rs01.gms : Solving a Transportation Problem using Cplex and Gurobi remote server

Description

```We solve the trnsport model using the Cplex remote server.
through the environment variable CPXRS
```

Small Model of Type : GAMS

Category : GAMS Test library

Main file : rs01.gms

``````\$Title  Solving a Transportation Problem using Cplex remote server (RS01,SEQ=611)
\$Ontext

We solve the trnsport model using the Cplex remote server.
through the environment variable CPXRS

\$Offtext
\$echo computeserver %sysenv.CPXRS% > cplexd.opt

Sets
i   canning plants   / seattle, san-diego /
j   markets          / new-york, chicago, topeka / ;

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  /90/ ;

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

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

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

Positive Variable x ;

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

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

Model transport /all/ ;

transport.optfile=1;

\$ifthen %system.buildcode% == SOX
* On Sparc Solaris the system can't find some shared objects required for the Cplex remote object.
* Hence, we need to set things explictely and make sure the LD_LIBRARY_PATH environment is not
* forgotten when we call the solver.
\$setenv LD_LIBRARY_PATH %gams.sysdir%:%sysenv.LD_LIBRARY_PATH%