Scotch domain decomposition. More...

Inheritance diagram for scotchDecomp:

Collaboration diagram for scotchDecomp:

Public Member Functions
	TypeName ("scotch")

	scotchDecomp (const dictionary &decompDict, const word &regionName="")

virtual	~scotchDecomp ()=default

virtual bool	parallelAware () const

virtual labelList	decompose (const polyMesh &mesh, const pointField &points, const scalarField &pointWeights) const

virtual labelList	decompose (const polyMesh &mesh, const labelList &agglom, const pointField &regionPoints, const scalarField &regionWeights) const

virtual labelList	decompose (const labelListList &globalCellCells, const pointField &cc, const scalarField &cWeights) const

virtual labelList	decompose (const pointField &points, const scalarField &pointWeights) const

virtual labelList	decompose (const pointField &points) const

virtual labelList	decompose (const polyMesh &mesh, const pointField &points, const scalarField &pointWeights) const=0

virtual labelList	decompose (const polyMesh &mesh, const pointField &points) const

virtual labelList	decompose (const polyMesh &mesh, const labelList &cellToRegion, const pointField &regionPoints, const scalarField &regionWeights) const

virtual labelList	decompose (const polyMesh &mesh, const labelList &cellToRegion, const pointField &regionPoints) const

virtual labelList	decompose (const labelListList &globalCellCells, const pointField &cc, const scalarField &cWeights) const=0

virtual labelList	decompose (const labelListList &globalCellCells, const pointField &cc) const

virtual labelList	decompose (const polyMesh &mesh, const scalarField &cellWeights, const boolList &blockedFace, const PtrList< labelList > &specifiedProcessorFaces, const labelList &specifiedProcessor, const List< labelPair > &explicitConnections) const

labelList	decompose (const polyMesh &mesh, const scalarField &cWeights) const

Public Member Functions inherited from metisLikeDecomp
virtual	~metisLikeDecomp ()=default

virtual labelList	decompose (const pointField &points, const scalarField &pointWeights) const

virtual labelList	decompose (const pointField &points) const

virtual labelList	decompose (const polyMesh &mesh, const pointField &points, const scalarField &pointWeights) const=0

virtual labelList	decompose (const polyMesh &mesh, const pointField &points) const

virtual labelList	decompose (const polyMesh &mesh, const labelList &cellToRegion, const pointField &regionPoints, const scalarField &regionWeights) const

virtual labelList	decompose (const polyMesh &mesh, const labelList &cellToRegion, const pointField &regionPoints) const

virtual labelList	decompose (const labelListList &globalCellCells, const pointField &cc, const scalarField &cWeights) const=0

virtual labelList	decompose (const labelListList &globalCellCells, const pointField &cc) const

virtual labelList	decompose (const polyMesh &mesh, const scalarField &cellWeights, const boolList &blockedFace, const PtrList< labelList > &specifiedProcessorFaces, const labelList &specifiedProcessor, const List< labelPair > &explicitConnections) const

labelList	decompose (const polyMesh &mesh, const scalarField &cWeights) const

Public Member Functions inherited from decompositionMethod
	TypeName ("decompositionMethod")

	declareRunTimeSelectionTable (autoPtr, decompositionMethod, dictionary,(const dictionary &decompDict, const word &regionName),(decompDict, regionName))

	decompositionMethod (const dictionary &decompDict, const word &regionName="")

virtual	~decompositionMethod ()=default

label	nDomains () const noexcept

virtual labelList	decompose (const pointField &points, const scalarField &pointWeights) const

virtual labelList	decompose (const pointField &points) const

virtual labelList	decompose (const polyMesh &mesh, const pointField &points) const

virtual labelList	decompose (const polyMesh &mesh, const labelList &cellToRegion, const pointField &regionPoints) const

virtual labelList	decompose (const labelListList &globalCellCells, const pointField &cc) const

void	setConstraints (const polyMesh &mesh, boolList &blockedFace, PtrList< labelList > &specifiedProcessorFaces, labelList &specifiedProcessor, List< labelPair > &explicitConnections) const

void	applyConstraints (const polyMesh &mesh, const boolList &blockedFace, const PtrList< labelList > &specifiedProcessorFaces, const labelList &specifiedProcessor, const List< labelPair > &explicitConnections, labelList &finalDecomp) const

virtual labelList	decompose (const polyMesh &mesh, const scalarField &cellWeights, const boolList &blockedFace, const PtrList< labelList > &specifiedProcessorFaces, const labelList &specifiedProcessor, const List< labelPair > &explicitConnections) const

labelList	decompose (const polyMesh &mesh, const scalarField &cWeights) const

Protected Member Functions
virtual label	decomposeSerial (const labelList &adjncy, const labelList &xadj, const List< scalar > &cWeights, labelList &decomp) const

	scotchDecomp (const scotchDecomp &)=delete

void	operator= (const scotchDecomp &)=delete

Protected Member Functions inherited from metisLikeDecomp
virtual label	decomposeGeneral (const labelList &adjncy, const labelList &xadj, const List< scalar > &cellWeights, labelList &decomp) const

	metisLikeDecomp (const metisLikeDecomp &)=delete

void	operator= (const metisLikeDecomp &)=delete

	metisLikeDecomp (const word &derivedType, const dictionary &decompDict, int select=selectionType::NULL_DICT)

	metisLikeDecomp (const word &derivedType, const dictionary &decompDict, const word &regionName, int select=selectionType::NULL_DICT)

Protected Member Functions inherited from decompositionMethod
const dictionary &	findCoeffsDict (const word &coeffsName, int select=selectionType::DEFAULT) const

Additional Inherited Members
Static Public Member Functions inherited from decompositionMethod
static label	nDomains (const dictionary &decompDict, const word &regionName="")

static const dictionary &	optionalRegionDict (const dictionary &decompDict, const word &regionName)

static autoPtr< decompositionMethod >	New (const dictionary &decompDict, const word &regionName="")

static void	calcCellCells (const polyMesh &mesh, const labelList &agglom, const label nLocalCoarse, const bool global, CompactListList< label > &cellCells)

static void	calcCellCells (const polyMesh &mesh, const labelList &agglom, const label nLocalCoarse, const bool parallel, CompactListList< label > &cellCells, CompactListList< scalar > &cellCellWeights)

Protected Types inherited from decompositionMethod
enum	selectionType { DEFAULT = 0, EXACT = 1, MANDATORY = 2, NULL_DICT = 4 }

Static Protected Member Functions inherited from decompositionMethod
static const dictionary &	findCoeffsDict (const dictionary &dict, const word &coeffsName, int select=selectionType::DEFAULT)

Protected Attributes inherited from metisLikeDecomp
const dictionary &	coeffsDict_

Protected Attributes inherited from decompositionMethod
const dictionary &	decompDict_

const dictionary &	decompRegionDict_

label	nDomains_

PtrList< decompositionConstraint >	constraints_

Detailed Description

Scotch domain decomposition.

When run in parallel will collect the whole graph on to the master, decompose and send back. Use ptscotchDecomp for proper distributed decomposition.

Coefficients dictionary: scotchCoeffs, coeffs.

Quoting from the Scotch forum, on the 2008-08-22 10:09, Francois PELLEGRINI posted the following details:

RE: Graph mapping 'strategy' string

Strategy handling in Scotch is a bit tricky. In order
not to be confused, you must have a clear view of how they are built.
Here are some rules:

1- Strategies are made up of "methods" which are combined by means of
"operators".

2- A method is of the form "m{param=value,param=value,...}", where "m"
is a single character (this is your first error: "f" is a method name,
not a parameter name).

3- There exist different sort of strategies : bipartitioning strategies,
mapping strategies, ordering strategies, which cannot be mixed. For
instance, you cannot build a bipartitioning strategy and feed it to a
mapping method (this is your second error).

To use the "mapCompute" routine, you must create a mapping strategy, not
a bipartitioning one, and so use stratGraphMap() and not
stratGraphBipart(). Your mapping strategy should however be based on the
"recursive bipartitioning" method ("b"). For instance, a simple (and
hence not very efficient) mapping strategy can be :

"b{sep=f}"

which computes mappings with the recursive bipartitioning method "b",
this latter using the Fiduccia-Mattheyses method "f" to compute its
separators.

If you want an exact partition (see your previous post), try
"b{sep=fx}".

However, these strategies are not the most efficient, as they do not
make use of the multi-level framework.

To use the multi-level framework, try for instance:

"b{sep=m{vert=100,low=h,asc=f}x}"

The current default mapping strategy in Scotch can be seen by using the
"-vs" option of program gmap. It is, to date:

r
{
    job=t,
    map=t,
    poli=S,
    sep=
    (
        m
        {
            asc=b
            {
                bnd=
                (
                    d{pass=40,dif=1,rem=1}
                 |
                )
                f{move=80,pass=-1,bal=0.002491},
                org=f{move=80,pass=-1,bal=0.002491},
                width=3
            },
            low=h{pass=10}
            f{move=80,pass=-1,bal=0.002491},
            type=h,
            vert=80,
            rat=0.8
        }
      | m
        {
            asc=b
            {
                bnd=
                (
                    d{pass=40,dif=1,rem=1}
                  |
                )
                f{move=80,pass=-1,bal=0.002491},
                org=f{move=80,pass=-1,bal=0.002491},
                width=3
            },
            low=h{pass=10}
            f{move=80,pass=-1,bal=0.002491},
            type=h,
            vert=80,
            rat=0.8
        }
    )
}

Given that this information was written in 2008, this example strategy will unlikely work as-is with the more recent Scotch versions. Therefore, the steps for getting the current default strategy from within Scotch, is to do the following steps:

Edit the file system/decomposeParDict and use the following settings:
```
method          scotch;

scotchCoeffs
{
    writeGraph true;
}
```
Run decomposePar. For example, it will write a file named region0.grf.
Now, instead of using gmap, run gpart with the following command structure to get the default strategy:
```
gpart \<nProcs\> -vs \<grfFile\>
```
where:
- <grfFile> is the file that was obtained with the option writeGraph=true, namely region0.grf.
- <nProcs> is the numberOfSubdomains defined in the dictionary file.
At the end of the execution will be shown a long string, similar to the following example (complete line was cropped at [...]):
```
S    Strat=m{asc=b{width=3,bnd=d{pass=40,dif=1,rem=0}[...],type=h}
```

Edit the file system/decomposeParDict once again and add the strategy entry as exemplified:

method          scotch;

scotchCoeffs
{
    //writeGraph true;
    strategy "m{asc=b{width=3,bnd=d{pass=40,dif=1,rem=0}[...],type=h}";
}

Finally, run decomposePar once again, to at least test if it works as intended.

Note: gpart can be found in the current search path by adding the respective bin folder from the Scotch installation, namely by running the following commands:

source $(foamEtcFile config.sh/scotch)
export PATH=$PATH:$SCOTCH_ARCH_PATH/bin

Source files

Definition at line 226 of file scotchDecomp.H.

Constructor & Destructor Documentation

◆ scotchDecomp() [1/2]

scotchDecomp ( const scotchDecomp & )

protecteddelete

◆ scotchDecomp() [2/2]

scotchDecomp	(	const dictionary &	decompDict,
		const word &	regionName = `""`
	)

explicit

Definition at line 71 of file dummyScotchDecomp.C.

◆ ~scotchDecomp()

virtual ~scotchDecomp ( )

virtualdefault

Member Function Documentation

◆ decomposeSerial()

Foam::label decomposeSerial	(	const labelList &	adjncy,
		const labelList &	xadj,
		const List< scalar > &	cWeights,
		labelList &	decomp
	)		const

protectedvirtual

Implements metisLikeDecomp.

Definition at line 53 of file dummyScotchDecomp.C.

References Foam::exit(), Foam::FatalError, FatalErrorInFunction, Foam::nl, and notImplementedMessage.

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◆ operator=()

void operator= ( const scotchDecomp & )

protecteddelete

◆ TypeName()

TypeName ( "scotch" )

◆ parallelAware()

virtual bool parallelAware ( ) const

inlinevirtual

Implements decompositionMethod.

Definition at line 280 of file scotchDecomp.H.

◆ decompose() [1/13]

Foam::labelList decompose	(	const polyMesh &	mesh,
		const pointField &	points,
		const scalarField &	pointWeights
	)		const

virtual

Reimplemented from metisLikeDecomp.

Definition at line 83 of file dummyScotchDecomp.C.

References Foam::exit(), Foam::FatalError, FatalErrorInFunction, and notImplementedMessage.

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◆ decompose() [2/13]

Foam::labelList decompose	(	const polyMesh &	mesh,
		const labelList &	agglom,
		const pointField &	regionPoints,
		const scalarField &	regionWeights
	)		const

virtual

Reimplemented from metisLikeDecomp.

Definition at line 97 of file dummyScotchDecomp.C.

References Foam::exit(), Foam::FatalError, FatalErrorInFunction, and notImplementedMessage.

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◆ decompose() [3/13]

Foam::labelList decompose	(	const labelListList &	globalCellCells,
		const pointField &	cc,
		const scalarField &	cWeights
	)		const

virtual

Reimplemented from metisLikeDecomp.

Definition at line 112 of file dummyScotchDecomp.C.

References Foam::exit(), Foam::FatalError, FatalErrorInFunction, and notImplementedMessage.

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◆ decompose() [4/13]

Foam::labelList decompose

Definition at line 1318 of file decompositionMethod.C.

◆ decompose() [5/13]

Foam::labelList decompose

Definition at line 1329 of file decompositionMethod.C.

◆ decompose() [6/13]

virtual labelList decompose

◆ decompose() [7/13]

Foam::labelList decompose

Definition at line 377 of file decompositionMethod.C.

◆ decompose() [8/13]

Foam::labelList decompose

Definition at line 389 of file decompositionMethod.C.

◆ decompose() [9/13]

Foam::labelList decompose

Definition at line 430 of file decompositionMethod.C.

◆ decompose() [10/13]

virtual labelList decompose

◆ decompose() [11/13]

Foam::labelList decompose

Definition at line 449 of file decompositionMethod.C.

◆ decompose() [12/13]

Foam::labelList decompose

Definition at line 860 of file decompositionMethod.C.

◆ decompose() [13/13]

Foam::labelList decompose

Definition at line 1264 of file decompositionMethod.C.

The documentation for this class was generated from the following files:

src/parallel/decompose/scotchDecomp/scotchDecomp.H
src/dummyThirdParty/scotchDecomp/dummyScotchDecomp.C
src/parallel/decompose/scotchDecomp/scotchDecomp.C

Public Member Functions

Protected Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ scotchDecomp() [1/2]

◆ scotchDecomp() [2/2]

◆ ~scotchDecomp()

Member Function Documentation

◆ decomposeSerial()

◆ operator=()

◆ TypeName()

◆ parallelAware()

◆ decompose() [1/13]

◆ decompose() [2/13]

◆ decompose() [3/13]

◆ decompose() [4/13]

◆ decompose() [5/13]

◆ decompose() [6/13]

◆ decompose() [7/13]

◆ decompose() [8/13]

◆ decompose() [9/13]

◆ decompose() [10/13]

◆ decompose() [11/13]

◆ decompose() [12/13]

◆ decompose() [13/13]