<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<meta name="Generator" content="Microsoft Word 14 (filtered medium)">
<style><!--
/* Font Definitions */
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
span.EmailStyle17
{mso-style-type:personal-reply;
font-family:"Calibri","sans-serif";
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri","sans-serif";}
@page WordSection1
{size:8.5in 11.0in;
margin:56.7pt 42.5pt 56.7pt 85.05pt;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang="EN-US" link="blue" vlink="purple">
<div class="WordSection1">
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">I’ve just begun to look into Pyomo, and I asked their user-group if it directly connect to CBC (and I presume CLP) (<a href="https://groups.google.com/forum/#!topic/pyomo-forum/60G-vDRSLbA">https://groups.google.com/forum/#!topic/pyomo-forum/60G-vDRSLbA</a>).
The answer from Gabriel Hackebeil is that Pyomo uses file-based I/O, so I imagine it does not solve support the “hundreds of gigabytes” issue that Matt has.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> clp-bounces@list.coin-or.org [mailto:clp-bounces@list.coin-or.org]
<b>On Behalf Of </b>Matthew Gidden<br>
<b>Sent:</b> Wednesday, July 08, 2015 12:00 PM<br>
<b>To:</b> Matt Bromberg<br>
<b>Cc:</b> clp@list.coin-or.org<br>
<b>Subject:</b> Re: [Clp] Dense LP Problem Interface<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<div>
<p class="MsoNormal">Hi Matt,<o:p></o:p></p>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal">Have you checked out <a href="https://software.sandia.gov/trac/pyomo">
Pyomo</a>? It's a python mathematical programming interface from Sandia that can call a number of solvers (namely, COIN CBC for this case). I admit that I haven't used it much myself (yet), but it looks promising and seems to have some overlap with the COIN-OR
community as well.<o:p></o:p></p>
</div>
</div>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
<div>
<p class="MsoNormal">On Wed, Jul 8, 2015 at 10:53 AM, Matt Bromberg <<a href="mailto:mattcbro@earthlink.net" target="_blank">mattcbro@earthlink.net</a>> wrote:<o:p></o:p></p>
<p class="MsoNormal">I have yet to see a simple way to use CBC or CLP using raw binary data. In particular I have a large problem with 40K constraints 10K variables or so.<br>
That's about 3Gbytes of raw doubles. It expands to an unwieldy size using any of the text base input formats. (hundreds of gigabytes).<br>
<br>
I can get that data into a python numpy array but it does not appear to be easy to dump that raw array into CLP. Unfortunately cylp doesn't support the latest API.<br>
I would roll my own python interface but there is literally no documentation I can find online for the C interface to something like CoinMP.<br>
<br>
All the other interfaces appear to be useless for my purposes. Pulp is rather arcane and there is no obvious way to pull the data back into python.<br>
<br>
I am in somewhat disbelief that I can't do this:<br>
[xopt,fmin] = linprog(c, Acon, rhsvec) ;<br>
<br>
to solve min c' * x given Acon * x <= rhsvec .<br>
<br>
The above is the one line matlab interface to linprog. There should be something similar in Python in support of CLP using it's primary matrix array interface, numpy/ndarrays.<br>
Even my cylp solution takes 10 lines of python code to do this, plus half a day of parsing documentation. It's just unfortunate that it segfaults on the larger problems.<br>
<br>
If anyone has a good way to do this in Python or C, with an example I'd love to see it. For now I have to move on to other solvers.<br>
_______________________________________________<br>
Clp mailing list<br>
<a href="mailto:Clp@list.coin-or.org" target="_blank">Clp@list.coin-or.org</a><br>
<a href="http://list.coin-or.org/mailman/listinfo/clp" target="_blank">http://list.coin-or.org/mailman/listinfo/clp</a><o:p></o:p></p>
</div>
<p class="MsoNormal"><br>
<br clear="all">
<o:p></o:p></p>
<div>
<p class="MsoNormal"><o:p> </o:p></p>
</div>
<p class="MsoNormal">-- <o:p></o:p></p>
<div>
<div>
<div>
<div>
<p class="MsoNormal">Matthew Gidden, Ph.D.<br>
Postdoctoral Associate, Nuclear Engineering<o:p></o:p></p>
<div>
<p class="MsoNormal">The University of Wisconsin -- Madison<br>
Ph. 225.892.3192<o:p></o:p></p>
</div>
</div>
</div>
</div>
</div>
</div>
</div>
<br>
<hr>
<font face="Arial" color="Gray" size="1">This e-mail and any attachments may be confidential or legally privileged. If you received this message in error or are not the intended recipient, you should destroy the e-mail message and any attachments or copies,
and you are prohibited from retaining, distributing, disclosing or using any information contained herein. Please inform us of the erroneous delivery by return e-mail. Thank you for your cooperation.<br>
</font>
</body>
</html>