Cell ID on Neighbouring Processor Patches

maHein · September 21, 2019, 15:48

Hello,

I wrote an algorithm, which has to be adjusted for parallel computing. For this, I need the cell ID of both sides of a processor patch. For the current patch, this can simply be achieved by a loop over all faces and a faceCells() command. However, I am struggling to get access to the neighbouring patch. My progress so far:

Code:

    // Loop over all patches
    forAll(mesh_.boundary(), patchI)
    {
        // Current patch
        const fvPatch& pPatch = mesh_.boundary()[patchI];

        // Check, if patch is coupled, e.g. processor patch
        if (pPatch.coupled())
        {
            // Loop over all faces of given patch
            forAll(pPatch, faceI)
            {
                // ID of cell connected to faceI on current patch
                label cellI_own = mesh_.boundary()[patchI].faceCells()[faceI];

                // How to get the corresponding cellI_nei
                // of neighbouring processor patch?
                label cellI_nei = ?
            }
        }
    }

At this point I am missing the connection of current processor patch and its neighbour patch on the next processor. If I need to access specific fields, I could use either patchInternalField() or patchNeighbourField(). However, I want to have the direct face or cell ID.

Thanks for your help!

Martin

sxpsxp007 · November 19, 2020, 06:06

Hi Martin,

Have you solved it? I am meeting the similar problem as yours.

olesen · November 27, 2020, 14:17

Maybe this?
globalIndex with number of cells, a flat boundary field, fill with patchCells (offset by localStart) and syncTools swapBoundary?

theBananaTrick · March 23, 2022, 12:44

Hi,
I am also very interested in this! Where you able to fulfil this task?

@Olesen would swapBoundaryCellList be a good place to start?

September 21, 2019, 15:48	Cell ID on Neighbouring Processor Patches	#1
maHein Member Join Date: Jun 2012 Posts: 76 Rep Power: 13	Hello, I wrote an algorithm, which has to be adjusted for parallel computing. For this, I need the cell ID of both sides of a processor patch. For the current patch, this can simply be achieved by a loop over all faces and a faceCells() command. However, I am struggling to get access to the neighbouring patch. My progress so far: Code: // Loop over all patches forAll(mesh_.boundary(), patchI) { // Current patch const fvPatch& pPatch = mesh_.boundary()[patchI]; // Check, if patch is coupled, e.g. processor patch if (pPatch.coupled()) { // Loop over all faces of given patch forAll(pPatch, faceI) { // ID of cell connected to faceI on current patch label cellI_own = mesh_.boundary()[patchI].faceCells()[faceI]; // How to get the corresponding cellI_nei // of neighbouring processor patch? label cellI_nei = ? } } } At this point I am missing the connection of current processor patch and its neighbour patch on the next processor. If I need to access specific fields, I could use either patchInternalField() or patchNeighbourField(). However, I want to have the direct face or cell ID. Thanks for your help! Martin the_ichthyologist likes this.

November 19, 2020, 06:06	Cell ID on Neighbouring Processor Patches	#2
sxpsxp007 New Member Shang Join Date: Jan 2018 Posts: 5 Rep Power: 8	Hi Martin, Have you solved it? I am meeting the similar problem as yours.

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November 27, 2020, 14:17		#3
olesen Senior Member Mark Olesen Join Date: Mar 2009 Location: https://olesenm.github.io/ Posts: 1,685 Rep Power: 40	Maybe this? globalIndex with number of cells, a flat boundary field, fill with patchCells (offset by localStart) and syncTools swapBoundary?

March 23, 2022, 12:44		#4
theBananaTrick New Member Join Date: Feb 2022 Posts: 25 Rep Power: 4	Hi, I am also very interested in this! Where you able to fulfil this task? @Olesen would swapBoundaryCellList be a good place to start?