Dear members, I had to implement the projection preconditioner (P = I - A*R*(A_H)^1 *P) along with an standard preconditioner (M). And I read in some thread of users list that multilevel preconditioner can better handled by PCMG too, thus I had tried to implement the later (M) as pre smoother, where as the earlier (P) as CGC in PCMG framework. 1. Does it make sense ? or the coarse grid correction of PCMG only does this part: R*(A_H)^1 *P ?? 2. How can I adapt my projection preconditioner (P) as (P1 = I - A*R*(A_H)^1 *P + R*(A_H)^1 *P ) ? I hope made you to get my problem. Even sorry for not a good narration. Thank you in anticipation, Abdul H. TechnischeUniversiteit Delft Faculteit Elektrotechniek, Wiskunde en Informatica Numerical Analysis
On Tue, Mar 6, 2012 at 08:50, Abdul Hanan Sheikh <[email protected]>wrote:
I had to implement the projection preconditioner (P = I - A*R*(A_H)^1 *P) along with an standard preconditioner (M). And I read in some thread of users list that multilevel preconditioner can better handled by PCMG too, thus I had tried to implement the later (M) as pre smoother, where as the earlier (P) as CGC in PCMG framework.
1. Does it make sense ? or the coarse grid correction of PCMG only does this part: R*(A_H)^1 *P ?? 2. How can I adapt my projection preconditioner (P) as (P1 = I - A*R*(A_H)^1 *P + R*(A_H)^1 *P ) ?
It's still not clear exactly what you want the method to do. PCMG can do additive or multiplicative cycles. For more general composition, see http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/PC/PCCOMPOSITE.h... http://www.mcs.anl.gov/petsc/petsc-current/docs/manualpages/PC/PCGALERKIN.ht... I see the man pages are lacking details, the user's manual has more details.
participants (2)
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Abdul Hanan Sheikh -
Jed Brown