[aspect-devel] Linear solver A block tolerance & Linear solver S block tolerance ?

[Wolfgang Bangerth]

On 04/24/2017 05:30 PM, Shangxin Liu wrote:
> Hi Timo,
>
> This may be unrelated to our alpha vs gravity discussion. But there are two
> new Global parameters I have no idea about their function:
>
> Linear solver A block tolerance and Linear solver S block tolerance.
>
> What are their mathematic meanings and functions, compared to linear solver
> tolerance?

They are discussed here (with corresponding entries in the manual):

https://github.com/geodynamics/aspect/blob/master/source/simulator/parameters.cc#L269

They correspond to the precondition that is discussed in the Kronbichler et 
al. paper.

Best
  Wolfgang

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Wolfgang Bangerth          email:                 bangerth at colostate.edu
                            www: http://www.math.colostate.edu/~bangerth/