facesAttachedToEdges

Find faces attached to specified edges

Since R2021a

Syntax

FaceID = facesAttachedToEdges(g,RegionID)

FaceID = facesAttachedToEdges(g,RegionID,FilterType)

Description

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

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

Examples

Faces Attached to Specified Edges of 3-D Geometry

Find faces attached to particular edges 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 edge labels.

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

Find faces attached to edges 1, 2, and 5.

faceIDs = facesAttachedToEdges(gm,[1 2 5])

faceIDs = 1×4

     1     2     5     6

Plot the geometry with the face labels.

figure
pdegplot(gm,"FaceLabels","on","FaceAlpha",0.2)

Faces Attached to Specified Edges of 2-D Geometry

Find faces attached to particular edges 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 edge labels.

pdegplot(gm,"EdgeLabels","on")

Find faces attached to edges 7 and 10.

faceIDs = facesAttachedToEdges(gm,[7 10])

faceIDs = 1×2

     1     2

Plot the geometry with the face labels.

figure
pdegplot(gm,"FaceLabels","on")

Internal and External Faces Attached to Specified Edges

Find internal and external faces attached to the edges 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 edge labels.

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

Find all faces attached to the top edges of the inner cuboid.

facesAttachedToEdges(gm,[5:8])

ans = 1×6

     2     3     4     5     6    12

Find only the internal faces attached to the top edges of the inner cuboid. Internal faces are faces shared between multiple cells.

facesAttachedToEdges(gm,[5:8],"internal")

ans = 1×4

     3     4     5     6

Find only the external faces attached to the top edges of the inner cuboid.

facesAttachedToEdges(gm,[5:8],"external")

ans = 1×2

     2    12

Plot the geometry with the face labels.

figure
pdegplot(gm,"FaceLabels","on","FaceAlpha",0.2)

Input Arguments

g — Geometry

fegeometry object | DiscreteGeometry object | AnalyticGeometry object

Geometry, specified as an fegeometry object, a DiscreteGeometry object, or an AnalyticGeometry object.

RegionID — Edge ID

positive number | vector of positive numbers

Edge ID, specified as a positive number or a vector of positive numbers. Each number represents an edge ID.

FilterType — Type of faces to return

"all" (default) | "internal" | "external"

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

• "internal" — Internal faces, that is, faces shared between multiple cells.

• "external" — External faces, that is, faces not shared between multiple cells.

• "all" — All faces attached to the specified cells.

Output Arguments

FaceID — IDs of faces attached to specified edges

positive number | vector of positive numbers

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

Version History

Introduced in R2021a

R2023a: Finite element model

facesAttachedToEdges now accepts geometries specified by fegeometry objects.