$title  Use GdxDump NoData on Transportation Problem (GDXDUMP1,SEQ=504)

$onText
Use GdxDump NoData option to create declarations for some GAMS Symbols

Contributor: M. Bussieck
$offText

$onEcho > t.gms
Sets
     i   canning plants   / seattle, san-diego /
     j   markets          / new-york, chicago, topeka / ;

alias (i,ii);

Parameters

     a(i)  capacity of plant i in cases
       /    seattle     350
            san-diego   600  /

     b(j)  demand at market j in cases
       /    new-york    325
            chicago     300
            topeka      275  / ;

Table d(i,j)  distance in thousands of miles
                  new-york       chicago      topeka
    seattle          2.5           1.7          1.8
    san-diego        2.5           1.8          1.4  ;

Scalar f  '  (freight in dollars per case per thousand miles)' ;

Parameter c(i,j)  transport cost in thousands of dollars per case ;

Positive variables  x(i,j)  shipment quantities in cases ;
$offEcho
$call gams t.gms lo=%gams.lo% gdx=t.gdx
$if errorlevel 1 $abort 'problems with creating data gdx file t.gdx'

$call gdxdump t.gdx nodata > td.gms
$if errorlevel 1 $abort 'problems with gdxdump NoData'

$include td

f = 90;
c(ii,j) = f * d(ii,j) / 1000 ;

Variable z;

Equations
     cost        define objective function
     supply(i)   observe supply limit at plant i
     demand(j)   satisfy demand at market j ;

cost ..        z  =e=  sum((i,j), c(i,j)*x(i,j)) ;

supply(ii) ..   sum(j, x(ii,j))  =l=  a(ii) ;

demand(j) ..   sum(i, x(i,j))  =g=  b(j) ;

Model transport /all/ ;

Solve transport using lp minimizing z ;

Display x.l, x.m ;