CoefficientAssignment Properties

Coefficient assignments

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A CoefficientAssignment object contains a description of the PDE coefficients. A PDEModel container has a vector of CoefficientAssignment objects in its EquationCoefficients.CoefficientAssignments property.

Coefficients are the m, d, c, a, and f variables in the PDE

$m \frac{\partial^{2} u}{\partial t^{2}} + d \frac{\partial u}{\partial t} - \nabla \cdot (c \nabla u) + a u = f$

or the eigenvalue problem

$\begin{array}{l} - \nabla \cdot (c \nabla u) + a u = λ d u \\ or \\ - \nabla \cdot (c \nabla u) + a u = λ^{2} m u \end{array}$

Create coefficients for your model using the specifyCoefficients function.

Properties

`RegionType` — Region type
`'face'` | `'cell'`

Region type, specified as 'face' for a 2-D region, or 'cell' for a 3-D region.

Data Types: char | string

`RegionID` — Region ID
vector of positive integers

Region ID, specified as a vector of positive integers. To determine which ID corresponds to which portion of the geometry, use the pdegplot function. Set the 'FaceLabels' name-value pair to 'on'.

Data Types: double

`m` — Second-order time derivative coefficient
scalar | column vector | function handle

Second-order time derivative coefficient, specified as a scalar, column vector, or function handle. For details of the m coefficient specification, see m, d, or a Coefficient for specifyCoefficients.

Data Types: double | function_handle
Complex Number Support: Yes

`d` — First-order time derivative coefficient
scalar | column vector | function handle

First-order time derivative coefficient, specified as a scalar, column vector, or function handle. For details of the d coefficient specification, see m, d, or a Coefficient for specifyCoefficients.

Data Types: double | function_handle
Complex Number Support: Yes

`c` — Second-order space derivative coefficient
scalar | column vector | function handle

Second-order space derivative coefficient, specified as a scalar, column vector, or function handle. For details of the c coefficient specification, see c Coefficient for specifyCoefficients.

Data Types: double | function_handle
Complex Number Support: Yes

`a` — Solution multiplier coefficient
scalar | column vector | function handle

Solution multiplier coefficient, specified as a scalar, column vector, or function handle. For details of the a coefficient specification, see m, d, or a Coefficient for specifyCoefficients.

Data Types: double | function_handle
Complex Number Support: Yes

`f` — Source coefficient
scalar | column vector | function handle

Source coefficient, specified as a scalar, column vector, or function handle. For details of the f coefficient specification, see f Coefficient for specifyCoefficients.

Data Types: double | function_handle
Complex Number Support: Yes

Version History

Introduced in R2016a

See Also

findCoefficients | specifyCoefficients

Topics

Solve Problems Using PDEModel Objects