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faceEdges

Find edges belonging to specified faces

Since R2021a

    Description

    example

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

    example

    EdgeID = faceEdges(g,RegionID,FilterType) returns internal, external, or all edges belonging 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 belonging 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 object. The axes object contains 6 objects of type quiver, text, patch, line.

    Find edges belonging 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 object. The axes object contains 6 objects of type quiver, text, patch, line.

    Find edges belonging 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 object. The axes object contains 4 objects of type line, text.

    Find edges belonging 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 object. The axes object contains 11 objects of type line, text.

    Find edges belonging 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 object. The axes object contains 6 objects of type quiver, text, patch, line.

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

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

    From all edges belonging to that face, return the edges belonging 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 belonging to that face, return the edges belonging 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 object. The axes object contains 6 objects of type quiver, text, patch, line.

    Input Arguments

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    Geometry, specified as an fegeometry object, a DiscreteGeometry object, or an 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 belonging to only internal faces. Internal faces are faces shared between multiple cells.

    • "external" — Edges belonging to only external faces. External faces are faces not shared between multiple cells.

    • "all" — All edges belonging to the specified cells.

    Output Arguments

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

    Version History

    Introduced in R2021a

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