<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=iso-8859-1"><meta name=Generator content="Microsoft Word 15 (filtered medium)"><style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri",sans-serif;
mso-fareast-language:EN-US;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:#0563C1;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:#954F72;
text-decoration:underline;}
span.E-MailFormatvorlage17
{mso-style-type:personal-compose;
font-family:"Calibri",sans-serif;
color:windowtext;}
.MsoChpDefault
{mso-style-type:export-only;
font-family:"Calibri",sans-serif;
mso-fareast-language:EN-US;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:70.85pt 70.85pt 2.0cm 70.85pt;}
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=DE link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoNormal>Dear SCIP users, <o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><span lang=EN-US>I would like to read in an MPS-file, detect a possible arrowhead structure via dec_hcgpartition.cpp and then write the MPS-file with the new structure. I was able to read in an MPS-file and solve it, but I get a segmentation fault while writing the MPS-file (see [2] for the code). When running in debugger I get error [1].<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>Could you point out what I am doing wrong while trying to write the MPS-file? <br>Additionally, why is vars two-dimensional? Should this not be just a long array with all the variables in it? How do I print the solution in a correct way? A nested loop over i and j does not honor the sparse structure of the constraint matrix A. <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>Finally, is there an example on how to use the structure detection of GCG? <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>Thank you very much for your help! <br><br>Best, <br>Henrik<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>[1]<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>Program received signal SIGSEGV, Segmentation fault.<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>SCIPreaderGetData (reader=reader@entry=0x0)<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> at /home/henrik/Code/scipoptsuite-6.0.1/scip/src/scip/reader.c:488<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>488 return reader->readerdata;<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>[2]<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>// Derived from Queens example by Cornelius Schwarz<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>#include <scip/scip.h><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>#include <scip/scipdefplugins.h><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>#include "scip_exception.hpp"<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>#include <iostream><o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>using namespace std;<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US>/** main function **/<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>int<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>main()<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>{<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> // Define scip pointer and filename<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> SCIP* scip;<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> SCIP_READER* reader;<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> const char* filename="/home/henrik/JSC/FINE_exampleMpsFiles/toy.MPS";<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> cout << filename << endl;<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> SCIP_RESULT* result;<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> result = new SCIP_RESULT[3];<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US> // Create scip environment<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> SCIP_CALL_EXC(SCIPcreate(& scip));<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US> // Load desired plugins<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> SCIP_CALL_EXC(SCIPincludeDefaultPlugins(scip));<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US> // disable scip output to stdout<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> SCIPmessagehdlrSetQuiet(SCIPgetMessagehdlr(scip), TRUE);<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US> // Read in *.MPS file<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> SCIPreadMps(scip, reader, filename, result, <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> </span>NULL,NULL,<o:p></o:p></p><p class=MsoNormal> NULL,NULL, <o:p></o:p></p><p class=MsoNormal> NULL,NULL<o:p></o:p></p><p class=MsoNormal> <span lang=EN-US>);<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> // Solve<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> SCIP_CALL_EXC(SCIPsolve(scip));<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US> // Display solution<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> SCIP_VAR** vars;<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> vars = SCIPgetVars(scip);<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> SCIP_SOL* sol;<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> sol = SCIPgetBestSol(scip);<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US> for (int i=0; i<3; ++i)<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> for (int j=0; j<3; ++j)<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> {<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> cout << "Solution: " << SCIPgetSolVal(scip, sol, &vars[i][j]) << endl;<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> }<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US> int nvars = SCIPgetNVars(scip); <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> int nbinvars = SCIPgetNBinVars(scip);<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> int nintvars = SCIPgetNIntVars(scip);<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> int nimplvars = SCIPgetNImplVars(scip); <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> int ncontvars = SCIPgetNContVars(scip);<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> SCIP_Real objscale = 1.0;<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> SCIP_Real objoffset = 0.0;<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> SCIP_VAR** fixedvars = SCIPgetFixedVars(scip);<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> int nfixedvars = SCIPgetNFixedVars(scip);<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> SCIP_CONS** conss = SCIPgetConss(scip);<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> int nconss = SCIPgetNConss(scip); <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> const char* name="Toy"; <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US> SCIPwriteMps(scip, reader, NULL, name, FALSE, SCIP_OBJSENSE_MINIMIZE,<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> objscale, objoffset, vars, nvars, nbinvars, nintvars,<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> nimplvars, ncontvars, fixedvars, nfixedvars, conss,<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> nconss, result<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US> );<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US> return EXIT_SUCCESS;<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US>}<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-family:"Courier New";mso-fareast-language:DE'>-- <o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-family:"Courier New";mso-fareast-language:DE'>Dipl.-Math. Henrik Büsing<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-family:"Courier New";mso-fareast-language:DE'>Jülich Supercomputing Centre<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New";mso-fareast-language:DE'>Institute for Advanced Simulation<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New";mso-fareast-language:DE'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New";mso-fareast-language:DE'>Forschungszentrum Jülich<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New";mso-fareast-language:DE'>Wilhelm-Johnen-Straße<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-family:"Courier New";mso-fareast-language:DE'>52425 Jülich, Germany<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-family:"Courier New";mso-fareast-language:DE'><o:p> </o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-family:"Courier New";mso-fareast-language:DE'>Phone: +49-2461-61-9884<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-family:"Courier New";mso-fareast-language:DE'>Fax: +49-2461-61-6656<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-family:"Courier New";mso-fareast-language:DE'>E-Mail: H.Buesing@fz-juelich.de<o:p></o:p></span></p><p class=MsoNormal><span lang=EN-US style='font-family:"Courier New";mso-fareast-language:DE'>WWW: http://www.fz-juelich.de/ias/jsc<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New";mso-fareast-language:DE'>-------------------------------------------------------------------------------------<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New";mso-fareast-language:DE'>-------------------------------------------------------------------------------------<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New";mso-fareast-language:DE'>Forschungszentrum Juelich GmbH<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New";mso-fareast-language:DE'>52425 Juelich<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New";mso-fareast-language:DE'>Sitz der Gesellschaft: Juelich<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New";mso-fareast-language:DE'>Eingetragen im Handelsregister des Amtsgerichts Dueren Nr. HR B 3498<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New";mso-fareast-language:DE'>Vorsitzender des Aufsichtsrats: MinDir Volker Rieke<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New";mso-fareast-language:DE'>Geschaeftsfuehrung: Prof. Dr.-Ing. Wolfgang Marquardt (Vorsitzender),<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New";mso-fareast-language:DE'>Karsten Beneke (stellv. Vorsitzender), Prof. Dr.-Ing. Harald Bolt,<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New";mso-fareast-language:DE'>Prof. Dr. Sebastian M. Schmidt<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New";mso-fareast-language:DE'>-------------------------------------------------------------------------------------<o:p></o:p></span></p><p class=MsoNormal><span style='font-family:"Courier New";mso-fareast-language:DE'>-------------------------------------------------------------------------------------<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>