[petsc-dev] cheby.c

[Mark F. Adams]

Cheby can be tricky, textbook algorithms (eg, Saad's book) have some curve balls.  Prometheus has a Cheby implementation that I know is correct.  It was worked on by several good people and implemented in several codes and we wrote a paper on it.

Mark

On May 23, 2012, at 9:21 AM, Barry Smith wrote:

> 
> On May 22, 2012, at 4:17 PM, Hong Zhang wrote:
> 
>> Barry,
>> Do you recall the paper or detailed Chebyshev algorithm that you implemented the Chebyshev in petsc?
> 
>  No
> 
>> I added 'hybrid' to it, which is not correct. Jie is helping to fix it. Having an original
>> algorithm would help. 
> 
>   The code has also heavily evolved since first being code with bells and whistles being added. 
> 
>    Perhaps look at the templates book for the definitive algorithm :-)
> 
> 
> 
>   Barry
> 
>> 
>> On Tue, May 22, 2012 at 1:21 PM, Jie Chen <jiechen at mcs.anl.gov> wrote:
>> Then do you know who wrote the code? Hong said it was you.
>> 
>> It was written in the 90s, before version control history. 
>> Sorry, my mistake. I recall that Barry said that he wrote it when Jed was in dia... ;-(
>> Hong 
>> 
>> 
>> Hong is trying to modify the code but there is something wrong. I am helping to see what is the problem. The code itself is fine. 
>> 
>> Hard to speculate without more than "something wrong".
>> 
>> 
>> Jie
>> 
>> 
>> 
>> ----- Original Message -----
>> From: "Jed Brown" <jedbrown at mcs.anl.gov>
>> To: "Jie Chen" <jiechen at mcs.anl.gov>, "For users of the development version of PETSc" <petsc-dev at mcs.anl.gov>
>> Sent: Tuesday, May 22, 2012 1:18:07 PM
>> Subject: Re: cheby.c
>> 
>> 
>> On Tue, May 22, 2012 at 12:37 PM, Jie Chen < jiechen at mcs.anl.gov > wrote:
>> 
>> 
>> Jed, I am reading your implementation of the chebyshev code. The algorithm does not seem to be the same as the version I am familiar with. Did you implement it according to some paper or book?
>> 
>> 
>> 
>> I didn't write it.
>> 
>> 
>> What do you find strange?
>> 
>> 
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>