Loading...
Searching...
No Matches
TransportModel.java
1package com.gams.examples.transport;
2
3import java.io.PrintStream;
4
5import com.gams.api.GAMSCheckpoint;
6import com.gams.api.GAMSDatabase;
7import com.gams.api.GAMSException;
8import com.gams.api.GAMSJob;
9import com.gams.api.GAMSOptions;
10import com.gams.api.GAMSParameter;
11import com.gams.api.GAMSSet;
12import com.gams.api.GAMSVariable;
13import com.gams.api.GAMSWorkspace;
14
19public class TransportModel
20{
21 private GAMSSet fi, fj;
22 private GAMSParameter fa, fb, fd, ff;
23 private GAMSVariable fx, fz;
24 private GAMSOptions fopt;
25
26 private GAMSWorkspace fws;
27 private GAMSDatabase fDbIn1, fDbIn2, fDbOut1;
28
29 private GAMSJob job;
30
34 public TransportModel(GAMSWorkspace ws)
35 {
36 fws = ws;
37 fopt = ws.addOptions();
38
39 fDbIn1 = ws.addDatabase("dbIn1");
40 fDbIn2 = ws.addDatabase("dbIn2");
41
42 fopt.defines("dbIn1", "dbIn1");
43 fopt.defines("dbIn2", "dbIn2");
44
45 fopt.setSolveLink( GAMSOptions.ESolveLink.LoadLibrary );
46 fopt.setAllModelTypes( "Cplex" );
47 fopt.defines("dbOut1", "dbOut1");
48
49 fi = fDbIn1.addSet("i", "canning plants");
50 fj = fDbIn1.addSet("j", "markets");
51 fa = fDbIn1.addParameter("a", "capacity of plant i in cases", fi);
52 fb = fDbIn1.addParameter("b", "demand at market j in cases", fj);
53 fd = fDbIn1.addParameter("d", "distance in thousands of miles", new Object[] { fi, fj} );
54 ff = fDbIn2.addParameter("f", "freight in dollars per case per thousand miles");
55
56 job = ws.addJobFromString( this.getModelSource() );
57 }
58
62 public void run(GAMSCheckpoint checkpoint)
63 {
64 this.run(checkpoint, null);
65 }
66
70 public void run(PrintStream output)
71 {
72 this.run(null, output);
73 }
74
79 public void run(GAMSCheckpoint checkpoint, PrintStream output) {
80 if (!fDbIn1.checkDomains())
81 throw new GAMSException("Domain Errors in Database 1");
82 if (!fDbIn2.checkDomains())
83 throw new GAMSException("Domain Errors in Database 2");
84
85 GAMSDatabase[] databases = new GAMSDatabase[] {fDbIn1, fDbIn2 };
86 job.run( fopt, checkpoint, output, false, databases );
87
88 fDbOut1 = fws.addDatabaseFromGDX(fopt.getDefinitionOf("dbOut1") + ".gdx");
89 fx = fDbOut1.getVariable("x");
90 fz = fDbOut1.getVariable("z");
91 }
92
94 public GAMSSet geti() { return fi; }
95
97 public GAMSSet getj() { return fj; }
98
100 public GAMSParameter geta() { return fa; }
101
103 public GAMSParameter getb() { return fb; }
104
106 public GAMSParameter getd() { return fd; }
107
109 public GAMSParameter getf() { return ff; }
110
112 public GAMSVariable getx() { return fx; }
113
115 public GAMSVariable getz() { return fz; }
116
118 public GAMSOptions getopt() { return fopt; }
119
121 public String getModelSource() { return model; }
122
123 private static String model =
124 "Sets \n" +
125 " i canning plants \n" +
126 " j markets \n" +
127 " \n" +
128 " Parameters \n" +
129 " a(i) capacity of plant i in cases \n" +
130 " b(j) demand at market j in cases \n" +
131 " d(i,j) distance in thousands of miles \n" +
132 " Scalar f freight in dollars per case per thousand miles; \n" +
133 " \n" +
134 "$if not set dbIn1 $abort 'no file name for in-database 1 file provided' \n" +
135 "$gdxin %dbIn1% \n" +
136 "$load i j a b d \n" +
137 "$gdxin \n" +
138 " \n" +
139 "$if not set dbIn2 $abort 'no file name for in-database 2 file provided' \n" +
140 "$gdxin %dbIn2% \n" +
141 "$load f \n" +
142 "$gdxin \n" +
143 " \n" +
144 " Parameter c(i,j) transport cost in thousands of dollars per case ; \n" +
145 " \n" +
146 " c(i,j) = f * d(i,j) / 1000 ; \n" +
147 " \n" +
148 " Variables \n" +
149 " x(i,j) shipment quantities in cases \n" +
150 " z total transportation costs in thousands of dollars ; \n" +
151 " \n" +
152 " Positive Variable x ; \n" +
153 " \n" +
154 " Equations \n" +
155 " \n" +
156 " cost define objective function \n" +
157 " supply(i) observe supply limit at plant i \n" +
158 " demand(j) satisfy demand at market j ; \n" +
159 " \n" +
160 " cost .. z =e= sum((i,j), c(i,j)*x(i,j)) ; \n" +
161 " \n" +
162 " supply(i) .. sum(j, x(i,j)) =l= a(i) ; \n" +
163 " \n" +
164 " demand(j) .. sum(i, x(i,j)) =g= b(j) ; \n" +
165 " \n" +
166 " Model transport /all/ ; \n" +
167 " \n" +
168 " Solve transport using lp minimizing z ; \n" +
169 " \n" +
170 " Display x.l, x.m ; \n" +
171 "$if not set dbOut1 $abort 'no file name for out-database 1 file provided' \n" +
172 "execute_unload '%dbOut1%', x, z; \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::GAMSOptions::defines
void defines(String defStr, String asStr)
com::gams::api::GAMSOptions::getDefinitionOf
String getDefinitionOf(String str)
com::gams::api::GAMSOptions::setAllModelTypes
void setAllModelTypes(String value)
com::gams::api::GAMSOptions::setSolveLink
void setSolveLink(GAMSOptions.ESolveLink x)
com::gams::api::GAMSWorkspace::addDatabaseFromGDX
GAMSDatabase addDatabaseFromGDX(String gdxFileName)
com::gams::api::GAMSWorkspace::addJobFromString
GAMSJob addJobFromString(String source)
com::gams.examples.transport.TransportModel
This example shows the wrapper model of a transportation problem based on the simple GAMS [trnsport] ...
Definition: TransportModel.java:20
com::gams.examples.transport.TransportModel.getopt
GAMSOptions getopt()
Options for the execution of the trnsport model.
Definition: TransportModel.java:118
com::gams.examples.transport.TransportModel.getModelSource
String getModelSource()
Provide the source of trnsport model.
Definition: TransportModel.java:121
com::gams.examples.transport.TransportModel.run
void run(GAMSCheckpoint checkpoint, PrintStream output)
Executes the trnsport model.
Definition: TransportModel.java:79
com::gams.examples.transport.TransportModel.run
void run(GAMSCheckpoint checkpoint)
Executes the trnsport model.
Definition: TransportModel.java:62
com::gams.examples.transport.TransportModel.run
void run(PrintStream output)
Executes the trnsport model.
Definition: TransportModel.java:70
com::gams.examples.transport.TransportModel.getx
GAMSVariable getx()
x(i,j): shipment quantities in cases
Definition: TransportModel.java:112
com::gams.examples.transport.TransportModel.TransportModel
TransportModel(GAMSWorkspace ws)
TransportModel constructor.
Definition: TransportModel.java:34
com::gams.examples.transport.TransportModel.getf
GAMSParameter getf()
f: freight in dollars per case per thousand miles
Definition: TransportModel.java:109
com::gams.examples.transport.TransportModel.getb
GAMSParameter getb()
b(i): demand at market j in cases
Definition: TransportModel.java:103
com::gams.examples.transport.TransportModel.getz
GAMSVariable getz()
z: total transportation costs in thousands of dollars
Definition: TransportModel.java:115
com::gams.examples.transport.TransportModel.geta
GAMSParameter geta()
a(i): capacity of plant i in cases
Definition: TransportModel.java:100
com::gams.examples.transport.TransportModel.getd
GAMSParameter getd()
d(i,j): distance in thousands of miles
Definition: TransportModel.java:106
com::gams
Provides package namespace for Java interface and examples to General Algebraic Model System (GAMS).
com