<div dir="ltr">Hi again, <div><br></div><div>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:</div>
<div><br></div><div><a href="https://docs.google.com/file/d/0B4Rt5z2PACNndUZUc184dVBxQVU/edit?usp=sharing">https://docs.google.com/file/d/0B4Rt5z2PACNndUZUc184dVBxQVU/edit?usp=sharing</a><br></div><div><br></div><div>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. </div>
<div><br></div><div>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:</div><div><br></div><div>--------------<br></div><div>
<div>Presolving Time: 4.20</div><div>Quadratic constraint handler does not have LAPACK for eigenvalue computation. Will assume that matrices (with size > 2x2) are indefinite.</div><div><br></div><div> time | node | left |LP iter|LP it/n| mem |mdpt |frac |vars |cons |cols |rows |cuts |confs|strbr| dualbound | primalbound | gap</div>
<div> 6.5s| 1 | 0 | 1111 | - | 21M| 0 | 6 |4268 |3217 |4268 |3196 | 0 | 15 | 0 | 0.000000e+00 | -- | Inf</div><div> 6.7s| 1 | 0 | 1563 | - | 21M| 0 | 6 |4268 |3217 |4268 |3196 | 0 | 15 | 0 | 0.000000e+00 | -- | Inf</div>
<div> 6.8s| 1 | 0 | 1575 | - | 21M| 0 | 6 |4268 |3217 |4268 |3207 | 11 | 15 | 0 | 0.000000e+00 | -- | Inf</div></div><div>--------------<br></div><div><br></div><div>While NEOS output file looks like this:</div>
<div><br></div><div>--------------</div><div><pre style="color:rgb(0,0,0)">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 visit <a href="http://projects.coin-or.org/Ipopt">http://projects.coin-or.org/Ipopt</a>
******************************************************************************
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%</pre></div><div>--------------<br></div><div><br></div><div>Do you know why I cannot reproduce such results? Might I be missing something, like the IPOPT nonlinear solver?</div>
<div><br></div><div>Thank you very much,</div><div>Cristiano</div><div><br></div><div><br></div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Sat, Sep 28, 2013 at 4:30 PM, Cristiano Arbex <span dir="ltr"><<a href="mailto:crisarbex@gmail.com" target="_blank">crisarbex@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Thank you very much, Stefan, that was very helpful.</div><div class="HOEnZb"><div class="h5"><div class="gmail_extra">
<br><br><div class="gmail_quote">On Sat, Sep 28, 2013 at 2:06 PM, Stefan Vigerske <span dir="ltr"><<a href="mailto:stefan@math.hu-berlin.de" target="_blank">stefan@math.hu-berlin.de</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Hi,<br>
<br>
what is not supported so far is to set SCIP options via the AMPL script language.<br>
However, AMPL/SCIP reads by default SCIP options from the file scip.set, if present.<br>
<br>
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.,<br>
./bin/scipampl <a href="http://foo.nl" target="_blank">foo.nl</a> myoptions.set<br>
<br>
Btw, adding "-i" to the command line arguments gives you the SCIP interactive shell.<br>
<br>
Hope that helps,<br>
Stefan<div><div><br>
<br>
<br>
On 09/28/2013 01:55 PM, Cristiano Arbex wrote:<br>
</div></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div>
I am trying to use SCIP with its interface to AMPL, which I installed on<br>
Linux via this following tutorial:<br>
<br>
<a href="http://zverovich.net/2012/08/07/using-scip-with-ampl.html" target="_blank">http://zverovich.net/2012/08/<u></u>07/using-scip-with-ampl.html</a><br>
<br>
<br>
In the tutorial it is said that no SCIP options are currently supported. Do<br>
you know if there is a way to use options with AMPL or if there is an<br>
alternate way to do this, for example, by presenting an options file?<br>
<br>
Thank you very much,<br>
Cristiano<br>
<br>
<br>
<br></div></div>
______________________________<u></u>_________________<br>
Scip mailing list<br>
<a href="mailto:Scip@zib.de" target="_blank">Scip@zib.de</a><br>
<a href="http://listserv.zib.de/mailman/listinfo/scip" target="_blank">http://listserv.zib.de/<u></u>mailman/listinfo/scip</a><br>
<br>
</blockquote>
<br>
</blockquote></div><br></div>
</div></div></blockquote></div><br></div>