[petsc-dev] The question about MatNullSpaceSetFunction()

[Matthew Knepley]

On Wed, Apr 1, 2015 at 4:39 AM, Lulu Liu <lulu.liu at kaust.edu.sa> wrote:

> I feel confused about  MatNullSpaceSetFunction(), and is there any
> example to show how to use this function? What should I do in the the
> following function* rem?*
> For example, I have a vection a=(a1,a2,a3) and the null space is (0,0,1).
>

Your function should remove the null space. Thus, if you got that input,
you would return (a1,a2,0)

  Matt


> PetscErrorCode MatNullSpaceSetFunction(MatNullSpace sp, PetscErrorCode
> (*rem)(MatNullSpace,Vec,void*),void *ctx)
>
> Input Parameters*sp*- the null space object*rem*- the function that
> removes the null space
> *ctx*- context for the remove function
>
>
>
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