[petsc-dev] [petsc-users] Is there a way to do row/column scaling of jacobian matrix

[Barry Smith]

   We should write a FAQ question that addresses all theses issues. I admit I don't really want to add these scalings to PETSc it makes the code more complicated, unless we really need it.

    Barry

On Apr 5, 2011, at 1:24 AM, Jed Brown wrote:

> On Tue, Apr 5, 2011 at 06:10, Barry Smith <bsmith at mcs.anl.gov> wrote:
> They are done to change the relative importance of different entries in the vector to determine stopping conditions and search directions in Newton's method.
> 
> Note that weighting fields differently is equivalent to choosing units for the different fields. I think it is generally a good idea to make the units a runtime option anyway since it lets you check that the code is dimensionally correct.