<br><font size=2 face="sans-serif">These are great questions, and their
answers should be used to improve the current websites. </font>
<br><font size=2 face="sans-serif">I'm not a NEOS user but I can answer
two of them.</font>
<br>
<br><font size=2><tt>>Where is the authoritative specification for MPS
format ?</tt></font>
<br><font size=2 face="sans-serif">There is none. The MPS format
standard is not "standard". Different LP solvers handle somethings
differently. </font>
<br><font size=2 face="sans-serif">Here's another reference. http://www.mosek.com/download/doc/html/2/toolbox/manual/node10.html
I use the IBM OSL manual. </font>
<br><font size=2 face="sans-serif"><br>
</font><font size=2><tt>>I am not sure if Clp is attempting to maximize
or minimize the objective.</tt></font>
<br><font size=2 face="sans-serif">The default is minimize. </font>
<br>
<br><font size=2 face="sans-serif">The NEOS-CLP gurus should be able to
help with the other q's,</font>
<br>
<br><font size=2 face="sans-serif">Robin</font>
<br>
<br><font size=2 face="sans-serif">----------------------------------------------------------------------------------<br>
Robin Lougee-Heimer<br>
IBM TJ Watson Research Center<br>
1101 Kitchawan Road, Yorktown Heights, NY 10598<br>
ph: 914-945-3032 fax: 914-945-3434 <br>
robinlh@us.ibm.com<br>
http://www.coin-or.org<br>
<br>
</font>
<br>
<br>
<br>
<table width=100%>
<tr valign=top>
<td width=40%><font size=1 face="sans-serif"><b>Math407 Summer05 <m407s05@u.washington.edu></b>
</font>
<br><font size=1 face="sans-serif">Sent by: coin-lpsolver-bounces@list.coin-or.org</font>
<p><font size=1 face="sans-serif">06/08/2005 02:01 PM</font>
<td width=59%>
<table width=100%>
<tr>
<td>
<div align=right><font size=1 face="sans-serif">To</font></div>
<td valign=top><font size=1 face="sans-serif">coin-lpsolver@list.coin-or.org</font>
<tr>
<td>
<div align=right><font size=1 face="sans-serif">cc</font></div>
<td valign=top>
<tr>
<td>
<div align=right><font size=1 face="sans-serif">Subject</font></div>
<td valign=top><font size=1 face="sans-serif">[Coin-lpsolver] Using Clp
under Neos</font></table>
<br>
<table>
<tr valign=top>
<td>
<td></table>
<br></table>
<br>
<br>
<br><font size=2><tt><br>
Introduction:<br>
=============<br>
<br>
The support people at Neos have suggest that I contact the Clp help <br>
directly for my questions below. I am having some trouble understanding
<br>
the input and output to the Neos Clp solver for a linear programming case.<br>
On the web page<br>
http://www-neos.mcs.anl.gov/neos/solvers/LP:CLP-MPS/<br>
it states "To solve a linear programming problem using MPS as input,
you <br>
need only submit the MPS file". I was able to find something close
to a <br>
specification of this format in the file<br>
http://www.sbsi-sol-optimize.com/manuals/Minos%20Manual.pdf<br>
<br>
Question I:<br>
==========<br>
Where is the authoritative specification for MPS format ?<br>
<br>
Still the Clp examples seem to have other commands in the submitted job.
For<br>
example,<br>
BEGIN.PAR<br>
primalS<br>
sol -<br>
END.PAR<br>
<br>
BEGIN.COMMENT<br>
Solve using primal simplex, and print solution value<br>
END.COMMENT<br>
<br>
It may be that these commands are listed on the web page<br>
http://www-neos.mcs.anl.gov/neos/solvers/LP:CLP-MPS/<br>
but there is no documentation there (or link to documentation) describing
what<br>
the commands do.<br>
<br>
Question II:<br>
============<br>
Where are the specifications for these other commands (output the MPS input<br>
section) and exactly what they do ?<br>
<br>
For example, I am not sure how to get Clp to choose which of the rows <br>
corresponds to the objective . For another example, I am not sure if Clp
<br>
is attempting to maximize or minimize the objective. (These do not seem
to <br>
be part of the MPS input format but perhaps I am wrong in this.)<br>
<br>
Question III:<br>
============<br>
Where are the specifications for the output that Neos e-mails back to and<br>
what it means ?<br>
<br>
For example, what does the following mean:<br>
Optimal objective 0 - 0 iterations time 0.002, Presolve 0.00<br>
Clp: 0 R1
20
0<br>
1 R2
0
0<br>
2 R3
20
0<br>
0 X1
0
1<br>
1 X2
20
0<br>
Clp:<br>
_______________________________________________<br>
Coin-lpsolver mailing list<br>
Coin-lpsolver@list.coin-or.org<br>
http://list.coin-or.org/mailman/listinfo/coin-lpsolver<br>
</tt></font>
<br>