Changeset 1542:0219ee65ffcc in lemon-0.x for test/lp_test.cc

Timestamp:

07/07/05 17:00:04 (19 years ago)

Author:

athos

Branch:

default

Phase:

public

Convert:

svn:c9d7d8f5-90d6-0310-b91f-818b3a526b0e/lemon/trunk@2037

Message:

Some testing of the LP interface: bugs got fixed.

File:

• test/lp_test.cc (modified) (3 diffs)

test/lp_test.cc

@@ -1 +1 @@
 #include<lemon/lp_skeleton.h>
 #include "test_tools.h"
+
 
 #ifdef HAVE_CONFIG_H
@@ -183 +184 @@
 }
 
+void solveAndCheck(LpSolverBase& lp, LpSolverBase::SolutionStatus stat, 
+                   double exp_opt){
+  lp.solve();
+  //int decimal,sign;
+  std::string buf1;
+  //  itoa(stat,buf1, 10);
+  check(lp.primalStatus()==stat,"Primalstatus should be "+buf1);
+    
+  if (stat ==  LpSolverBase::OPTIMAL){
+    check(std::abs(lp.primalValue()-exp_opt)<1e-3,
+          "Wrong optimal value: the right optimum is ");
+    //+ecvt(exp_opt,2)
+  }
+}
+ 
 void aTest(LpSolverBase & lp)
 {
   typedef LpSolverBase LP;
 
- //The following example is taken from the book by Gáspár and Temesi, page 39.
+ //The following example is very simple
 
   typedef LpSolverBase::Row Row;
@@ -198 +214 @@
 
   //Constraints
-  lp.addRow(3*x1+2*x2 >=6);  
-  lp.addRow(-1*x1+x2<=4);  
-  lp.addRow(5*x1+8*x2<=40);  
-  lp.addRow(x1-2*x2<=4);  
+  Row upright=lp.addRow(x1+x2 <=1);  
+  lp.addRow(x1+x2 >=-1);  
+  lp.addRow(x1-x2 <=1);  
+  lp.addRow(x1-x2 >=-1);  
   //Nonnegativity of the variables
   lp.colLowerBound(x1, 0);
   lp.colLowerBound(x2, 0);
   //Objective function
-  lp.setObj(2*x1+x2);
+  lp.setObj(x1+x2);
 
   lp.max();
-  lp.solve();
-
-  double opt=122.0/9.0;
-  
-  if (lp.primalStatus()==LpSolverBase::OPTIMAL){
-    std::cout<< "Z = "<<lp.primalValue()
-             << " (error = " << lp.primalValue()-opt
-             << "); x1 = "<<lp.primal(x1)
-             << "; x2 = "<<lp.primal(x2)
-             <<std::endl;
-    
-  }
-  else{
-    std::cout<<"Optimal solution not found!"<<std::endl;
-  }
-
-  check(lp.primalStatus()==LpSolverBase::OPTIMAL,"Primalstatus should be OPTIMAL");
-
-  check(std::abs(lp.primalValue()-opt)<1e-3,
-        "Wrong optimal value: the right optimum is 122/9 (13.555555...)");
-
+
+  //Maximization of x1+x2
+  //over the triangle with vertices (0,0) (0,1) (1,0)
+  double expected_opt=1;
+  solveAndCheck(lp, LpSolverBase::OPTIMAL, expected_opt);
+  
+  //Minimization
+  lp.min();
+  expected_opt=0;
+  solveAndCheck(lp, LpSolverBase::OPTIMAL, expected_opt);
+  
+  //Vertex (-1,0) instead of (0,0)
+  lp.colLowerBound(x1, -LpSolverBase::INF);
+  expected_opt=-1;
+  solveAndCheck(lp, LpSolverBase::OPTIMAL, expected_opt);
+
+  //Erase one constraint and return to maximization
+  lp.eraseRow(upright);
+  lp.max();
+  expected_opt=LpSolverBase::INF;
+  solveAndCheck(lp, LpSolverBase::INFINITE, expected_opt);
+
+  //Infeasibilty
+  lp.addRow(x1+x2 <=-2);  
+  solveAndCheck(lp, LpSolverBase::INFEASIBLE, expected_opt);
+
+  //Change problem and forget to solve
+  lp.min();
+  check(lp.primalStatus()==LpSolverBase::UNDEFINED,"Primalstatus should be UNDEFINED");
+
+//   lp.solve();
+//   if (lp.primalStatus()==LpSolverBase::OPTIMAL){
+//     std::cout<< "Z = "<<lp.primalValue()
+//           << " (error = " << lp.primalValue()-expected_opt
+//           << "); x1 = "<<lp.primal(x1)
+//           << "; x2 = "<<lp.primal(x2)
+//           <<std::endl;
+    
+//   }
+//   else{
+//     std::cout<<lp.primalStatus()<<std::endl;
+//     std::cout<<"Optimal solution not found!"<<std::endl;
+//   }
+
+ 
 
 }