[Scip] SCIP interface with AMPL

[Ambros Gleixner]

Hi Cristiano,

exactly, your installation seems to miss Ipopt.  You have to use "make 
IPOPT=true" when compiling SCIP and provide the link to the build 
directory of your Ipopt installation.

Best regards,

Ambros



Am 30.09.2013 16:55, schrieb Cristiano Arbex:
> Hi again,
>
> I've been using the NEOS server to test SCIP and I've been impressed
> with its speed. I tried solving 36 nonlinear instances and the largest
> one can be downloaded here:
>
> https://docs.google.com/file/d/0B4Rt5z2PACNndUZUc184dVBxQVU/edit?usp=sharing
>
> It takes NEOS SCIP 6 seconds to solve it. I am using the same scip.set
> parameters file that can be found on NEOS. I installed the SCIP
> optimization suite following the steps in the link provided in the first
> message of this thread.
>
> I know my PC is slower than the NEOS server but SCIP on my PC has been
> solving the same instance for 1200s. In the output file I get this message:
>
> --------------
> Presolving Time: 4.20
> Quadratic constraint handler does not have LAPACK for eigenvalue
> computation. Will assume that matrices (with size > 2x2) are indefinite.
>
>   time | node  | left  |LP iter|LP it/n| mem |mdpt |frac |vars |cons
> |cols |rows |cuts |confs|strbr|  dualbound   | primalbound  |  gap
>    6.5s|     1 |     0 |  1111 |     - |  21M|   0 |   6 |4268 |3217
> |4268 |3196 |   0 |  15 |   0 | 0.000000e+00 |      --      |    Inf
>    6.7s|     1 |     0 |  1563 |     - |  21M|   0 |   6 |4268 |3217
> |4268 |3196 |   0 |  15 |   0 | 0.000000e+00 |      --      |    Inf
>    6.8s|     1 |     0 |  1575 |     - |  21M|   0 |   6 |4268 |3217
> |4268 |3207 |  11 |  15 |   0 | 0.000000e+00 |      --      |    Inf
> --------------
>
> While NEOS output file looks like this:
>
> --------------
>
> Presolving Time: 2.54
>
>   time | node  | left  |LP iter|LP it/n| mem |mdpt |frac |vars |cons |cols |rows |cuts |confs|strbr|  dualbound   | primalbound  |  gap
>    3.8s|     1 |     0 |  1060 |     - |  21M|   0 |   6 |4268 |3217 |4268 |3196 |   0 |  15 |   0 | 0.000000e+00 |      --      |    Inf
>
> ******************************************************************************
> This program contains Ipopt, a library for large-scale nonlinear optimization.
>   Ipopt is released as open source code under the Eclipse Public License (EPL).
>           For more information visithttp://projects.coin-or.org/Ipopt
> ******************************************************************************
>
> q 6.2s|     1 |     0 |  1138 |     - |  21M|   0 |   - |4268 |3217 |4268 |3196 |   0 |  15 |   0 | 0.000000e+00 | 0.000000e+00 |   0.00%
>    6.2s|     1 |     0 |  1138 |     - |  21M|   0 |   - |4268 |3217 |4268 |3196 |   0 |  15 |   0 | 0.000000e+00 | 0.000000e+00 |   0.00%
>
> --------------
>
> Do you know why I cannot reproduce such results? Might I be missing
> something, like the IPOPT nonlinear solver?
>
> Thank you very much,
> Cristiano
>
>
>
>
> On Sat, Sep 28, 2013 at 4:30 PM, Cristiano Arbex <crisarbex at gmail.com
> <mailto:crisarbex at gmail.com>> wrote:
>
>     Thank you very much, Stefan, that was very helpful.
>
>
>     On Sat, Sep 28, 2013 at 2:06 PM, Stefan Vigerske
>     <stefan at math.hu-berlin.de <mailto:stefan at math.hu-berlin.de>> wrote:
>
>         Hi,
>
>         what is not supported so far is to set SCIP options via the AMPL
>         script language.
>         However, AMPL/SCIP reads by default SCIP options from the file
>         scip.set, if present.
>
>         Alternatively, one can specify a SCIP settings file as argument
>         to the AMPL/SCIP binary. However, that would require to write
>         out the AMPL model as .nl file first and to run the binary
>         explicitly, e.g.,
>            ./bin/scipampl foo.nl <http://foo.nl> myoptions.set
>
>         Btw, adding "-i" to the command line arguments gives you the
>         SCIP interactive shell.
>
>         Hope that helps,
>         Stefan
>
>
>
>         On 09/28/2013 01:55 PM, Cristiano Arbex wrote:
>
>             I am trying to use SCIP with its interface to AMPL, which I
>             installed on
>             Linux via this following tutorial:
>
>             http://zverovich.net/2012/08/__07/using-scip-with-ampl.html
>             <http://zverovich.net/2012/08/07/using-scip-with-ampl.html>
>
>
>             In the tutorial it is said that no SCIP options are
>             currently supported. Do
>             you know if there is a way to use options with AMPL or if
>             there is an
>             alternate way to do this, for example, by presenting an
>             options file?
>
>             Thank you very much,
>             Cristiano
>
>
>
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-- 
____________________________________________________________
Ambros M. Gleixner
Zuse Institute Berlin - Matheon - Berlin Mathematical School
http://www.zib.de/gleixner