CFD Online Discussion Forums

CFD Online Discussion Forums (
-   Main CFD Forum (
-   -   Tridiagonal System (

Zhong Lei May 21, 2001 03:47

Tridiagonal System
Hi, I wanna if there is any method to efficiently solve a 1-d tridiagonal linear system quation on a vector machine. Any idea?

Thanks in advance.

Ray-zoo May 22, 2001 21:04

Re: Tridiagonal System
Solution from tridiagonal linear equations could be computed with Thoma's algorithm, wich is "pivot de Gauss" method for this particular case.

Do you really need a vector machine for this ?

Please, ask for the algorithm.

Best regards,


Zhong Lei May 22, 2001 23:04

Re: Tridiagonal System
The vector rate of Thoma's algorithm is too low when it runs on a parallel machine. I want to improve the vectorization. of the following do-loop.

<DD> do I=1,IMAX <DD> D(I) = D(I) -W(I)*D(I-1) <DD> enddo </DD>

Thanks Zhong Lei

Ray-zoo May 24, 2001 14:18

Re: Tridiagonal System
Dear Zhong Lei,

Apologises for this late answer due to sparse internet connection.

After a read of J.C. Chien's post about vector machines, I could not guess how to vectorize a loop which requires previous iteration step result.

As I am mostly newbie to this forum, I can not confirm own opinion that meaningless requests may be a reason for none, or very few answers.

If you need running some parallel machines, couldn't you run some domain decomposition method (ddm) ?

I had an internet link to those methods, but could not find it before this post.

Maybe someone else here knows where to find informations about ddm(s).



All times are GMT -4. The time now is 07:49.