I built my first GAMS code, but I don't know how to transfer the results from the lst file to Python in order to process. If anyone could help with the issue I would be very grateful. For example, for the transportation problem how can I transfer the total cost and the shipment quantities in a Python project?
$Title A Transportation Problem (TRNSPORT,SEQ=1) $Ontext
This problem finds a least cost shipping schedule that meets requirements at markets and supplies at factories.
Dantzig, G B, Chapter 3.3. In Linear Programming and Extensions. Princeton University Press, Princeton, New Jersey, 1963.
This formulation is described in detail in: Rosenthal, R E, Chapter 2: A GAMS Tutorial. In GAMS: A User's Guide. The Scientific Press, Redwood City, California, 1988.
The line numbers will not match those in the book because of these comments.
$Offtext
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/ ;
Solve transport using lp minimizing z ;
Display x.l, x.m ;