Description

The model writes an AWK script on the fly to process the input file
format defined by the maintainers of the QAPLib. More input instances
are available from

https://qaplib.mgi.polymtl.ca/

Small Model of Type : MIQCP

Category : GAMS Model library

Main file : awkqap.gms   includes :  tai7a.inc

$title Input file generation with AWK for the Quadratic Assignment Problem (AWKQAP,SEQ=296)

$onText
The model writes an AWK script on the fly to process the input file
format defined by the maintainers of the QAPLib. More input instances
are available from

https://qaplib.mgi.polymtl.ca/


Burkard, R E, Karisch, S E, and Rendl, F, QAPLIB - A Quadratic Assignment
Problem Library. Journal of Global Optimization 10 (1997), 391-403.

Keywords: mixed integer quadratic constraint programming, quadratic assignment problem,
          QAPLib, awk script
$offText

$set fn tai7a.inc
$if not exist %fn% $abort %fn% ist not present

$echoN "$setGlobal n " > %gams.scrdir%n.%gams.scrext%
$call head -n1 %fn%   >> "%gams.scrdir%n.%gams.scrext%"
$include %gams.scrdir%n.%gams.scrext%

$onEcho > %gams.scrdir%awkscript.%gams.scrext%
BEGIN { print "$onDelim" }
NF == 0 && cnter ==  0 { print "Table d(i,j)";
                         for (i=0; i <= %n%; i++) printf i " "; print }
NF == 0 && cnter == %n% { adj=%n%; print ";"; print "Table f(i,j)";
                          for (i=0; i <= %n%; i++) printf i " "; print }
NF == %n% { cnter++; print cnter-adj, $0; }
END { print ";"; print "$offDelim"; }
$offEcho
$call awk -f "%gams.scrdir%awkscript.%gams.scrext%" %fn% > "%gams.scrdir%data.%gams.scrext%"

Set i / 1*%n% /;

Alias (i,j,k,l);

$include %gams.scrdir%data.%gams.scrext%

* Let's do a trivial MIQCP model
Binary Variable x(i,j);

Variable z;

Equation defobj, assign1(i), assign2(j);

defobj..     z =e= sum((i,j,k,l)$(d(i,j)*f(k,l)), x(i,k)*d(i,j)*f(k,l)*x(j,l));

assign1(i).. sum(j,x(i,j)) =e= 1;

assign2(j).. sum(i,x(i,j)) =e= 1;

Model qap / all /;

* Starting Point
x.l(i,j) = 1/sqr(card(i));

option optCr = 0, optCa = 0.99;

solve qap minimizing z using miqcp;