# applyBoundaryCondition

Add boundary condition to `PDEModel`

container

## Syntax

## Description

`applyBoundaryCondition(`

adds a Dirichlet boundary condition to `model`

,"dirichlet",`RegionType`

,`RegionID`

,`Name,Value`

)`model`

. The boundary
condition applies to boundary regions of type `RegionType`

with
ID numbers in `RegionID`

, and with arguments
`r`

, `h`

, `u`

,
`EquationIndex`

specified in the
`Name,Value`

pairs. For Dirichlet boundary conditions,
specify either both arguments `r`

and `h`

, or
the argument `u`

. When specifying `u`

, you can
also use `EquationIndex`

.

`applyBoundaryCondition(`

adds a Neumann boundary condition to `model`

,"neumann",`RegionType`

,`RegionID`

,`Name,Value`

)`model`

. The boundary
condition applies to boundary regions of type `RegionType`

with
ID numbers in `RegionID`

, and with values `g`

and `q`

specified in the `Name,Value`

pairs.

`applyBoundaryCondition(`

adds an individual boundary condition for each equation in a system of PDEs. The
boundary condition applies to boundary regions of type
`model`

,"mixed",`RegionType`

,`RegionID`

,`Name,Value`

)`RegionType`

with ID numbers in
`RegionID`

, and with values specified in the
`Name,Value`

pairs. For mixed boundary conditions, you can use
`Name,Value`

pairs from both Dirichlet and Neumann boundary
conditions as needed.

returns the boundary condition object.`bc`

= applyBoundaryCondition(___)

## Examples

## Input Arguments

## Output Arguments

## Tips

When there are multiple boundary condition assignments to the same geometric region, the toolbox uses the last applied setting.

To avoid assigning boundary conditions to a wrong region, ensure that you are using the correct geometric region IDs by plotting and visually inspecting the geometry.

If you do not specify a boundary condition for an edge or face, the default is the Neumann boundary condition with the zero values for

`"g"`

and`"q"`

.

## Version History

**Introduced in R2015a**