<div dir="ltr">Thanks John.<div><br></div><div>Cbc was what I actually needed.</div><div>I am using the standalone executable of cbc which solves the Binary Integer program that I provide using a .mps file.</div><div>For some instances I get the solution within seconds, but for one of my inputs, it took one day to complete and get an optimal solution. The corresponding stdout logs were like this:</div>
<div><br></div><div><i>"</i></div><div><i>...</i></div><div><i>Problem BIP has 287088 rows, 7346 columns and 509272 elements<br></i></div><div><i>...</i></div><div><i>...</i></div><div><i>...</i></div><div><i><br></i></div>
<div><div><i>Result - Optimal solution found</i></div><div><i><br></i></div><div><i>Objective value: 0.00004017</i></div><div><i>Enumerated nodes: 92760</i></div><div><i>Total iterations: 85136638</i></div>
<div><i>Time (CPU seconds): 85473.77</i></div><div><i>Time (Wallclock seconds): 85683.41</i></div><div><i><br></i></div><div><i>Total time (CPU seconds): 85474.08 (Wallclock seconds): 85683.75</i></div>
<div><i><br></i></div></div><div><i>"</i></div><div>Reason is probably the size of data.</div><div>I realized that there is an option of using multiple threads while running cbc (source: man page of Ubuntu), I tried to use that:</div>
<div><br></div><div><div>$ cbc myFIle.mps solve -threads 6 -solution cbcSoln.txt</div></div><div><br></div><div><i>"<br></i></div><div><i>...</i></div><div><i>threads was changed from 0 to 6<br></i></div><div><i>..</i></div>
<div>"</div><div><br></div><div>It gives confirmation of changing threads number, but I don't see any of my other cores being used, just a single processor at 100%. (I am using Dell Precision T5500 Processor: Intel® Xeon(R) CPU X5675 @ 3.07GHz × 12, Memory: 47.2 GB).</div>
<div>I want to reduce the time it takes for finding the solution. Along with switching off the cuts and preprocess options to save time, can I further change some more parameters so that I can save time and get an optimal solution?</div>
<div><br></div><div>Thanks,</div><div>Sourav</div></div><div class="gmail_extra"><br><br><div class="gmail_quote">On Tue, May 20, 2014 at 7:08 PM, John Forrest <span dir="ltr"><<a href="mailto:john.forrest@fastercoin.com" target="_blank">john.forrest@fastercoin.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div text="#000000" bgcolor="#FFFFFF">
<div>Sourav,<br>
<br>
1. -maximize is just a flag - you should follow it with
-dualsimplex or similar.<br>
2. Clp does not solve integer problems - Cbc does so download
that.<br>
<br>
John Forrest<div><div class="h5"><br>
On 20/05/14 10:42, Sourav Garg wrote:<br>
</div></div></div>
<blockquote type="cite"><div><div class="h5">
<div dir="ltr">
<div>
<div>
<div>
<div>
<div>
<div>
<div>
<div>
<div>
<div>
<div>
<div>
<div>
<div>Hello,<br>
<br>
</div>
I am using Clp1.15.6 on an Ubuntu
12.04 machine.<br>
</div>
I have compiled and installed the
executable as mentioned in the readme
install notes, which went successful.<br>
</div>
<br>
1. I have been trying some linear programs
using the Clp executable with a mps file.
It gives me right solution for a
minimization problem (which is the default
direction of optimisation), but it doesn't
give me correct solutions for maximisation
problems.<br>
</div>
<br>
For maximisation, I use it as follows:<br>
</div>
./clp ./my.mps -maximize -solution solFile<br>
</div>
<br>
What I get in the file is:<br>
</div>
status unknown<br>
</div>
objective value 0<br>
</div>
columns val 0 as well..<br>
<br>
</div>
2. Apart from this, I have a Binary Integer Program
problem, for minimisation, in which I pass all the
bounds as BV in the mps file.<br>
</div>
But in the solution I get floating point values for the
non zero columns instead of getting the value of 1. I
wanted to know if Binary Integer Programming is supported
with the library?<br>
<br>
</div>
Thanks,<br>
</div>
Sourav<br>
</div>
<div>
<div>
<div><br>
</div>
</div>
</div>
</div>
<br>
<fieldset></fieldset>
<br>
</div></div><pre>_______________________________________________
Clp mailing list
<a href="mailto:Clp@list.coin-or.org" target="_blank">Clp@list.coin-or.org</a>
<a href="http://list.coin-or.org/mailman/listinfo/clp" target="_blank">http://list.coin-or.org/mailman/listinfo/clp</a>
</pre>
</blockquote>
<br>
</div>
<br>_______________________________________________<br>
Clp mailing list<br>
<a href="mailto:Clp@list.coin-or.org">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><br>
<br></blockquote></div><br></div>