[petsc-dev] the complex dot business

Matthew Knepley knepley at gmail.com
Mon Feb 27 11:01:49 CST 2012


On Mon, Feb 27, 2012 at 10:55 AM, Barry Smith <bsmith at mcs.anl.gov> wrote:

>
>   I'm afraid the sudden appearance of the blas dot for complex numbers
> problem is my fault.
>
>   Traditionally since 199x we never used the complex dot product from blas
> because of the return complex type problem. VecDot_Seq() used #ifdef for
> complex and a simple loop.
>
>   Since some blas norm suck I off-hand told Shri to use dot for norm and
> wasn't thinking the complex case.
>
>   Since then, of course, the complex dot problem has been coming up.
>
>   Maybe it is best to continue to never use complex blas dot and just
> change the VecNorm_ routines to use norm for complex and not dot.? Just
> throw away this silly problem and time sink?


Why is this such a problem? Just use PetscScalar for the BLASdot_() return
type and its fine.

   Matt


>
>    Barry
>
>


-- 
What most experimenters take for granted before they begin their
experiments is infinitely more interesting than any results to which their
experiments lead.
-- Norbert Wiener
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20120227/7a4cc2a5/attachment.html>


More information about the petsc-dev mailing list