[petsc-dev] [petsc-users] FETI-DP

2011-05-04 Thread Thomas Witkowski
Jed Brown wrote: > On Wed, Apr 20, 2011 at 17:15, Thomas Witkowski > > wrote: > > They really can't because sometimes the Lagrange multiplier > itself will be stored on a different process. Also, this > representation has lots of e

[petsc-dev] [petsc-users] FETI-DP

2011-04-20 Thread Jed Brown
On Wed, Apr 20, 2011 at 17:15, Thomas Witkowski < thomas.witkowski at tu-dresden.de> wrote: > They really can't because sometimes the Lagrange multiplier itself will be >> stored on a different process. Also, this representation has lots of empty >> rows where as storing B, every row has entries (

[petsc-dev] [petsc-users] FETI-DP

2011-04-20 Thread Thomas Witkowski
Jed Brown wrote: > By the way, you should definitely read Klawonn and Rheinbach's > "Inexact FETI-DP methods" > (http://onlinelibrary.wiley.com/doi/10.1002/nme.1758/pdf , ask me if > you don't have access). I think it has the most clear description of > what is going on, and offers the most fle

[petsc-dev] [petsc-users] FETI-DP

2011-04-20 Thread Thomas Witkowski
Jed Brown wrote: > On Wed, Apr 20, 2011 at 17:05, Thomas Witkowski > > wrote: > > Following the mathematical representation wouldn't make it more > sense to store B but B^T, because the local matrices B_i^T are > real local and would have no o

[petsc-dev] [petsc-users] FETI-DP

2011-04-20 Thread Jed Brown
By the way, you should definitely read Klawonn and Rheinbach's "Inexact FETI-DP methods" (http://onlinelibrary.wiley.com/doi/10.1002/nme.1758/pdf , ask me if you don't have access). I think it has the most clear description of what is going on, and offers the most flexibility in terms of which spac

[petsc-dev] [petsc-users] FETI-DP

2011-04-20 Thread Jed Brown
On Wed, Apr 20, 2011 at 17:05, Thomas Witkowski < thomas.witkowski at tu-dresden.de> wrote: > Following the mathematical representation wouldn't make it more sense to > store B but B^T, because the local matrices B_i^T are real local and would > have no off-diagonal elements? > They really can't

[petsc-dev] [petsc-users] FETI-DP

2011-04-20 Thread Thomas Witkowski
Jed Brown wrote: > > I'm confuse because in the work of Klawoon/Rheinbach, it is > claimed that the following operator can be solved in a pure local way: > > F = \sum_{i=1}^{N} B^i inv(K_BB^i) trans(B^i) > > > Did they use "F" for this thing? Usually F is the FETI-DP operator > which

[petsc-dev] [petsc-users] FETI-DP

2011-04-20 Thread Jed Brown
Thomas, we should move this discussion to petsc-dev, are you subscribed to that list? On Wed, Apr 20, 2011 at 13:55, Thomas Witkowski < thomas.witkowski at tu-dresden.de> wrote: > There one small thing on the implementation details of the FETI-DP, I > cannot figure out. Maybe some of you could he