<br>> after adding rounds of cuts (0.000 seconds)<br>> Clique was tried 0 times and created 0 cuts of which 0 were active
after <br>> adding rounds of cuts (0.000 seconds)<br>> MixedIntegerRounding2 was tried 0 times and created 0 cuts of which
0 <br>> were active after adding rounds of cuts (0.000 seconds)<br>> FlowCover was tried 0 times and created 0 cuts of which 0 were active
<br>> after adding rounds of cuts (0.000 seconds)<br>> TwoMirCuts was tried 0 times and created 0 cuts of which 0 were active
<br>> after adding rounds of cuts (0.000 seconds)<br>> ZeroHalf was tried 0 times and created 0 cuts of which 0 were active
<br>> after adding rounds of cuts (0.000 seconds)<br>> Cgl0014I Postprocessing changed objective from 1.20005e+09 to 49979
- <br>> possible tolerance issue - try without preprocessing<br>> <br>> Result - Optimal solution found (within gap tolerance)<br>> <br>> Objective value:
1200049979.00000000<br>> Lower bound: 1200000177.000<br>> Gap: 0.00<br>> Enumerated nodes:
0<br>> Total iterations:
0<br>> Time (CPU seconds): 241.92<br>> Time (Wallclock seconds): 72.52<br>> <br>> Total time (CPU seconds): 242.06 (Wallclock
seconds): 72.68<br>> <br>> <br>> <br>> Thanks<br>> <br>> <br>> <br>> <br>> <br>> Mit freundlichen Grüßen / Kind regards<br>> ________________________________________<br>> *<br>> Pieter Zieschang*<br>> *<br>> Modis IT Outsourcing GmbH*<br>> Atriumstraße 1, 04315 Leipzig<br>> <br>> Amtsgericht Düsseldorf: HRB 78227<br>> Geschäftsführer: Martin Wimmer, Jörg Brinkmann<br>> _<br>> __ito.modis.de_ <</span></tt><a href=https://ito.modis.de/><tt><span style=" font-size:10pt">https://ito.modis.de/</span></tt></a><tt><span style=" font-size:10pt">><br>> <br>> <br>> Diese E-Mail und alle Anhänge sind vertraulich und für den Adressaten
<br>> bestimmt und können auch privilegiert oder von der Offenlegung nach
<br>> geltendem Recht ausgenommen sein. Wenn Sie nicht der Adressat sind
oder <br>> diese E-Mail irrtümlicherweise erhalten haben, benachrichtigen Sie
den <br>> Absender unverzüglich, löschen Sie die E-Mail aus Ihrem System und
<br>> kopieren Sie keine Teile dieser E-Mail oder deren Anhänge und geben
Sie <br>> sie nicht weiter.<br>> <br>> This email and any attachments are confidential and intended for the
<br>> addressee and may also be privileged or exempt from disclosure under
<br>> applicable law. If you are not the addressee, or have received this
<br>> email in error, please notify the sender immediately, delete it from
<br>> your system and do not copy, or disclose or otherwise act upon any
part <br>> of this email or its attachments.<br>> _______________________________________________<br>> Cbc mailing list_<br>> __Cbc@list.coin-or.org_ <</span></tt><a href="mailto:Cbc@list.coin-or.org"><tt><span style=" font-size:10pt">mailto:Cbc@list.coin-or.org</span></tt></a><tt><span style=" font-size:10pt">>_<br>> __</span></tt><a href="https://list.coin-or.org/mailman/listinfo/cbc_"><tt><span style=" font-size:10pt">https://list.coin-or.org/mailman/listinfo/cbc_</span></tt></a><tt><span style=" font-size:10pt"><br>> <br>> <br>> -- <br>> Dr. Ted Ralphs<br>> Professor, Industrial and Systems Engineering<br>> Lehigh University<br>> (610) 628-1280<br>> ted 'at' lehigh 'dot' edu_<br>> __coral.ie.lehigh.edu/~ted_ <</span></tt><a href=http://coral.ie.lehigh.edu/~ted><tt><span style=" font-size:10pt">http://coral.ie.lehigh.edu/~ted</span></tt></a><tt><span style=" font-size:10pt">><br>> <br>> Diese E-Mail und alle Anhänge sind vertraulich und für den Adressaten
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den <br>> Absender unverzüglich, löschen Sie die E-Mail aus Ihrem System und
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<br>> email in error, please notify the sender immediately, delete it from
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part <br>> of this email or its attachments.<br>> <br>> _______________________________________________<br>> Cbc mailing list<br>> Cbc@list.coin-or.org<br>> </span></tt><a href="https://list.coin-or.org/mailman/listinfo/cbc"><tt><span style=" font-size:10pt">https://list.coin-or.org/mailman/listinfo/cbc</span></tt></a><tt><span style=" font-size:10pt"><br>> <br><br>_______________________________________________<br>Cbc mailing list<br>Cbc@list.coin-or.org<br></span></tt><a href="https://list.coin-or.org/mailman/listinfo/cbc"><tt><span style=" font-size:10pt">https://list.coin-or.org/mailman/listinfo/cbc</span></tt></a><tt><span style=" font-size:10pt"><br></span></tt><br><br><font face="sans-serif"><div style="color:#968080; font-size: 12px;font-family:Arial">
Diese E-Mail und alle Anhänge sind vertraulich und für den Adressaten bestimmt und können auch privilegiert oder von der Offenlegung nach geltendem Recht ausgenommen sein. Wenn Sie nicht der Adressat sind oder diese E-Mail irrtümlicherweise erhalten haben, benachrichtigen Sie den Absender unverzüglich, löschen Sie die E-Mail aus Ihrem System und kopieren Sie keine Teile dieser E-Mail oder deren Anhänge und geben Sie sie nicht weiter.<br> <br>
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