std::shared_ptr<MapEpetra> MapEpetra::createRootMap (Int const root) const
{
std::shared_ptr<MapEpetra> rootMap ( new MapEpetra ( Epetra_Util::Create_Root_Map ( *getUniqueMap(), root ) ) );
return rootMap;
}
// FIXME long long
Epetra_Map
Epetra_Util::Create_Root_Map(const Epetra_Map& usermap,
int root)
{
int numProc = usermap.Comm().NumProc();
if (numProc==1) {
Epetra_Map newmap(usermap);
return(newmap);
}
const Epetra_Comm & comm = usermap.Comm();
bool isRoot = usermap.Comm().MyPID()==root;
//if usermap is already completely owned by root then we'll just return a copy of it.
int quickreturn = 0;
int globalquickreturn = 0;
if (isRoot) {
if (usermap.NumMyElements()==usermap.NumGlobalElements64()) quickreturn = 1;
}
else {
if (usermap.NumMyElements()==0) quickreturn = 1;
}
usermap.Comm().MinAll(&quickreturn, &globalquickreturn, 1);
if (globalquickreturn==1) {
Epetra_Map newmap(usermap);
return(newmap);
}
// Linear map: Simple case, just put all GIDs linearly on root processor
if (usermap.LinearMap() && root!=-1) {
int numMyElements = 0;
if (isRoot) numMyElements = usermap.MaxAllGID64()+1; // FIXME long long
Epetra_Map newmap(-1, numMyElements, usermap.IndexBase(), comm);
return(newmap);
}
if (!usermap.UniqueGIDs())
throw usermap.ReportError("usermap must have unique GIDs",-1);
// General map
// Build IntVector of the GIDs, then ship them to root processor
int numMyElements = usermap.NumMyElements();
Epetra_Map allGidsMap(-1, numMyElements, 0, comm);
Epetra_IntVector allGids(allGidsMap);
for (int i=0; i<numMyElements; i++) allGids[i] = usermap.GID64(i);
int numGlobalElements = usermap.NumGlobalElements64();
if (root!=-1) {
int n1 = 0; if (isRoot) n1 = numGlobalElements;
Epetra_Map allGidsOnRootMap(-1, n1, 0, comm);
Epetra_Import importer(allGidsOnRootMap, allGidsMap);
Epetra_IntVector allGidsOnRoot(allGidsOnRootMap);
allGidsOnRoot.Import(allGids, importer, Insert);
Epetra_Map rootMap(-1, allGidsOnRoot.MyLength(), allGidsOnRoot.Values(), usermap.IndexBase(), comm);
return(rootMap);
}
else {
int n1 = numGlobalElements;
Epetra_LocalMap allGidsOnRootMap(n1, 0, comm);
Epetra_Import importer(allGidsOnRootMap, allGidsMap);
Epetra_IntVector allGidsOnRoot(allGidsOnRootMap);
allGidsOnRoot.Import(allGids, importer, Insert);
Epetra_Map rootMap(-1, allGidsOnRoot.MyLength(), allGidsOnRoot.Values(), usermap.IndexBase(), comm);
return(rootMap);
}
}
