--- trunk/mdtools/mpi_implementation/mpiSimulation.cpp	2002/12/04 21:19:38	194
+++ trunk/mdtools/mpi_implementation/mpiSimulation.cpp	2002/12/05 18:53:40	195
@@ -1,4 +1,4 @@
-#include <cstdlib>
+i#include <cstdlib>
 #include <cstring>
 #include <mpi.h>
 
@@ -9,20 +9,136 @@ mpiSimulation::mpiSimulation(SimInfo* the_entryPlug)
 
 mpiSimulation::mpiSimulation(SimInfo* the_entryPlug)
 {
-  entryPlug = the_entryPlug
-
+  entryPlug = the_entryPlug;
+  
   numberProcessors = MPI::COMM_WORLD.Get_size();
   myNode = worldRank;
-
-  // let the simulkation know were there.
+  
+  // let the simulation know were there.
   entryPlug->mpiSim = this;
 }
 
 
 mpiSimulation::~mpiSimulation(){
-
+  
   // empty for now
-
+  
 }
 
 
+void mpiSimulation::divideLabor(int nComponents, MoleculeStamp** compStamps, int* componentsNmol ){
+  
+  double numerator;
+  double denominator;
+  double precast;
+
+  int nTarget;
+  int molIndex, atomIndex, compIndex, compStart;
+  int done;
+  int nLocal;
+  int i;
+  int smallDiff, bigDiff;
+
+  int testSum;
+
+  numerator = (double) entryPlug->n_atoms;
+  denominator = (double) numberProcessors;
+  precast = numerator / denominator;
+  nTarget = (int)( precast + 0.5 );
+  
+  molIndex = 0;
+  atomIndex = 0;
+  compIndex = 0;
+  compStart = 0;
+  for( i=0; i<(numberProcessors-1); i++){
+    
+    done = 0;
+    nLocal = 0;
+
+    if( i == myNode ){
+      myMolStart = molIndex;
+      myAtomStart = atomIndex;
+    }
+    
+    while( !done ){
+      
+      if( (molIndex-compStart) >= componentsNmol[compIndex] ){
+	compStart = molIndex;
+	compIndex++;
+	continue;
+      }
+
+      nLocal += compStamps[compIndex]->getNAtoms();
+      atomIndex += compStamps[compIndex]->getNAtoms();
+      molIndex++;
+      
+      if ( nLocal == nTarget ) done = 1;
+      
+      else if( nLocal < nTarget ){
+	smallDiff = nTarget - nLocal;
+      }
+      else if( nLocal > nTarget ){
+	bigDiff = nLocal - nTarget;
+	
+	if( bigDiff < smallDiff ) done = 1;
+	else{
+	  molIndex--;
+	  atomIndex -= compStamps[compIndex]->getNAtoms();
+	  nLocal -= compStamps[compIndex]->getNAtoms();
+	  done = 1;
+	}
+      }
+    }
+    
+    if( i == myNode ){
+      myMolEnd = (molIndex - 1);
+      myAtomEnd = (atomIndex - 1);
+      myNlocal = nLocal;
+    }
+    
+    numerator = (double)( entryPlug->n_atoms - atomIndex );
+    denominator = (double)( numberProcessors - (i+1) );
+    precast = numerator / denominator;
+    nTarget = (int)( precast + 0.5 );
+  }
+  
+  if( myNode == numberProcessors-1 ){
+      myMolStart = molIndex;
+      myAtomStart = atomIndex;
+
+      nLocal = 0;
+      while( compIndex < nComponents ){
+	
+	if( (molIndex-compStart) >= componentsNmol[compIndex] ){
+	  compStart = molIndex;
+	  compIndex++;
+	  continue;
+	}
+
+	nLocal += compStamps[compIndex]->getNAtoms();
+	atomIndex += compStamps[compIndex]->getNAtoms();
+	molIndex++;
+      }
+      
+      myMolEnd = (molIndex - 1);
+      myAtomEnd = (atomIndex - 1);
+      myNlocal = nLocal;   
+  }
+
+
+  MPI_Allreduce( &Nlocal, &testSum, 1, MPI_INT, MPI_SUM, MPI_COMM_WORLD );
+  
+  if( myNode == 0 ){
+    if( testSum != entryPlug->n_atoms ){
+      sprintf( painCave.errMsg,
+	       "The summ of all nLocals, %d, did not equal the total number of atoms, %d.\n",
+	       testSum, entryPlug->n_atoms );
+      painCave.isFatal = 1;
+      simError();
+    }
+  }
+
+  sprintf( checkPointMsg,
+	   "Successfully divided the molecules among the processors.\n" );
+  MPIcheckPoint();
+}