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Transport11.java
1package com.gams.examples.transport;
2
3import java.io.File;
4import java.util.Arrays;
5import java.util.HashMap;
6import java.util.List;
7import java.util.Map;
8import java.util.Vector;
9
10import com.gams.api.GAMSCheckpoint;
11import com.gams.api.GAMSDatabase;
12import com.gams.api.GAMSJob;
13import com.gams.api.GAMSOptions;
14import com.gams.api.GAMSParameter;
15import com.gams.api.GAMSSet;
16import com.gams.api.GAMSVariableRecord;
17import com.gams.api.GAMSWorkspace;
18import com.gams.api.GAMSWorkspaceInfo;
19
24public class Transport11 {
25
26 public static void main(String[] args) {
27 // check workspace info from command line arguments
28 GAMSWorkspaceInfo wsInfo = new GAMSWorkspaceInfo();
29 if (args.length > 0) {
30 wsInfo.setSystemDirectory( args[0] );
31 }
32 // create a directory
33 File workingDirectory = new File(System.getProperty("user.dir"), "Transport11");
34 workingDirectory.mkdir();
35 wsInfo.setWorkingDirectory(workingDirectory.getAbsolutePath());
36 // create a workspace
37 GAMSWorkspace ws = new GAMSWorkspace(wsInfo);
38
39 // Create a save/restart file usually supplied by an application provider
40 // We create it for demonstration purpose
41 CreateSaveRestart( ws, "tbase" );
42
43 // define some data by using Java data structures
44 List<String> plants = Arrays.asList("Seattle", "San-Diego");
45 List<String> markets = Arrays.asList("New-York", "Chicago", "Topeka");
46
47 Map<String, Double> capacity = new HashMap<String, Double>();
48 {
49 capacity.put("Seattle", Double.valueOf(350.0));
50 capacity.put("San-Diego", Double.valueOf(600.0));
51 }
52
53 Map<String, Double> demand = new HashMap<String, Double>();
54 {
55 demand.put("New-York", Double.valueOf(325.0));
56 demand.put("Chicago", Double.valueOf(300.0));
57 demand.put("Topeka", Double.valueOf(275.0));
58 }
59
60 Map<Vector<String>, Double> distance = new HashMap<Vector<String>, Double>();
61 {
62 distance.put( new Vector<String>( Arrays.asList(new String[]{"Seattle", "New-York"}) ), Double.valueOf(2.5));
63 distance.put( new Vector<String>( Arrays.asList(new String[]{"Seattle", "Chicago"}) ), Double.valueOf(1.7));
64 distance.put( new Vector<String>( Arrays.asList(new String[]{"Seattle", "Topeka"}) ), Double.valueOf(1.8));
65 distance.put( new Vector<String>( Arrays.asList(new String[]{"San-Diego", "New-York"}) ), Double.valueOf(2.5));
66 distance.put( new Vector<String>( Arrays.asList(new String[]{"San-Diego", "Chicago"}) ), Double.valueOf(1.8));
67 distance.put( new Vector<String>( Arrays.asList(new String[]{"San-Diego", "Topeka"}) ), Double.valueOf(1.4));
68 }
69
70 ws = new GAMSWorkspace(wsInfo);
71
72 // prepare a GAMSDatabase with data from the Java data structures
73 GAMSDatabase db = ws.addDatabase();
74
75 GAMSSet i = db.addSet("i", 1, "canning plants");
76 for (String p : plants)
77 i.addRecord(p);
78
79 GAMSSet j = db.addSet("j", 1, "markets");
80 for (String m : markets)
81 j.addRecord(m);
82
83 GAMSParameter a = db.addParameter("a", "capacity of plant i in cases", i);
84 for (String p : plants)
85 a.addRecord(p).setValue( capacity.get(p) );
86
87 GAMSParameter b = db.addParameter("b", "demand at market j in cases", j);
88 for (String m : markets)
89 b.addRecord(m).setValue( demand.get(m) );
90
91 GAMSParameter d = db.addParameter("d", "distance in thousands of miles", i, j);
92 for(Vector<String> vd : distance.keySet())
93 d.addRecord(vd).setValue( distance.get(vd).doubleValue() );
94
95 GAMSParameter f = db.addParameter("f", "freight in dollars per case per thousand miles");
96 f.addRecord().setValue( 90 );
97
98 // run a job using data from the created GAMSDatabase
99 GAMSCheckpoint cpBase = ws.addCheckpoint("tbase");
100
101 GAMSOptions opt = ws.addOptions();
102 GAMSJob t11 = ws.addJobFromString(model, cpBase);
103 opt.defines("gdxincname", db.getName());
104 opt.setAllModelTypes("xpress");
105 t11.run(opt, db);
106
107 for (GAMSVariableRecord rec : t11.OutDB().getVariable("x"))
108 System.out.println("x(" + rec.getKey(0) + "," + rec.getKey(1) + "): level=" + rec.getLevel() + " marginal=" + rec.getMarginal());
109 }
110
111 static void CreateSaveRestart(GAMSWorkspace ws, String cpFileName) {
112 //GAMSWorkspaceInfo wsInfo = new GAMSWorkspaceInfo();
113 //wsInfo.setWorkingDirectory(workingDirectory);
114 //GAMSWorkspace ws = new GAMSWorkspace(wsInfo);
115
116 GAMSJob j1 = ws.addJobFromString(baseModel);
117 GAMSOptions opt = ws.addOptions();
118
119 opt.setAction( GAMSOptions.EAction.CompileOnly );
120
121 GAMSCheckpoint cp = ws.addCheckpoint(cpFileName);
122 j1.run(opt, cp);
123
124 opt.dispose();
125 }
126
127 static String baseModel =
128 "$onempty \n"+
129 " Sets \n"+
130 " i(*) canning plants / / \n"+
131 " j(*) markets / / \n"+
132 " \n"+
133 " Parameters \n"+
134 " a(i) capacity of plant i in cases / / \n"+
135 " b(j) demand at market j in cases / / \n"+
136 " d(i,j) distance in thousands of miles / / \n"+
137 " Scalar f freight in dollars per case per thousand miles /0/; \n"+
138 " \n"+
139 " Parameter c(i,j) transport cost in thousands of dollars per case ;\n"+
140 " \n"+
141 " c(i,j) = f * d(i,j) / 1000 ; \n"+
142 " \n"+
143 " Variables \n"+
144 " x(i,j) shipment quantities in cases \n"+
145 " z total transportation costs in thousands of dollars ; \n"+
146 " \n"+
147 " Positive Variable x ; \n"+
148 " \n"+
149 " Equations \n"+
150 " cost define objective function \n"+
151 " supply(i) observe supply limit at plant i \n"+
152 " demand(j) satisfy demand at market j ; \n"+
153 " \n"+
154 " cost .. z =e= sum((i,j), c(i,j)*x(i,j)) ; \n"+
155 " \n"+
156 " supply(i) .. sum(j, x(i,j)) =l= a(i) ; \n"+
157 " \n"+
158 " demand(j) .. sum(i, x(i,j)) =g= b(j) ; \n"+
159 " \n"+
160 " Model transport /all/ ; \n"+
161 " \n"+
162 " Solve transport using lp minimizing z ; \n"+
163 " \n";
164
165 static String model =
166 "$if not set gdxincname $abort 'no include file name for data file provided' \n"+
167 "$gdxin %gdxincname% \n"+
168 "$onMulti \n"+
169 "$load i j a b d f \n"+
170 "$gdxin \n"+
171 " \n"+
172 "Display x.l, x.m ; \n"+
173 " \n";
174}
com::gams::api::GAMSDatabase::addSet
GAMSSet addSet(String identifier, int dimension)
com::gams::api::GAMSDatabase::addParameter
GAMSParameter addParameter(String identifier, int dimension)
com::gams::api::GAMSDatabase::getVariable
GAMSVariable getVariable(String identifier)
com::gams::api::GAMSJob::OutDB
GAMSDatabase OutDB()
com::gams::api::GAMSOptions::setAction
void setAction(GAMSOptions.EAction x)
com::gams::api::GAMSWorkspaceInfo::setSystemDirectory
void setSystemDirectory(String directory)
com::gams::api::GAMSWorkspaceInfo::setWorkingDirectory
void setWorkingDirectory(String directory)
com::gams::api::GAMSWorkspace::addJobFromString
GAMSJob addJobFromString(String source)
com::gams::api::GAMSWorkspace::addCheckpoint
GAMSCheckpoint addCheckpoint()
com::gams.examples.transport.Transport11
This example shows how to create and use save/restart file.
Definition Transport11.java:24
com::gams
Provides package namespace for Java interface and examples to General Algebraic Model System (GAMS).