PCG code in MATLAB

Hi! I am a PhD student, and I am testing a new iterative solver
against the standard conjugate gradient (CG) algorithm. Does anyone
know the specific preconditioned CG (PCG) code MATLAB uses? What
kinds of "tricks" does it use to speed convergence? (I have written
a separate code to do CG, but my implementation of CG takes many more
iterations than MATLAB's PCG code, even without preconditioners.)
Thanks for your help!

"Jerry O'Neal" <joneal@isye.gatech.edu> wrote in message
news:ef0762f.-1@webx.raydaftYaTP...
> Hi! I am a PhD student, and I am testing a new iterative solver
> against the standard conjugate gradient (CG) algorithm. Does anyone
> know the specific preconditioned CG (PCG) code MATLAB uses? What
> kinds of "tricks" does it use to speed convergence? (I have written
> a separate code to do CG, but my implementation of CG takes many more
> iterations than MATLAB's PCG code, even without preconditioners.)
> Thanks for your help!

In the MATLAB Command Window, type either "doc pcg" (without the quotes) for
a reference to a book from SIAM or "edit pcg" for the code used by the PCG
function.

--
Steve Lord
slord@mathworks.com

Steve,

Thank you for the info. I will take a good look at the code and
compare it to mine. Appreciate your help!

Jerry

Steven Lord wrote:
>
>
>
> "Jerry O'Neal" <joneal@isye.gatech.edu> wrote in message
> news:ef0762f.-1@webx.raydaftYaTP... 
> anyone 
What 
> written 
many
> more 
preconditioners.) 
>
> In the MATLAB Command Window, type either "doc pcg" (without the
> quotes) for
> a reference to a book from SIAM or "edit pcg" for the code used by
> the PCG
> function.
>
> --
> Steve Lord
> slord@mathworks.com
>
>
>