[petsc-users] Typical number of iterations for CG and GMRES: Compiling knowledge base -- please contribute

[Juan Gonzalez, Ph.D.]

Friends,

 

I am trying to compile a knowledge base on what could be typical
expectations for the number of iterations  that one could see in real-life
well-conditioned CG, GMRES, and general Krylov problems.

 

I understand that the number of iterations will vary substantially depending
on problem size, matrix structure, condition numbers, quality of
preconditioners, etc. 

It would be of great value to have an idea of what to expect and under which
circumstances, driven by previous experience.

 

If you send me a quick note with your experience on number of iterations as
matrix size and other circumstances vary, I promise I will compile all the
info that I receive from the group and send a summary report to the whole
group. (please try to include problem type and the things that you notice in
your experience that affect the number of iterations the most). The main
interest is on instances that are/were useful for real life problems - for
example, please do not include studies where you extended artificially the
number of iterations to analyze the algorithm or learn things about the
convergence.

 

Thanks in advance for your contribution.

 

Best regards,

 

                Juan

 

 

Juan Gonzalez, Ph.D.

President & Chief Scientist

Accelogic LLC

13680 NW 14th St, Suite 5

Sunrise, FL 33323

Ph:      +1.954.838.1100

Fx:      +1.954.208.0018

 <http://www.accelogic.com/> www.accelogic.com

Description: Description: accelogic

 

 

"A pessimist sees the difficulty in every opportunity; an optimist sees the
opportunity in every difficulty" -

 
Sir Winston Churchill

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