<div dir="ltr"><div>Dear All,</div><div><br></div><div>I am trying to solve an MINLP using bonmin. It reported the MINLP as infeasible problem while during the iterations I see some feasible solutions. My question are:</div>
<div><br></div><div>1. why does bonmin conclude it as infeasible problem? </div><div>2. why not it gives the feasible solution even if it is not locally optimal?</div><div><br></div><div>For your consideration, I put an example of bonmin output at the end of this email. (bb_log_level 1).</div>
<div><br></div><div><br></div><div>I am thankful for your kind attention and help.</div><div><br></div><div>Sincerely Yours,</div><div><br></div><div>Novalio Daratha</div><div>PhD student</div><div>IIT Roorkee</div><div>India</div>
<div><br></div><div><br></div><div><br></div><div>Bonmin 1.5.2 using Cbc 2.7.6 and Ipopt 3.10.2</div><div>bonmin:</div><div><br></div><div>******************************************************************************</div>
<div>This program contains Ipopt, a library for large-scale nonlinear optimization.</div><div> Ipopt is released as open source code under the Eclipse Public License (EPL).</div><div> For more information visit <a href="http://projects.coin-or.org/Ipopt">http://projects.coin-or.org/Ipopt</a></div>
<div>******************************************************************************</div><div><br></div><div>NOTE: You are using Ipopt by default with the MUMPS linear solver.</div><div> Other linear solvers might be more efficient (see Ipopt documentation).</div>
<div><br></div><div><br></div><div>NLP0012I</div><div> Num Status Obj It time Location</div><div>NLP0014I 1 FAILED 0.0044821868 3000 8.388</div>
<div>NLP0014I 1 FAILED 0.0044678956 3000 7.652 resolve robustness</div><div>NLP0014I 3 OPT 0.0041219542 1030 3.17</div><div>NLP0012I</div><div> Num Status Obj It time Location</div>
<div>NLP0014I 1 INFEAS 1 54 0.144</div><div>NLP0014I 4 FAILED 1.2200549 3000 7.826</div><div>NLP0014I 5 FAILED 1.2400101 3000 8.146</div><div>NLP0014I 6 FAILED 1.2413622 3000 8.007</div>
<div>NLP0014I 7 FAILED 1.2398611 3000 7.769</div><div>NLP0014I 8 FAILED 0.03787479 3000 7.779</div><div>NLP0014I 9 FAILED -0.070294006 3000 7.33</div><div>NLP0014I 10 FAILED 0.0044563366 3000 7.775</div>
<div>NLP0014I 11 FAILED -0.070344772 3000 7.33</div><div>NLP0014I 12 FAILED 1.2242858 3000 7.964</div><div>NLP0014I 13 FAILED -0.070401127 3000 7.064</div><div>NLP0014I 14 FAILED 1.2470022 3000 7.639</div>
<div>NLP0014I 15 FAILED -0.070728211 3000 6.996</div><div>NLP0014I 16 OPT 0.0041219556 945 2.374</div><div>NLP0014I 17 FAILED -0.070781423 3000 6.949</div><div>
NLP0014I 18 FAILED 0.0044845077 3000 7.292</div><div>NLP0014I 19 FAILED -0.069781992 3000 7.329</div><div>NLP0014I 20 FAILED 0.0045109264 3000 7.359</div><div>NLP0012I</div>
<div> Num Status Obj It time Location</div><div>NLP0014I 21 FAILED -0.070408086 3000 7.094</div><div>NLP0014I 22 FAILED 0.0045273783 3000 7.419</div>
<div>NLP0014I 23 FAILED -0.070202589 3000 7.304</div><div>NLP0014I 24 FAILED 0.0054378863 3000 7.413</div><div>NLP0014I 25 FAILED -0.068064574 3000 7.261</div><div>
NLP0014I 26 OPT 0.0041219556 6 0.012</div><div>NLP0014I 27 INFEAS 0.022268486 32 0.074</div><div>NLP0014I 28 OPT 0.0041219556 6 0.012</div><div>NLP0014I 29 FAILED 1.241151 3000 7.391</div>
<div>NLP0014I 30 FAILED 0.018211754 3000 7.548</div><div>NLP0014I 31 OPT 0.0041219556 803 1.956</div><div>NLP0014I 32 FAILED -0.15280958 3000 7.369</div><div>
NLP0014I 33 OPT 0.0041219545 9 0.03</div><div>NLP0014I 34 FAILED -0.07020253 3000 7.219</div><div>NLP0014I 35 OPT 0.0041219549 7 0.022</div><div>NLP0014I 36 FAILED -0.069945526 3000 7.181</div>
<div>NLP0014I 37 OPT 0.0041219552 11 0.038</div><div>NLP0014I 38 FAILED -0.070313109 3000 7.356</div><div>NLP0014I 39 OPT 0.0041219556 14 0.031</div><div>
NLP0014I 40 FAILED -0.070260101 3000 7.076</div><div>NLP0012I</div><div> Num Status Obj It time Location</div><div>NLP0014I 41 OPT 0.0041219556 7 0.016</div>
<div>NLP0014I 42 FAILED -0.070746826 3000 7.126</div><div>NLP0014I 43 OPT 0.0041219556 6 0.013</div><div>NLP0014I 44 FAILED -0.070402666 3000 7.196</div><div>
NLP0014I 45 OPT 0.0041219556 6 0.013</div><div>NLP0014I 46 FAILED -0.070522355 3000 7.377</div><div>NLP0014I 47 OPT 0.0041219556 6 0.013</div><div>NLP0014I 48 FAILED -0.069211894 3000 7.122</div>
<div>NLP0014I 49 OPT 0.0041219556 6 0.012</div><div>NLP0014I 50 FAILED -0.053808856 3000 6.91</div><div>NLP0014I 51 OPT 0.0041219556 6 0.013</div><div>
NLP0014I 52 INFEAS 0.016728388 36 0.086</div><div>NLP0014I 53 OPT 0.0041219556 6 0.013</div><div>NLP0014I 54 FAILED 1.2291456 3000 7.679</div><div>NLP0014I 55 FAILED 0.0045429683 3000 7.632</div>
<div>NLP0014I 56 OPT 0.0041219556 6 0.013</div><div>NLP0014I 57 INFEAS 0.010787243 32 0.075</div><div>NLP0014I 58 OPT 0.0041219556 6 0.013</div><div>
NLP0014I 59 FAILED 1.1645369 3000 8.174</div><div>NLP0014I 60 FAILED 0.0063708004 3000 7.581</div><div>NLP0012I</div><div> Num Status Obj It time Location</div>
<div>NLP0014I 61 OPT 0.0041219492 20 0.062</div><div>NLP0014I 62 INFEAS 0.0046434659 38 0.089</div><div>NLP0014I 63 OPT 0.0041219492 20 0.063</div><div>
NLP0014I 64 INFEAS 0.99998118 703 1.888</div><div>NLP0014I 65 FAILED 1.2612585 3000 8.095</div><div>NLP0014I 66 FAILED 1.2456221 3000 7.746</div><div>Cbc0001I Search completed - best objective 1e+050, took 3038 iterations and 0 nodes (299.17 seconds)</div>
<div>Cbc0032I Strong branching done 29 times (116699 iterations), fathomed 0 nodes and fixed 5 variables</div><div>Cbc0035I Maximum depth 0, 0 variables fixed on reduced cost</div><div>NLP0014I 67 FAILED -0.14257739 3000 7.17</div>
<div><br></div><div> "Finished"</div><div><br></div><div>bonmin: Infeasible problem</div></div>