faceEdges

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)

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)

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")

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")

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)

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)