cellFaces

Find faces belonging to specified cells

Since R2021a

Syntax

FaceID = cellFaces(g,RegionID)

FaceID = cellFaces(g,RegionID,FilterType)

Description

FaceID = cellFaces(g,RegionID) finds faces belonging to the cells with ID numbers listed in RegionID.

FaceID = cellFaces(g,RegionID,FilterType) returns internal, external, or all faces belonging to the cells with ID numbers listed in RegionID.

Examples

Faces Belonging to Specified Cells

Find faces belonging to two cuboids in a geometry consisting of four stacked cuboids.

Create a geometry that consists of four stacked cuboids.

gm = multicuboid(5,10,[1 2 3 4],"ZOffset",[0 1 3 6])

gm = 
  DiscreteGeometry with properties:

       NumCells: 4
       NumFaces: 21
       NumEdges: 36
    NumVertices: 20
       Vertices: [20x3 double]

Plot the geometry with the cell labels.

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

Find faces belonging to cells 1 and 3.

faceIDs = cellFaces(gm,[1 3])

faceIDs = 1×12

     1     2     3     4     5     6     7    12    13    14    15    16

Plot the geometry with the face labels.

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

Internal and External Faces Belonging to Specified Cells

Find faces belonging to the outer 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 cell labels.

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

Find all faces belonging to the outer cell.

faceIDs = cellFaces(gm,2)

faceIDs = 1×10

     3     4     5     6     7     8     9    10    11    12

Find only the internal faces belonging to the outer cell. Internal faces are faces shared between multiple cells.

faceIDs_int = cellFaces(gm,2,"internal")

faceIDs_int = 1×4

     3     4     5     6

Find only the external faces belonging to the outer cell.

faceIDs_ext = cellFaces(gm,2,"external")

faceIDs_ext = 1×6

     7     8     9    10    11    12

Plot the geometry with the face labels.

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

Input Arguments

g — 3-D geometry

fegeometry object | DiscreteGeometry object

3-D geometry, specified as an fegeometry object or a DiscreteGeometry object. See fegeometry and DiscreteGeometry Properties

RegionID — Cell ID

positive number | vector of positive numbers

Cell ID, specified as a positive number or a vector of positive numbers. Each number represents a cell 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, cellFaces returns these types of faces:

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

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

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

Output Arguments

FaceID — IDs of faces belonging to specified cells

positive number | vector of positive numbers

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

Version History

Introduced in R2021a

R2023a: Finite element model

cellFaces now accepts geometries specified by fegeometry objects.