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.
template<class T , class AccessOp >
labelList	subSizes (const List< T > &, AccessOp aop=accessOp< T >())
	Gets sizes of sublists.
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.

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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.
• combineOffset :
  similar and also adds offset.

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()

    List<myContainer> gatheredData(Pstream::nProcs());
    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

• ListListOps.H
• ListListOps.C

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Function Documentation

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

Combines sublists into one big list.

Definition at line 26 of file ListListOps.C.

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

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

Gets sizes of sublists.

Definition at line 53 of file ListListOps.C.

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

Like combine but also offsets sublists based on passed sizes.

Definition at line 67 of file ListListOps.C.