Assemble the boundary condition matrices for an elliptic PDE.

The PDE is Poisson's equation,

Partial Differential Equation Toolbox™ solves equations of the form

So, represent Poisson's equation in toolbox syntax by setting `c`

= 1, `a`

= 0, and `f`

= 1.

Create a PDE model container. Import the `ForearmLink.stl`

file into the model and examine the geometry.

Set zero Dirichlet boundary conditions on the narrow faces (numbered 1 through 4).

Set a Neumann condition with `g`

= -1 on face 6, and `g`

= 1 on face 5.

Create a mesh for the model.

Create the boundary condition matrices for the model.

The `H`

matrix is quite sparse. The `Q`

matrix has no nonzero entries.

Fraction of nonzero entries in H is 3.4709e-05
Number of nonzero entries in Q is 0