$title Testing put_utility solver (PUT12,SEQ=776)

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The put_utility solver allows to select a solver by name
during execution type. One can specify the model type or
use '*' to set the solver for all suitable model types

Contributor: Michael Bussieck, August 2018
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Set
   i 'canning plants' / seattle,  san-diego /
   j 'markets'        / new-york, chicago, topeka /;

Parameter
   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' / 90 /;

Parameter c(i,j) 'transport cost in thousands of dollars per case';
c(i,j) = f*d(i,j)/1000;

Variable
   x(i,j) 'shipment quantities in cases'
   z      'total transportation costs in thousands of dollars';

Positive Variable x;

Equation
   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(i).. sum(j, x(i,j)) =l= a(i);

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

Model transport / all /;

Scalar cplexID, soplexID;

put_utility 'solver' / 'lp' / 'cplex';
solve transport using lp minimizing z;
cplexID = transport.sysIdent;

put_utility 'solver' / 'lp' / 'soplex';
solve transport using lp minimizing z;
soplexID = transport.sysIdent;

abort$(cplexID=soplexID) 'used the same solver', cplexID, soplexID;

put_utility 'solver' / '*' / 'cplex';
solve transport using rmip minimizing z;
cplexID = transport.sysIdent;

put_utility 'solver' / '*' / 'soplex';
solve transport using rmip minimizing z;
soplexID = transport.sysIdent;

abort$(cplexID=soplexID) 'used the same solver with model type=*', cplexID, soplexID;;