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faceEdges

Find edges attached to specified faces

    Description

    example

    EdgeID = faceEdges(g,RegionID) finds edges attached to the faces with ID numbers listed in RegionID.

    example

    EdgeID = faceEdges(g,RegionID,FilterType) returns internal, external, or all edges attached to the faces with ID numbers listed in RegionID. This syntax is valid for 3-D geometries only.

    Examples

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    Find edges attached to the top and bottom faces of a block.

    Create a block geometry.

    gm = multicuboid(3,2,1)
    gm = 
      DiscreteGeometry with properties:
    
           NumCells: 1
           NumFaces: 6
           NumEdges: 12
        NumVertices: 8
           Vertices: [8x3 double]
    
    

    Plot the geometry with the face labels.

    pdegplot(gm,'FaceLabels','on','FaceAlpha',0.2)

    Figure contains an axes. The axes contains 3 objects of type quiver, patch, line.

    Find edges attached to faces 1 and 2.

    edgeIDs = faceEdges(gm,[1 2])
    edgeIDs = 1×8
    
         1     2     3     4     5     6     7     8
    
    

    Plot the geometry with the edge labels.

    figure
    pdegplot(gm,'EdgeLabels','on','FaceAlpha',0.2)

    Figure contains an axes. The axes contains 3 objects of type quiver, patch, line.

    Find edges attached to two faces of the L-shaped membrane.

    Create a model and include this geometry. The geometry of the L-shaped membrane is described in the file lshapeg.

    model = createpde();
    gm = geometryFromEdges(model,@lshapeg)
    gm = 
      AnalyticGeometry with properties:
    
           NumCells: 0
           NumFaces: 3
           NumEdges: 10
        NumVertices: 8
           Vertices: [8x2 double]
    
    

    Plot the geometry with the face labels.

    pdegplot(gm,'FaceLabels','on')

    Figure contains an axes. The axes contains 4 objects of type line, text.

    Find edges attached to faces 1 and 2.

    edgeIDs = faceEdges(gm,[1 2])
    edgeIDs = 1×8
    
         1     2     3     6     7     8     9    10
    
    

    Plot the geometry with the edge labels.

    figure
    pdegplot(gm,'EdgeLabels','on')

    Figure contains an axes. The axes contains 11 objects of type line, text.

    Find edges attached to the side face of the inner cuboid in a geometry consisting of two nested cuboids.

    Create a geometry that consists of two nested cuboids of the same height.

    gm = multicuboid([2 5],[4 10],3)
    gm = 
      DiscreteGeometry with properties:
    
           NumCells: 2
           NumFaces: 12
           NumEdges: 24
        NumVertices: 16
           Vertices: [16x3 double]
    
    

    Plot the geometry with the face labels.

    pdegplot(gm,'FaceLabels','on','FaceAlpha',0.2)

    Figure contains an axes. The axes contains 3 objects of type quiver, patch, line.

    Find all edges attached to the side face of the inner cuboid.

    edgeIDs = faceEdges(gm,6)
    edgeIDs = 1×4
    
         1     5    10    12
    
    

    From all edges attached to that face, return the edges attached to only the internal faces. Internal faces are faces shared between multiple cells.

    edgeIDs = faceEdges(gm,6,'internal')
    edgeIDs = 1×2
    
        10    12
    
    

    From all edges attached to that face, return the edges attached to the external faces.

    edgeIDs = faceEdges(gm,6,'external')
    edgeIDs = 1×2
    
         1     5
    
    

    Plot the geometry with the edge labels.

    pdegplot(gm,'EdgeLabels','on','FaceAlpha',0.2)

    Figure contains an axes. The axes contains 3 objects of type quiver, patch, line.

    Input Arguments

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    Geometry, specified as a DiscreteGeometry or AnalyticGeometry object.

    Face ID, specified as a positive number or a vector of positive numbers. Each number represents a face ID.

    Type of edges to return, specified as 'internal', 'external', or 'all'. Depending on this argument, faceEdges returns these types of faces for a 3-D geometry:

    • 'internal' — Edges attached to only internal faces. Internal faces are faces shared between multiple cells.

    • 'external' — Edges attached to only external faces. External faces are faces not shared between multiple cells.

    • 'all' — All edges attached to the specified cells.

    Output Arguments

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    IDs of edges attached to the specified faces, returned as a positive number or a vector of positive numbers.

    Introduced in R2021a