Changeset 1883 for stable/2.8/Cbc/src/CbcHeuristicFPump.cpp

Timestamp:

Apr 6, 2013 9:33:15 AM (7 years ago)

Author:

stefan

Message:

sync with trunk rev 1882

Location:

stable/2.8/Cbc

Files:

• . (modified) (1 prop)
• src/CbcHeuristicFPump.cpp (modified) (2 diffs)

stable/2.8/Cbc/src/CbcHeuristicFPump.cpp

@@ -496 +496 @@
             maximumPasses = 100; // feasibility problem?
         }
+        randomNumberGenerator_.randomize();
         if (model_->getRandomSeed()!=-1)
           clpSolver->getModelPtr()->setRandomSeed(randomNumberGenerator_.getSeed());
+        clpSolver->getModelPtr()->randomNumberGenerator()->randomize();
       }
     }
@@ -1023 +1025 @@
                     offset += costValue * newSolution[iColumn];
                 }
+                if (numberPasses==1 && !totalNumberPasses && (model_->specialOptions()&8388608)!=0) {
+                  // doing multiple solvers - make a real difference - flip 5%
+                  for (i = 0; i < numberIntegers; i++) {
+                    int iColumn = integerVariable[i];
+                    double value = floor(newSolution[iColumn]+0.5);
+                    if (fabs(value-solution[iColumn])>primalTolerance) {
+                      value = randomNumberGenerator_.randomDouble();
+                      if(value<0.05) {
+                        //printf("Flipping %d - random %g\n",iColumn,value);
+                        solver->setObjCoeff(iColumn,-solver->getObjCoefficients()[iColumn]);
+                      }
+                    }
+                  }
+                }
                 solver->setDblParam(OsiObjOffset, -offset);
                 if (!general && false) {