transport3.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 gdxincname $abort 'no include file name for data file provided'\n"
72  "$gdxin %gdxincname% \n"
73  "$load i j a b d f \n"
74  "$gdxin \n"
75  " \n"
76  " Parameter c(i,j) transport cost in thousands of dollars per case ; \n"
77  " \n"
78  " c(i,j) = f * d(i,j) / 1000 ; \n"
79  " \n"
80  " Variables \n"
81  " x(i,j) shipment quantities in cases \n"
82  " z total transportation costs in thousands of dollars ; \n"
83  " \n"
84  " Positive Variable x ; \n"
85  " \n"
86  " Equations \n"
87  " \n"
88  " cost define objective function \n"
89  " supply(i) observe supply limit at plant i \n"
90  " demand(j) satisfy demand at market j ; \n"
91  " \n"
92  " cost .. z =e= sum((i,j), c(i,j)*x(i,j)) ; \n"
93  " \n"
94  " supply(i) .. sum(j, x(i,j)) =l= a(i) ; \n"
95  " \n"
96  " demand(j) .. sum(i, x(i,j)) =g= b(j) ; \n"
97  " \n"
98  " Model transport /all/ ; \n"
99  " \n"
100  " Solve transport using lp minimizing z ; \n"
101  " \n"
102  "Display x.l, x.m ; \n";
103 }
104 
112 int main(int argc, char* argv[])
113 {
114  cout << "---------- Transport 3 --------------" << endl;
115 
116  try {
117  GAMSWorkspaceInfo wsInfo;
118  if (argc > 1)
119  wsInfo.setSystemDirectory(argv[1]);
120  GAMSWorkspace ws(wsInfo);
121 
122  // data from a string with GAMS syntax with explicit export to GDX file
123  GAMSJob t3 = ws.addJobFromString(getDataText());
124  t3.run();
125  //TODO: change doExport to export?
126  t3.outDB().doExport(ws.workingDirectory() + cPathSep + "tdata.gdx");
127 
128  // run a job using an instance of GAMSOptions that defines the data include file
129  t3 = ws.addJobFromString(getModelText());
130  GAMSOptions opt = ws.addOptions();
131  opt.setDefine("gdxincname", "tdata");
132  opt.setAllModelTypes("xpress");
133  t3.run(opt);
134  for (GAMSVariableRecord rec : t3.outDB().getVariable("x"))
135  cout << "x(" << rec.key(0) << "," << rec.key(1) << "):" << " level=" << rec.level() << " marginal="
136  << rec.marginal() << endl;
137 
138  // same but with implicit database communication
139  GAMSJob t3a = ws.addJobFromString(getDataText());
140  GAMSJob t3b = ws.addJobFromString(getModelText());
141  t3a.run();
142  opt.setDefine("gdxincname", t3a.outDB().name());
143 
144  t3b.run(opt, t3a.outDB());
145  for (GAMSVariableRecord rec : t3.outDB().getVariable("x"))
146  cout << "x(" << rec.key(0) << "," << rec.key(1) << "):" << " level=" << rec.level() << " marginal="
147  << rec.marginal() << endl;
148 
149  } catch (GAMSException &ex) {
150  cout << "GAMSException occured: " << ex.what() << endl;
151  } catch (exception &ex) {
152  cout << ex.what() << endl;
153  }
154 
155  return 0;
156 }
string getDataText()
Get data as string.
Definition: transport3.cpp:34
void setSystemDirectory(std::string systemDir)
GAMSVariable getVariable(const std::string &name)
void setAllModelTypes(const std::string &solver)
GAMSDatabase outDB()
void doExport(const std::string &filePath="")
void setDefine(const std::string &key, const std::string &value)
string getModelText()
Get model as string.
Definition: transport3.cpp:59
std::string name()