C++ (Cpp) SCIPallowDualReds Examples

Example #1

File: prop_dualfix.c Project: gorhan/LFOS

/** presolving method of propagator */
static
SCIP_DECL_PROPPRESOL(propPresolDualfix)
{  /*lint --e{715}*/
   SCIP_Bool cutoff;
   SCIP_Bool unbounded;
   int oldnfixedvars;

   assert(prop != NULL);
   assert(strcmp(SCIPpropGetName(prop), PROP_NAME) == 0);
   assert(result != NULL);

   *result = SCIP_DIDNOTRUN;

   if( !SCIPallowDualReds(scip) )
      return SCIP_OKAY;

   cutoff = FALSE;
   unbounded = FALSE;
   oldnfixedvars = *nfixedvars;

   SCIP_CALL( performDualfix(scip, nfixedvars, &unbounded, &cutoff) );

   /* evaluate propagation result */
   if( cutoff )
      *result = SCIP_CUTOFF;
   else if( unbounded )
      *result = SCIP_UNBOUNDED;
   else if( *nfixedvars > oldnfixedvars )
      *result = SCIP_SUCCESS;
   else
      *result = SCIP_DIDNOTFIND;

   return SCIP_OKAY;
}

Example #2

File: prop_dualfix.c Project: gorhan/LFOS

/** execution method of propagator */
static
SCIP_DECL_PROPEXEC(propExecDualfix)
{  /*lint --e{715}*/
   int nfixedvars;
   SCIP_Bool cutoff;
   SCIP_Bool unbounded;

   assert(prop != NULL);
   assert(strcmp(SCIPpropGetName(prop), PROP_NAME) == 0);
   assert(result != NULL);

   *result = SCIP_DIDNOTRUN;

   /** @warning Don't run in probing or in repropagation since this can lead to wrong conclusion
    *
    *  do not run if propagation w.r.t. current objective is not allowed
    */
   if( SCIPinProbing(scip) || SCIPinRepropagation(scip) || !SCIPallowDualReds(scip) )
      return SCIP_OKAY;

   cutoff = FALSE;
   unbounded = FALSE;
   nfixedvars = 0;

   SCIP_CALL( performDualfix(scip, &nfixedvars, &unbounded, &cutoff) );

   /* evaluate propagation result */
   if( cutoff )
      *result = SCIP_CUTOFF;
   else if( unbounded )
      *result = SCIP_UNBOUNDED;
   else if( nfixedvars > 0 )
      *result = SCIP_REDUCEDDOM;
   else
      *result = SCIP_DIDNOTFIND;

   return SCIP_OKAY;
}

Example #3

File: presol_dualagg.c Project: bubuker/keggle_santa

/** execution method of presolver */
static
SCIP_DECL_PRESOLEXEC(presolExecDualagg)
{  /*lint --e{715}*/
   SCIPMILPMATRIX* matrix;
   SCIP_Bool initialized;
   SCIP_Bool complete;

   assert(result != NULL);
   *result = SCIP_DIDNOTRUN;

   if( (SCIPgetStage(scip) != SCIP_STAGE_PRESOLVING) || SCIPinProbing(scip) || SCIPisNLPEnabled(scip) )
      return SCIP_OKAY;

   if( SCIPisStopped(scip) || SCIPgetNActivePricers(scip) > 0 )
      return SCIP_OKAY;

   if( SCIPgetNBinVars(scip) == 0 )
      return SCIP_OKAY;

   if( !SCIPallowDualReds(scip) )
      return SCIP_OKAY;

   *result = SCIP_DIDNOTFIND;

   matrix = NULL;
   SCIP_CALL( SCIPmatrixCreate(scip, &matrix, &initialized, &complete) );

   /* we only work on pure MIPs currently */
   if( initialized && complete )
   {
      AGGRTYPE* aggtypes;
      SCIP_VAR** binvars;
      int nvaragg;
      int ncols;

      ncols = SCIPmatrixGetNColumns(matrix);
      nvaragg = 0;

      SCIP_CALL( SCIPallocBufferArray(scip, &aggtypes, ncols) );
      BMSclearMemoryArray(aggtypes, ncols);

      SCIP_CALL( SCIPallocBufferArray(scip, &binvars, ncols) );
      SCIPdebug( BMSclearMemoryArray(binvars, ncols) );

      /* search for aggregations */
      SCIP_CALL( findUplockAggregations(scip, matrix, &nvaragg, aggtypes, binvars) );
      SCIP_CALL( findDownlockAggregations(scip, matrix, &nvaragg, aggtypes, binvars) );

      /* apply aggregations, if we found any */
      if( nvaragg > 0 )
      {
         int v;

         for( v = 0; v < ncols; v++ )
         {
            if( aggtypes[v] != NOAGG )
            {
               SCIP_Bool infeasible;
               SCIP_Bool redundant;
               SCIP_Bool aggregated;
               SCIP_Real ub;
               SCIP_Real lb;

               ub = SCIPmatrixGetColUb(matrix, v);
               lb = SCIPmatrixGetColLb(matrix, v);

               /* aggregate variable */
               assert(binvars[v] != NULL);
               if( aggtypes[v] == BIN0UBOUND )
               {
                  SCIP_CALL( SCIPaggregateVars(scip, SCIPmatrixGetVar(matrix, v), binvars[v], 1.0, ub-lb,
                        ub, &infeasible, &redundant, &aggregated) );
               }
               else
               {
                  assert(aggtypes[v] == BIN0LBOUND);
                  SCIP_CALL( SCIPaggregateVars(scip, SCIPmatrixGetVar(matrix, v), binvars[v], 1.0, lb-ub,
                        lb, &infeasible, &redundant, &aggregated) );
               }

               /* infeasible aggregation */
               if( infeasible )
               {
                  SCIPdebugMessage(" -> infeasible aggregation\n");
                  *result = SCIP_CUTOFF;
                  return SCIP_OKAY;
               }

               if( aggregated )
                  (*naggrvars)++;
            }
         }

         /* set result pointer */
         if( (*naggrvars) > 0 )
            *result = SCIP_SUCCESS;
      }

      SCIPfreeBufferArray(scip, &binvars);
      SCIPfreeBufferArray(scip, &aggtypes);
   }

   SCIPmatrixFree(scip, &matrix);

   return SCIP_OKAY;
}