Functions
Foam::ListListOps Namespace Reference

Various utility functions to work on Lists of Lists (usually resulting from 'gather'ing and combining information from individual processors) More...

Functions

template<class AccessType , class T , class AccessOp >
AccessType combine (const List< T > &, AccessOp aop=accessOp< T >())
 Combines sublists into one big list. More...
 
template<class T , class AccessOp >
labelList subSizes (const List< T > &, AccessOp aop=accessOp< T >())
 Gets sizes of sublists. More...
 
template<class AccessType , class T , class AccessOp , class OffsetOp >
AccessType combineOffset (const List< T > &, const labelList &sizes, AccessOp aop, OffsetOp oop=offsetOp< T >())
 Like combine but also offsets sublists based on passed sizes. More...
 

Detailed Description

Various utility functions to work on Lists of Lists (usually resulting from 'gather'ing and combining information from individual processors)

- combine :
takes (elements of) sublists and appends them into one big list.

The access of data is through an AccessOp so that data can be 'gather'ed in one go, minimizing communication, and then picked apart and recombined.

Example:

// Assuming myContainer defined which holds all the data I want to
// transfer (say a pointField and a faceList). myContainer also defines
// access operators to
// access the individual elements, say myContainerPoints::operator(),
// and myContainerFaces::operator()
gatheredData[Pstream::myProcNo()] = myContainer(points, faces);
// Gather data onto master
Pstream::gatherList(gatheredData);
// Combine
pointField combinedPoints
(
ListListOps::combine<pointField>
(
gatheredData,
myContainerPoints()
)
);
// Combine and renumber (so combinedFaces indexes combinedPoints)
// Extract sizes of individual lists
labelList sizes
(
ListListOps::subSizes(gatheredData, myContainerPoints())
);
// Renumber using user-defined operator offsetOp<face>()
faceList combinedFaces
(
ListListOps::combineOffset<faceList>
(
gatheredData, sizes, myContainerFaces(), offsetOp<face>()
)
);
Source files

Function Documentation

◆ combine()

AccessType combine ( const List< T > &  lst,
AccessOp  aop = accessOp<T>() 
)

◆ subSizes()

labelList subSizes ( const List< T > &  lst,
AccessOp  aop = accessOp<T>() 
)

Gets sizes of sublists.

Definition at line 61 of file ListListOps.C.

References forAll, and List::size().

Referenced by PatchTools::gatherAndMerge().

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◆ combineOffset()

AccessType combineOffset ( const List< T > &  lst,
const labelList sizes,
AccessOp  aop,
OffsetOp  oop = offsetOp<T>() 
)

Like combine but also offsets sublists based on passed sizes.

Definition at line 75 of file ListListOps.C.

References forAll, Foam::sum(), and Foam::T().

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Foam::pointField
vectorField pointField
pointField is a vectorField.
Definition: pointFieldFwd.H:42
Foam::labelList
List< label > labelList
A List of labels.
Definition: labelList.H:56
Foam::UPstream::nProcs
static label nProcs(const label communicator=0)
Number of processes in parallel run.
Definition: UPstream.H:387
Foam::UPstream::myProcNo
static int myProcNo(const label communicator=0)
Number of this process (starting from masterNo() = 0)
Definition: UPstream.H:405
Foam::Pstream::gatherList
static void gatherList(const List< commsStruct > &comms, List< T > &Values, const int tag, const label comm)
Gather data but keep individual values separate.
Definition: gatherScatterList.C:49
Foam::faceList
List< face > faceList
Definition: faceListFwd.H:43
points
const pointField & points
Definition: gmvOutputHeader.H:1
Foam::ListListOps::subSizes
labelList subSizes(const List< T > &, AccessOp aop=accessOp< T >())
Gets sizes of sublists.
Definition: ListListOps.C:61
List
Definition: Test.C:19