[FlopCpp] Availability of warm starts and examples

Mon Mar 18 14:12:59 EDT 2019

Why don't we move the conversation over to the Github issue?

Cheers,

Ted

On Mon, Mar 18, 2019 at 10:17 AM Tim Hultberg <Tim.Hultberg at eumetsat.int>
wrote:

> 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?
>
>
>
> Cheers, Tim
>
>
>
> *From:* Simone Zaccaria [mailto:zaccaria at princeton.edu]
> *Sent:* 18 March 2019 14:47
> *To:* Tim Hultberg <Tim.Hultberg at eumetsat.int>
> *Cc:* Ted Ralphs <ted at lehigh.edu>; mail=flopcpp at list.coin-or.org <
> flopcpp at list.coin-or.org>
> *Subject:* Re: [FlopCpp] Availability of warm starts and examples
>
>
>
> Dear Tim,
>
>
>
> 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?
>
>
>
> Thanks,
>
> Best
>
> --
> Simone Zaccaria
> Postdoctoral Research Associate
> Raphael Lab, Computer Science Department
> Princeton University
> Princeton, NJ 08540
>
>
>
> On Mar 16, 2019, at 12:29 PM, Tim Hultberg <Tim.Hultberg at eumetsat.int>
> wrote:
>
>
>
> Dear Simone,
>
>
>
> Have a look at the FlopCpp
> <https://github.com/coin-or/FlopCpp/tree/master/FlopCpp>/examples
> <https://github.com/coin-or/FlopCpp/tree/master/FlopCpp/examples>/
> *stochbenders.cpp* example, which uses the resolve method of the
> underlying solver interface.
>
>
>
> Cheers, Tim
>
>
> ------------------------------
>
> *From:* FlopCpp <flopcpp-bounces at coin-or.org> on behalf of Ted Ralphs <
> ted at lehigh.edu>
> *Sent:* 15 March 2019 20:58
> *To:* Simone Zaccaria
> *Cc:* mail=flopcpp at list.coin-or.org
> *Subject:* Re: [FlopCpp] Availability of warm starts and examples
>
>
>
> Hi Simone,
>
>
>
> 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:
>
>
>
> https://github.com/coin-or/FlopCpp
> <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=>
>
>
>
> We're in the process of migrating over to Github, but we'll deal with
> issues there going forward.
>
>
>
> Cheers,
>
>
>
> Ted
>
>
>
> On Fri, Mar 15, 2019 at 2:52 PM Simone Zaccaria <zaccaria at princeton.edu>
> wrote:
>
> Dear authors,
>
> 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).
>
> 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:
> 1. Algebraic-like style of programming (e.g. add_constraint(x1 + x2 >= x3))
> 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
> 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.
>
> Thank you,
> Best regards
> --
> Simone Zaccaria
> Postdoctoral Research Associate
> Raphael Lab, Computer Science Department
> Princeton University
> Princeton, NJ 08540
>
>
> _______________________________________________
> FlopCpp mailing list
> FlopCpp at list.coin-or.org
>
> https://urldefense.proofpoint.com/v2/url?u=https-3A__list.coin-2Dor.org_mailman_listinfo_flopcpp&d=DwICAg&c=Ngd-ta5yRYsqeUsEDgxhcqsYYY1Xs5ogLxWPA_2Wlc4&r=rnUB298ByR5BGgo6vv2b6g&m=rgmzeitoi_JLsKZVuhLlfU_msN8xdTJ2mHeJJLFQb9E&s=l0NSF6svBO1Aeo-BxsRKiGQMcs6-mZwgtLGmXeqKGWk&e=
>
>
>
>
> --
>
> Dr. Ted Ralphs
> Professor, Industrial and Systems Engineering
> Lehigh University
> (610) 628-1280
> ted 'at' lehigh 'dot' edu
> coral.ie.lehigh.edu/~ted
> <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=>
>
>
> Any email message from EUMETSAT is sent in good faith but shall neither be
> binding nor construed as constituting a commitment by EUMETSAT, except
> where provided for in a written agreement or contract or if explicitly
> stated in the email. Please note that any views or opinions presented in
> this email are solely those of the sender and do not necessarily represent
> those of EUMETSAT. This message and any attachments are intended for the
> sole use of the addressee(s) and may contain confidential and privileged
> information. Any unauthorised use, disclosure, dissemination or
> distribution (in whole or in part) of its contents is not permitted. If you
> received this message in error, please notify the sender and delete it from
> your system.
>
>
>
> Any email message from EUMETSAT is sent in good faith but shall neither be
> binding nor construed as constituting a commitment by EUMETSAT, except
> where provided for in a written agreement or contract or if explicitly
> stated in the email. Please note that any views or opinions presented in
> this email are solely those of the sender and do not necessarily represent
> those of EUMETSAT. This message and any attachments are intended for the
> sole use of the addressee(s) and may contain confidential and privileged
> information. Any unauthorised use, disclosure, dissemination or
> distribution (in whole or in part) of its contents is not permitted. If you
> received this message in error, please notify the sender and delete it from
> your system.
>

-- 
Dr. Ted Ralphs
Professor, Industrial and Systems Engineering
Lehigh University
(610) 628-1280
ted 'at' lehigh 'dot' edu
coral.ie.lehigh.edu/~ted
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://list.coin-or.org/pipermail/flopcpp/attachments/20190318/42edb932/attachment.html>