<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2//EN">
<HTML>
<HEAD>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=us-ascii">
<META NAME="Generator" CONTENT="MS Exchange Server version 6.0.6618.1">
<TITLE>Symphony Size limitation?</TITLE>
</HEAD>
<BODY>
<!-- Converted from text/rtf format -->
<P><FONT SIZE=2 FACE="Arial">Hi,</FONT>
</P>
<P><FONT SIZE=2 FACE="Arial">I have been using Symphony (5.1.10) successfully, with a GMPL model (GLPK 4.31) on Sun Solaris 5.8. But when I scale up the size of the problem (more integer variables, more constraints) beyond a certain level, Synphony terminates before getting very far, with a core dump (no error message). Are there any inherent size limitations that I need to be aware of? I did try increasing the max_size parameter, but this did not seem to have any effect.</FONT></P>
<P><FONT SIZE=2 FACE="Arial">The problem may be associated with cut generation, but I'm not sure. The last message before the core dump is "2 Gomory cuts added". When running the same model, smaller size, it generates other types of cuts (flow cover, 2-MIR), but no Gomory cuts. So maybe the larger size problem requires the Gomory cuts, and there's a problem with that routine. Or maybe the problem is the problem size itself. There are about 8000 binary variables in the model I'm running, to give an idea of the size.</FONT></P>
<P><FONT SIZE=2 FACE="Arial">Any ideas on how to troubleshoot or work around this issue would be appreciated.</FONT>
</P>
<P><FONT SIZE=2 FACE="Arial">Thanks.</FONT>
</P>
<P><FONT SIZE=2 FACE="Arial">Stu Rundlett</FONT>
</P>
</BODY>
</HTML>