transport2.cpp
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26 #include "gams.h"
27 #include <iostream>
28 #include <fstream>
29 
30 using namespace gams;
31 using namespace std;
32 
34 string getDataText()
35 {
36  return "Sets \n"
37  " i canning plants / seattle, san-diego / \n"
38  " j markets / new-york, chicago, topeka / ; \n"
39  "Parameters \n"
40  " \n"
41  " a(i) capacity of plant i in cases \n"
42  " / seattle 350 \n"
43  " san-diego 600 / \n"
44  " \n"
45  " b(j) demand at market j in cases \n"
46  " / new-york 325 \n"
47  " chicago 300 \n"
48  " topeka 275 / ; \n"
49  " \n"
50  "Table d(i,j) distance in thousands of miles \n"
51  " new-york chicago topeka \n"
52  " seattle 2.5 1.7 1.8 \n"
53  " san-diego 2.5 1.8 1.4 ; \n"
54  " \n"
55  "Scalar f freight in dollars per case per thousand miles /90/;\n";
56 }
57 
59 string getModelText()
60 {
61  return "Sets \n"
62  " i canning plants \n"
63  " j markets \n"
64  " \n"
65  "Parameters \n"
66  " a(i) capacity of plant i in cases \n"
67  " b(j) demand at market j in cases \n"
68  " d(i,j) distance in thousands of miles \n"
69  "Scalar f freight in dollars per case per thousand miles; \n"
70  " \n"
71  "$if not set incname $abort 'no include file name for data file provided'\n"
72  "$include %incname% \n"
73  " \n"
74  " Parameter c(i,j) transport cost in thousands of dollars per case ; \n"
75  " \n"
76  " c(i,j) = f * d(i,j) / 1000 ; \n"
77  " \n"
78  " Variables \n"
79  " x(i,j) shipment quantities in cases \n"
80  " z total transportation costs in thousands of dollars ; \n"
81  " \n"
82  " Positive Variable x ; \n"
83  " \n"
84  " Equations \n"
85  " \n"
86  " cost define objective function \n"
87  " supply(i) observe supply limit at plant i \n"
88  " demand(j) satisfy demand at market j ; \n"
89  " \n"
90  " cost .. z =e= sum((i,j), c(i,j)*x(i,j)) ; \n"
91  " \n"
92  " supply(i) .. sum(j, x(i,j)) =l= a(i) ; \n"
93  " \n"
94  " demand(j) .. sum(i, x(i,j)) =g= b(j) ; \n"
95  " \n"
96  " Model transport /all/ ; \n"
97  " \n"
98  " Solve transport using lp minimizing z ; \n"
99  " \n"
100  "Display x.l, x.m ; \n";
101 }
102 
108 int main(int argc, char* argv[])
109 {
110  cout << "---------- Transport 2 --------------" << endl;
111 
112  try {
113  GAMSWorkspaceInfo wsInfo;
114  if (argc > 1)
115  wsInfo.setSystemDirectory(argv[1]);
116  GAMSWorkspace ws(wsInfo);
117 
118  // write an include file containing data with GAMS syntax
119  ofstream tdata(ws.workingDirectory() + cPathSep + "tdata.gms");
120  tdata << getDataText();
121  tdata.close();
122 
123  // run a job using an instance of GAMSOptions that defines the data include file
124  GAMSOptions opt = ws.addOptions();
125  GAMSJob t2 = ws.addJobFromString(getModelText());
126  opt.setDefine("incname", "tdata");
127  t2.run(opt);
128  for (GAMSVariableRecord rec : t2.outDB().getVariable("x"))
129  cout << "x(" << rec.key(0) << "," << rec.key(1) << "):" << " level=" << rec.level() << " marginal="
130  << rec.marginal() << endl;
131 
132  } catch (GAMSException &ex) {
133  cout << "GAMSException occured: " << ex.what() << endl;
134  } catch (exception &ex) {
135  cout << ex.what() << endl;
136  }
137 
138  return 0;
139 }
void setSystemDirectory(std::string systemDir)
GAMSVariable getVariable(const std::string &name)
string getModelText()
Get model as string.
Definition: transport2.cpp:59
GAMSDatabase outDB()
string getDataText()
Get data as string.
Definition: transport2.cpp:34
void setDefine(const std::string &key, const std::string &value)