findCoefficients

Locate active PDE coefficients

Syntax

CA = findCoefficients(coeffs,RegionType,RegionID)

Description

CA = findCoefficients(coeffs,RegionType,RegionID) returns the active coefficient assignment CA for the coefficients in the specified region.

Examples

Find the Active Coefficients for a Region

Create a PDE model that has a few subdomains.

model = createpde();
geometryFromEdges(model,@lshapeg);
pdegplot(model,"FaceLabels","on")
ylim([-1.1,1.1])
axis equal

Set coefficients on each pair of regions.

specifyCoefficients(model,"m",0,"d",0,"c",12,"a",0,"f",1,"Face",[1,2]);
specifyCoefficients(model,"m",0,"d",0,"c",13,"a",0,"f",2,"Face",[1,3]);
specifyCoefficients(model,"m",0,"d",0,"c",23,"a",0,"f",3,"Face",[2,3]);

Check the coefficient specification for region 1.

coeffs = model.EquationCoefficients;
ca = findCoefficients(coeffs,"Face",1)

ca = 
  CoefficientAssignment with properties:

    RegionType: 'face'
      RegionID: [1 3]
             m: 0
             d: 0
             c: 13
             a: 0
             f: 2

Input Arguments

coeffs — Model coefficients

EquationCoefficients property of a PDE model

Model coefficients, specified as the EquationCoefficients property of a PDE model. Coefficients can be complex numbers.

Example: model.EquationCoefficients

RegionType — Geometric region type

"Face" for a 2-D model | "Cell" for a 3-D model

Geometric region type, specified as "Face" for a 2-D model, or "Cell" for a 3-D model.

Example: ca = findCoefficients(coeffs,"Face",[1,3])

Data Types: char | string

RegionID — Region ID

vector of positive integers

Region ID, specified as a vector of positive integers. View the subdomain labels for a 2-D model using pdegplot(model,"FaceLabels","on"). Currently, there are no subdomains for 3-D models, so the only acceptable value for a 3-D model is 1.

Example: ca = findCoefficients(coeffs,"Face",[1,3])

Data Types: double

Output Arguments

CA — Coefficient assignment

CoefficientAssignment object

Coefficient assignment, returned as a CoefficientAssignment Properties object.

Version History

Introduced in R2016a