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multicylinder

Create geometry formed by several cylindrical cells

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Syntax

gm = multicylinder(R,H)
gm = multicylinder(R,H,Name,Value)

Description

example

gm = multicylinder(R,H) creates a geometry by combining several cylindrical cells.

When creating each cylinder, multicylinder uses the following coordinate system.

Cylinder in x, y, z coordinates with its base in the x-y plane and the center of its base at the origin

example

gm = multicylinder(R,H,Name,Value) creates a multi-cylinder geometry using one or more Name,Value pair arguments.

Examples

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Open Live Script

Create a geometry that consists of three nested cylinders of the same height and include this geometry in a PDE model.

Create the geometry by using the multicylinder function. The resulting geometry consists of three cells.

gm = multicylinder([5 10 15],2)
gm = 
  DiscreteGeometry with properties:

       NumCells: 3
       NumFaces: 9
       NumEdges: 6
    NumVertices: 6
       Vertices: [6x3 double]

Create a PDE model.

model = createpde
model = 
  PDEModel with properties:

           PDESystemSize: 1
         IsTimeDependent: 0
                Geometry: []
    EquationCoefficients: []
      BoundaryConditions: []
       InitialConditions: []
                    Mesh: []
           SolverOptions: [1x1 pde.PDESolverOptions]

Include the geometry in the model.

model.Geometry = gm
model = 
  PDEModel with properties:

           PDESystemSize: 1
         IsTimeDependent: 0
                Geometry: [1x1 DiscreteGeometry]
    EquationCoefficients: []
      BoundaryConditions: []
       InitialConditions: []
                    Mesh: []
           SolverOptions: [1x1 pde.PDESolverOptions]

Plot the geometry.

pdegplot(model,"CellLabels","on","FaceAlpha",0.5)

Figure contains an axes object. The axes object contains 6 objects of type quiver, text, patch, line.

Open Live Script

Create a geometry that consists of three stacked cylinders and include this geometry in a PDE model.

Create the geometry by using the multicylinder function with the ZOffset argument. The resulting geometry consists of four cells stacked on top of each other.

gm = multicylinder(10,[1 2 3 4],"ZOffset",[0 1 3 6])
gm = 
  DiscreteGeometry with properties:

       NumCells: 4
       NumFaces: 9
       NumEdges: 5
    NumVertices: 5
       Vertices: [5x3 double]

Create a PDE model.

model = createpde
model = 
  PDEModel with properties:

           PDESystemSize: 1
         IsTimeDependent: 0
                Geometry: []
    EquationCoefficients: []
      BoundaryConditions: []
       InitialConditions: []
                    Mesh: []
           SolverOptions: [1x1 pde.PDESolverOptions]

Include the geometry in the model.

model.Geometry = gm
model = 
  PDEModel with properties:

           PDESystemSize: 1
         IsTimeDependent: 0
                Geometry: [1x1 DiscreteGeometry]
    EquationCoefficients: []
      BoundaryConditions: []
       InitialConditions: []
                    Mesh: []
           SolverOptions: [1x1 pde.PDESolverOptions]

Plot the geometry.

pdegplot(model,"CellLabels","on","FaceAlpha",0.5)

Figure contains an axes object. The axes object contains 6 objects of type quiver, text, patch, line.

Open Live Script

Create a geometry that consists of a single cylinder and include this geometry in a PDE model.

Use the multicylinder function to create a single cylinder. The resulting geometry consists of one cell.

gm = multicylinder(5,10)
gm = 
  DiscreteGeometry with properties:

       NumCells: 1
       NumFaces: 3
       NumEdges: 2
    NumVertices: 2
       Vertices: [2x3 double]

Create a PDE model.

model = createpde
model = 
  PDEModel with properties:

           PDESystemSize: 1
         IsTimeDependent: 0
                Geometry: []
    EquationCoefficients: []
      BoundaryConditions: []
       InitialConditions: []
                    Mesh: []
           SolverOptions: [1x1 pde.PDESolverOptions]

Include the geometry in the model.

model.Geometry = gm
model = 
  PDEModel with properties:

           PDESystemSize: 1
         IsTimeDependent: 0
                Geometry: [1x1 DiscreteGeometry]
    EquationCoefficients: []
      BoundaryConditions: []
       InitialConditions: []
                    Mesh: []
           SolverOptions: [1x1 pde.PDESolverOptions]

Plot the geometry.

pdegplot(model,"CellLabels","on")

Figure contains an axes object. The axes object contains 6 objects of type quiver, text, patch, line.

Open Live Script

Create a hollow cylinder and include it as a geometry in a PDE model.

Create a hollow cylinder by using the multicylinder function with the Void argument. The resulting geometry consists of one cell.

gm = multicylinder([9 10],10,"Void",[true,false])
gm = 
  DiscreteGeometry with properties:

       NumCells: 1
       NumFaces: 4
       NumEdges: 4
    NumVertices: 4
       Vertices: [4x3 double]

Create a PDE model.

model = createpde
model = 
  PDEModel with properties:

           PDESystemSize: 1
         IsTimeDependent: 0
                Geometry: []
    EquationCoefficients: []
      BoundaryConditions: []
       InitialConditions: []
                    Mesh: []
           SolverOptions: [1x1 pde.PDESolverOptions]

Include the geometry in the model.

model.Geometry = gm
model = 
  PDEModel with properties:

           PDESystemSize: 1
         IsTimeDependent: 0
                Geometry: [1x1 DiscreteGeometry]
    EquationCoefficients: []
      BoundaryConditions: []
       InitialConditions: []
                    Mesh: []
           SolverOptions: [1x1 pde.PDESolverOptions]

Plot the geometry.

pdegplot(model,"CellLabels","on","FaceAlpha",0.5)

Figure contains an axes object. The axes object contains 6 objects of type quiver, text, patch, line.

Input Arguments

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Cell radius, specified as a positive real number or a vector of positive real numbers. If R is a vector, then R(i) specifies the radius of the ith cell.

Radius R and height H can be scalars or vectors of the same length. For a combination of scalar and vector inputs, multicylinder replicates the scalar arguments into vectors of the same length.

Note

Either radius or height must be the same for all cells in the geometry.

Example: gm = multicylinder([1 2 3],1)

Cell height, specified as a positive real number or a vector of positive real numbers. If H is a vector, then H(i) specifies the height of the ith cell.

Radius R and height H can be scalars or vectors of the same length. For a combination of scalar and vector inputs, multicylinder replicates the scalar arguments into vectors of the same length.

Note

Either radius or height must be the same for all cells in the geometry.

Example: gm = multicylinder(1,[1 2 3],"Zoffset",[0 1 3])

Name-Value Arguments

Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Before R2021a, use commas to separate each name and value, and enclose Name in quotes.

Example: gm = multicylinder([1 2],1,"Void",[true,false])

Z-offset for each cell, specified as a vector of real numbers. ZOffset(i) specifies the Z-offset of the ith cell. This vector must have the same length as the radius vector R or height vector H.

Note

The ZOffset argument is valid only if the radius is the same for all cells in the geometry.

Example: gm = multicylinder(20,[10 10],"ZOffset",[0 10])

Data Types: double

Empty cell indicator, specified as a vector of logical true or false values. This vector must have the same length as the radius vector R or the height vector H.

The value true corresponds to an empty cell. By default, multicylinder assumes that all cells are not empty.

Example: gm = multicylinder([1 2],1,"Void",[true,false])

Data Types: double

Output Arguments

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Geometry object, returned as a DiscreteGeometry object.

Tip

A cylinder has one cell, three faces, and two edges. Also, since every edge has a start and an end vertex, a cylinder has vertices. Both edges are circles, their start and end vertices coincide. Thus, a cylinder has two vertices - one for each edge.

Limitations

  • multicylinder lets you create only geometries consisting of stacked or nested cylinders. For nested cylinders, the height must be the same for all cells in the geometry. For stacked cylinders, the radius must be the same for all cells in the geometry. Use the ZOffset argument to stack the cells on top of each over without overlapping them.

  • multicylinder does not let you create nested cylinders of the same radius. The call multicylinder(r,[h1,h2,...]) is not supported.

Version History

Introduced in R2017a

See Also

Functions

Objects