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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">No, you are right, in this example the initial solution comes from a previous solve. But you are able to access the warm start methods
of the OSISolverInterface directly with the “pointer syntax” like for resolve. Before looking further into it, I can’t say if that would be sufficient for you or whether some additional support from the modelling layer is needed (or convenient) – maybe Ted
can more about that?<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D;mso-fareast-language:EN-US">Cheers, Tim<o:p></o:p></span></p>
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<p class="MsoNormal"><b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif"> Simone Zaccaria [mailto:zaccaria@princeton.edu]
<br>
<b>Sent:</b> 18 March 2019 14:47<br>
<b>To:</b> Tim Hultberg <Tim.Hultberg@eumetsat.int><br>
<b>Cc:</b> Ted Ralphs <ted@lehigh.edu>; mail=flopcpp@list.coin-or.org <flopcpp@list.coin-or.org><br>
<b>Subject:</b> Re: [FlopCpp] Availability of warm starts and examples<o:p></o:p></span></p>
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<p class="MsoNormal">Dear Tim,<o:p></o:p></p>
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<p class="MsoNormal">Thank you very much for the reference! Unfortunately I am not sure from that example where the initial feasible solution is specified; could you help me with this?<o:p></o:p></p>
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<p class="MsoNormal">Thanks,<o:p></o:p></p>
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<p class="MsoNormal">Best<o:p></o:p></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Helvetica",sans-serif;color:black">--<br>
Simone Zaccaria<br>
Postdoctoral Research Associate<br>
Raphael Lab, Computer Science Department<br>
Princeton University<br>
Princeton, NJ 08540<o:p></o:p></span></p>
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<p class="MsoNormal">On Mar 16, 2019, at 12:29 PM, Tim Hultberg <<a href="mailto:Tim.Hultberg@eumetsat.int">Tim.Hultberg@eumetsat.int</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal" style="background:white"><span style="font-family:"Calibri",sans-serif">Dear Simone,<o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-family:"Calibri",sans-serif">Have a look at the<span class="js-path-segment"><a href="https://github.com/coin-or/FlopCpp/tree/master/FlopCpp"> FlopCpp</a></span><span class="separator">/</span><span class="js-path-segment"><a href="https://github.com/coin-or/FlopCpp/tree/master/FlopCpp/examples">examples</a></span><span class="separator">/</span><strong><span style="font-family:"Calibri",sans-serif">stochbenders.cpp</span></strong><span class="apple-converted-space"><b> </b></span><span class="final-path">example,
which uses the resolve method of the underlying solver interface.</span><o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-family:"Calibri",sans-serif"><o:p> </o:p></span></p>
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<p class="MsoNormal" style="background:white"><span class="final-path"><span style="font-family:"Calibri",sans-serif">Cheers, Tim</span></span><span style="font-family:"Calibri",sans-serif"><o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#212121">From:</span></b><span class="apple-converted-space"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#212121"> </span></span><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#212121">FlopCpp
<<a href="mailto:flopcpp-bounces@coin-or.org">flopcpp-bounces@coin-or.org</a>> on behalf of Ted Ralphs <<a href="mailto:ted@lehigh.edu">ted@lehigh.edu</a>><br>
<b>Sent:</b><span class="apple-converted-space"> </span>15 March 2019 20:58<br>
<b>To:</b><span class="apple-converted-space"> </span>Simone Zaccaria<br>
<b>Cc:</b><span class="apple-converted-space"> </span><a href="mailto:mail=flopcpp@list.coin-or.org">mail=flopcpp@list.coin-or.org</a><br>
<b>Subject:</b><span class="apple-converted-space"> </span>Re: [FlopCpp] Availability of warm starts and examples</span><span style="font-family:"Calibri",sans-serif;color:#212121"><o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-family:"Calibri",sans-serif;color:#212121"> <o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-family:"Calibri",sans-serif;color:#212121">Hi Simone,<o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-family:"Calibri",sans-serif;color:#212121">I'm the nominal maintainer of FlopC++, although I did not write it and haven't used it extensively. The original I sort of inherited maintenance of it
by default and have been fixing things here and there. As far as I know, FlopC++ does not support warm-starting, but I guess it shouldn't be very difficult to add. I can try to take a look, but to keep track of your request, could you open an issue on the
GitHub page for the project:<o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-family:"Calibri",sans-serif;color:#212121"><o:p> </o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-family:"Calibri",sans-serif;color:#212121"><a href="https://urldefense.proofpoint.com/v2/url?u=https-3A__github.com_coin-2Dor_FlopCpp&d=DwMFaQ&c=Ngd-ta5yRYsqeUsEDgxhcqsYYY1Xs5ogLxWPA_2Wlc4&r=Z_vAP52Ad0q2k_P9g-qnFxc4msjNuX2kAmjL74eSbEQ&m=Adu16uhNYXoP-c1Hhdew0-jLPJhCAzjWLSYZVeRJTxI&s=r1Ar5G9x_MmFnAFodrCIPGmypLsOlzVBiLYPLIiywkw&e=">https://github.com/coin-or/FlopCpp</a><o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-family:"Calibri",sans-serif;color:#212121">We're in the process of migrating over to Github, but we'll deal with issues there going forward.<o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-family:"Calibri",sans-serif;color:#212121">Cheers,<o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-family:"Calibri",sans-serif;color:#212121">Ted<o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-family:"Calibri",sans-serif;color:#212121"><o:p> </o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-family:"Calibri",sans-serif;color:#212121">On Fri, Mar 15, 2019 at 2:52 PM Simone Zaccaria <<a href="mailto:zaccaria@princeton.edu">zaccaria@princeton.edu</a>> wrote:<o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-family:"Calibri",sans-serif;color:#212121">Dear authors,<br>
<br>
We have a C++11 program, designed in my research lab at Princeton University, which is currently using Gurobi to solve several MILP formulations in parallel. Now, I need to replace Gurobi with an open-source MILP solver with less restrictive license options,
available also for non-commercial research entities other than universities. I explored several options (GLPK, Coin-OR CBC, SCIP...) but I need to maintain the simplicity of the Gurobi interface (an algebraic like interface).<br>
<br>
As such, I am looking for an open source C++11 modeling language or MILP solver with a C++11 API with the following 2 requirements:<br>
1. Algebraic-like style of programming (e.g. add_constraint(x1 + x2 >= x3))<br>
2. Possibility to specify WARM STARTS (also called, hot starts, MIP starts, or initial solutions) which are basically an initial solution for the variables where to start the optimization<br>
Your FLOC++ package seems a very good option for this, however I was not able to understand whether condition 2. is met. Also I would like to know if there are some available examples.<br>
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Thank you,<br>
Best regards<br>
--<br>
Simone Zaccaria<br>
Postdoctoral Research Associate<br>
Raphael Lab, Computer Science Department<br>
Princeton University<br>
Princeton, NJ 08540<br>
<br>
<br>
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<p class="MsoNormal" style="background:white"><span style="font-family:"Calibri",sans-serif;color:#212121">--<span class="apple-converted-space"> </span><o:p></o:p></span></p>
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<p class="MsoNormal" style="background:white"><span style="font-family:"Calibri",sans-serif;color:#212121">Dr. Ted Ralphs<br>
Professor, Industrial and Systems Engineering<br>
Lehigh University<br>
(610) 628-1280<br>
ted 'at' lehigh 'dot' edu<br>
<a href="https://urldefense.proofpoint.com/v2/url?u=http-3A__coral.ie.lehigh.edu_-7Eted&d=DwMFaQ&c=Ngd-ta5yRYsqeUsEDgxhcqsYYY1Xs5ogLxWPA_2Wlc4&r=Z_vAP52Ad0q2k_P9g-qnFxc4msjNuX2kAmjL74eSbEQ&m=Adu16uhNYXoP-c1Hhdew0-jLPJhCAzjWLSYZVeRJTxI&s=bxc-rGHE_f6b1zXezWk2Aj5aQtRJJS35F1G6TqzNXI8&e=" target="_blank">coral.ie.lehigh.edu/~ted</a><o:p></o:p></span></p>
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