Transport12.java
1package com.gams.examples.transport;
2 
3 import java.io.File;
4 import java.io.PrintStream;
5 import java.util.ArrayList;
6 import java.util.Collections;
7 import java.util.List;
8 
9 import com.gams.api.GAMSCheckpoint;
10 import com.gams.api.GAMSDatabase;
11 import com.gams.api.GAMSEquation;
12 import com.gams.api.GAMSEquationRecord;
13 import com.gams.api.GAMSException;
14 import com.gams.api.GAMSGlobals;
15 import com.gams.api.GAMSJob;
16 import com.gams.api.GAMSModelInstance;
17 import com.gams.api.GAMSModelInstanceOpt;
18 import com.gams.api.GAMSModifier;
19 import com.gams.api.GAMSOptions;
20 import com.gams.api.GAMSParameter;
21 import com.gams.api.GAMSParameterRecord;
22 import com.gams.api.GAMSSet;
23 import com.gams.api.GAMSSetRecord;
24 import com.gams.api.GAMSSymbol;
25 import com.gams.api.GAMSVariable;
26 import com.gams.api.GAMSVariableRecord;
27 import com.gams.api.GAMSWorkspace;
28 import com.gams.api.GAMSWorkspaceInfo;
29 
34 public class Transport12
35 {
36  public static void main(String[] args)
37  {
38  // check workspace info from command line arguments
39  GAMSWorkspaceInfo wsInfo = new GAMSWorkspaceInfo();
40  if (args.length > 0)
41  wsInfo.setSystemDirectory( args[0] );
42  // create a directory
43  File workingDirectory = new File(System.getProperty("user.dir"), "Transport12");
44  workingDirectory.mkdir();
45  wsInfo.setWorkingDirectory(workingDirectory.getAbsolutePath());
46  // create a workspace
47  GAMSWorkspace ws = new GAMSWorkspace(wsInfo);
48 
49  // initialize a checkpont by running a job
50  GAMSCheckpoint cp = ws.addCheckpoint();
51 
52  GAMSJob t12 = ws.addJobFromString(model);
53  t12.run(cp);
54 
55  // create a ModelInstance and solve it multiple times with different scalar bmult
56  GAMSModelInstance mi = cp.addModelInstance();
57 
58  double[] bmultlist = new double[] { 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3 };
59 
60  GAMSDatabase db1 = ws.addDatabase();
61 
62  GAMSSet scen1 = db1.addSet("scen", 1, "");
63  GAMSParameter bmult = db1.addParameter("bmultlist", "", scen1);
64  GAMSParameter zscen1 = db1.addParameter("zscen", "", scen1);
65 
66  int i = 0;
67  for (double b : bmultlist)
68  {
69  bmult.addRecord("s" + i).setValue(b);
70  scen1.addRecord("s" + i);
71  i++;
72  }
73 
74  GAMSSet dict = db1.addSet("dict",3,"");
75  dict.addRecord( new String[]{ scen1.getName(), "scenario", "" } );
76  dict.addRecord( new String[]{"bmult", "param", bmult.getName() } );
77  dict.addRecord( new String[]{"z", "level", zscen1.getName()} );
78 
79  GUSSCall(dict, mi, "transport use lp min z", null, null, null); //System.out);
80 
81  for (GAMSParameterRecord rec : db1.getParameter(zscen1.getName()))
82  System.out.println(rec.getKey(0) + " obj: " + rec.getValue());
83 
84  //*******************
85 
86  GAMSModelInstance mi2 = cp.addModelInstance();
87  GAMSDatabase db2 = ws.addDatabase();
88 
89  GAMSSet scen2 = db2.addSet("scen", 1, "");
90  GAMSParameter zscen2 = db2.addParameter("zscen", "", scen2);
91  GAMSParameter xup = db2.addParameter("xup", 3, "");
92 
93  for (int j = 0; j < 4; j++) {
94  for (GAMSSetRecord irec : t12.OutDB().getSet("i"))
95  for (GAMSSetRecord jrec : t12.OutDB().getSet("j"))
96  {
97  String[] keys = new String[] { "s" + j, irec.getKey(0), jrec.getKey(0) };
98  xup.addRecord(keys).setValue(j+1);
99  }
100  scen2.addRecord("s" + j);
101  }
102 
103  GAMSSet dict2 = db2.addSet("dict", 3, "");
104  dict2.addRecord( new String[] {scen2.getName(), "scenario", ""} );
105  dict2.addRecord( new String[] {"x", "lower", xup.getName()} );
106  dict2.addRecord( new String[] {"z", "level", zscen2.getName()} );
107 
108  GUSSCall(dict2, mi2, "transport use lp min z", null, null, System.out);
109 
110  for (GAMSParameterRecord rec : db2.getParameter(zscen2.getName()))
111  System.out.println(rec.getKey(0) + " obj: " + rec.getValue());
112  }
113 
114  // Needs to be called with an uninstantiated GAMSModelInstance
115  static void GUSSCall(GAMSSet dict, GAMSModelInstance mi, String solveStatement, GAMSOptions opt, GAMSModelInstanceOpt miOpt, PrintStream output)
116  {
117  List<Object[]> modifierList = Collections.synchronizedList( new ArrayList<Object[]>() );
118 
119  if (dict.getDimension() != 3)
120  throw new GAMSException("Dict needs to be 3-dimensional");
121 
122  String scenName = dict.getFirstRecord(new String[] { " ", "scenario", " " }).getKey(0);
123  GAMSSet scenSymbol = dict.getDatabase().getSet(scenName);
124 
125  for (GAMSSetRecord rec : dict)
126  {
127 
128  if (rec.getKey(1).toLowerCase().equals("scenario"))
129  continue;
130  if (rec.getKey(1).toLowerCase().equals("param"))
131  {
132  int modifierDim = dict.getDatabase().getParameter(rec.getKey(2)).getDimension() - scenSymbol.getDimension();
133  if (modifierDim < 0)
134  throw new GAMSException("Dimension of " + rec.getKey(2) + " too small");
135  GAMSModifier mod = new GAMSModifier(mi.SyncDB().addParameter(rec.getKey(0), modifierDim, ""));
136  GAMSParameter param = dict.getDatabase().getParameter( rec.getKey(2));
137  modifierList.add(
138  new Object[] { mod, param }
139  );
140  }
141  else if ((rec.getKey(1).toLowerCase().equals("lower")) ||
142  (rec.getKey(1).toLowerCase().equals("upper")) ||
143  (rec.getKey(1).toLowerCase().equals("fixed")))
144  {
145  int modifierDim = (int) (dict.getDatabase().getParameter(rec.getKey(2)).getDimension() - scenSymbol.getDimension());
146  if (modifierDim < 0)
147  throw new GAMSException("Dimension of " + rec.getKey(2) + " too small");
148  GAMSVariable modifierVar = null;
149  try {
150  modifierVar = dict.getDatabase().getVariable(rec.getKey(0));
151  }
152  catch (Exception e) {
153  modifierVar = mi.SyncDB().addVariable(rec.getKey(0),modifierDim, GAMSGlobals.VarType.FREE, "");
154  }
155  if (rec.getKey(1).toLowerCase().equals("lower"))
156  {
157  GAMSModifier mod = new GAMSModifier(modifierVar, GAMSGlobals.UpdateAction.LOWER, mi.SyncDB().addParameter(rec.getKey(2), modifierDim, ""));
158  GAMSParameter param = dict.getDatabase().getParameter(rec.getKey(2));
159  modifierList.add(
160  new Object[] { mod , param }
161  );
162  }
163  else if (rec.getKey(1).toLowerCase().equals("upper"))
164  {
165  GAMSModifier mod = new GAMSModifier(modifierVar, GAMSGlobals.UpdateAction.UPPER, mi.SyncDB().addParameter(rec.getKey(2), modifierDim, ""));
166  GAMSParameter param = dict.getDatabase().getParameter(rec.getKey(2));
167  modifierList.add(
168  new Object[] { mod , param }
169  );
170  }
171  else { // fixed
172  GAMSModifier mod = new GAMSModifier(modifierVar, GAMSGlobals.UpdateAction.FIXED, mi.SyncDB().addParameter(rec.getKey(2), modifierDim, ""));
173  GAMSParameter param = dict.getDatabase().getParameter(rec.getKey(2));
174  modifierList.add(
175  new Object[] { mod , param }
176  );
177  }
178  }
179  else if ((rec.getKey(1).toLowerCase().equals("level")) || (rec.getKey(1).toLowerCase().equals( "marginal")))
180  {
181  // Check that parameter exists in GAMSDatabase, will throw an exception if not
182  @SuppressWarnings("unused")
183  GAMSParameter x = dict.getDatabase().getParameter(rec.getKey(2));
184  }
185  else
186  throw new GAMSException("Cannot handle UpdateAction " + rec.getKey(1));
187  }
188 
189  List<GAMSModifier> mL = Collections.synchronizedList( new ArrayList<GAMSModifier>() );
190  for (Object[] tuple : modifierList) {
191  if (tuple[0] instanceof GAMSModifier)
192  mL.add( (GAMSModifier) tuple[0] );
193  }
194  GAMSModifier[] mods = (GAMSModifier[]) mL.toArray(new GAMSModifier[mL.size()]);
195 
196  mi.instantiate(solveStatement, opt, mods);
197 
198  List<Object[]> outList = Collections.synchronizedList( new ArrayList<Object[]>() );
199 
200  for (GAMSSetRecord s : scenSymbol)
201  {
202  for (Object[] tuple : modifierList)
203  {
204  GAMSParameter p;
205  GAMSParameter pscen = (GAMSParameter) tuple[1];
206 
207  GAMSModifier m = (GAMSModifier) tuple[0];
208  if (m.getDataSymbol() == null)
209  p = (GAMSParameter)m.getGamsSymbol();
210  else
211  p = m.getDataSymbol();
212 
213  // Implemented SymbolUpdateType=BaseCase
214  p.clear();
215 
216  GAMSParameterRecord rec;
217  String[] filter = new String[pscen.getDimension()];
218  for (int i = 0; i < scenSymbol.getDimension(); i++)
219  filter[i] = s.getKey(i);
220  for (int i = scenSymbol.getDimension(); i < pscen.getDimension(); i++)
221  filter[i] = " ";
222 
223  try
224  {
225  rec = pscen.getFirstRecord(filter);
226  } catch (GAMSException e) {
227  continue;
228  }
229  do
230  { String[] myKeys = new String[p.getDimension()];
231  for (int i = 0; i < p.getDimension(); i++)
232  myKeys[i] = rec.getKey(scenSymbol.getDimension()+i);
233  p.addRecord(myKeys).setValue( rec.getValue() );
234  } while (rec.moveNext());
235  }
236 
237  mi.solve(GAMSModelInstance.SymbolUpdateType.BASECASE, output, miOpt);
238  if (outList.size() == 0)
239  {
240  for (GAMSSetRecord rec : dict)
241  {
242  if ((rec.getKey(1).toLowerCase().equals("level")) || (rec.getKey(1).toLowerCase().equals("marginal")))
243  {
244  GAMSSymbol<?> sym = mi.SyncDB().getSymbol(rec.getKey(0));
245  GAMSParameter param = dict.getDatabase().getParameter(rec.getKey(2));
246  String str = rec.getKey(1).toLowerCase();
247  outList.add(
248  new Object[] { sym, param, str }
249  );
250  }
251  }
252  }
253  for (Object[] tuple : outList)
254  {
255  GAMSSymbol<?> symbol = (GAMSSymbol<?>) tuple[0];
256  GAMSParameter param = (GAMSParameter) tuple[1];
257  String str = (String)tuple[2];
258  String[] myKeys = new String[scenSymbol.getDimension() + symbol.getFirstRecord().getKeys().length];
259  for (int i = 0; i < scenSymbol.getDimension(); i++)
260  myKeys[i] = s.getKey(i);
261 
262  if ((str.equals("level")) && (symbol instanceof GAMSVariable))
263  {
264  GAMSVariable var = (GAMSVariable) symbol;
265  for (GAMSVariableRecord rec : var)
266  {
267  for (int i = 0; i < rec.getKeys().length; i++)
268  myKeys[scenSymbol.getDimension() + i] = s.getKey(i);
269  param.addRecord(myKeys).setValue( rec.getLevel() );
270  }
271  }
272  else if ((str.equals("level")) && (symbol instanceof GAMSEquation))
273  {
274  GAMSEquation eq = (GAMSEquation) symbol;
275  for (GAMSEquationRecord rec : eq)
276  {
277  for (int i = 0; i < rec.getKeys().length; i++)
278  myKeys[scenSymbol.getDimension() + i] = s.getKey(i);
279  param.addRecord(myKeys).setValue( rec.getLevel() );
280  }
281  }
282  else if ((str.equals("marginal")) && (symbol instanceof GAMSVariable))
283  {
284  GAMSVariable var = (GAMSVariable) symbol;
285  for (GAMSVariableRecord rec : var)
286  {
287  for (int i = 0; i < rec.getKeys().length; i++)
288  myKeys[scenSymbol.getDimension() + i] = s.getKey(i);
289  param.addRecord(myKeys).setValue( rec.getMarginal() );
290  }
291  }
292  else if ((str.equals("marginal")) && (symbol instanceof GAMSEquation))
293  {
294  GAMSEquation eq = (GAMSEquation) symbol;
295  for (GAMSEquationRecord rec : eq)
296  {
297  for (int i = 0; i < rec.getKeys().length; i++)
298  myKeys[scenSymbol.getDimension() + i] = s.getKey(i);
299  param.addRecord(myKeys).setValue( rec.getMarginal() );
300  }
301  }
302  }
303  }
304  }
305 
306  static String model =
307  "Sets \n" +
308  " i canning plants / seattle, san-diego / \n" +
309  " j markets / new-york, chicago, topeka / ; \n" +
310  " \n" +
311  "Parameters \n" +
312  " \n" +
313  " a(i) capacity of plant i in cases \n" +
314  " / seattle 350 \n" +
315  " san-diego 600 / \n" +
316  " \n" +
317  " b(j) demand at market j in cases \n" +
318  " / new-york 325 \n" +
319  " chicago 300 \n" +
320  " topeka 275 / ; \n" +
321  " \n" +
322  "Table d(i,j) distance in thousands of miles \n" +
323  " new-york chicago topeka \n" +
324  " seattle 2.5 1.7 1.8 \n" +
325  " san-diego 2.5 1.8 1.4 ; \n" +
326  " \n" +
327  "Scalar f freight in dollars per case per thousand miles /90/ ;\n" +
328  "Scalar bmult demand multiplier /1/; \n" +
329  " \n" +
330  "Parameter c(i,j) transport cost in thousands of dollars per case ; \n" +
331  " \n" +
332  " c(i,j) = f * d(i,j) / 1000 ; \n" +
333  " \n" +
334  "Variables \n" +
335  " x(i,j) shipment quantities in cases \n" +
336  " z total transportation costs in thousands of dollars ; \n" +
337  " \n" +
338  "Positive Variable x ; \n" +
339  " \n" +
340  "Equations \n" +
341  " cost define objective function \n" +
342  " supply(i) observe supply limit at plant i \n" +
343  " demand(j) satisfy demand at market j ; \n" +
344  " \n" +
345  "cost .. z =e= sum((i,j), c(i,j)*x(i,j)) ; \n" +
346  " \n" +
347  "supply(i) .. sum(j, x(i,j)) =l= a(i) ; \n" +
348  " \n" +
349  "demand(j) .. sum(i, x(i,j)) =g= bmult*b(j) ; \n" +
350  " \n" +
351  "Model transport /all/ ; \n" +
352  " \n";
353 
354 }
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com::gams.examples.transport.Transport12
This example demonstrates how to implement a GUSS approach using the GAMS Java API and the GAMS [trns...
Definition: Transport12.java:35
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