[petsc-users] Scale the diagonal entries of a Mat

[Hui Zhang]

On Feb 23, 2013, at 1:32 PM, Jed Brown wrote:

> Add big values to diagonal entries and scale the right hand side appropriately, as per the definition. It is a terrible method.

Why?  That is what I was taught by textbooks and used by some FEM library like FreeFem++.

> 
> On Feb 23, 2013 6:29 AM, "Hui Zhang" <mike.hui.zhang at hotmail.com> wrote:
> I want to implement diagonal penalty method for enforcing the Dirichlet boundary conditions.  That is, the diagonal entries corresponding to Dirichlet boundary are going to be scaled by a large number.
> 
> What is the easiest way to do this?  Thanks!