[Developers] inv problems.

[Arni Magnusson]

Hi Dave,

I notice that I'm the only recipient of this important question. I 
appreciate your faith in me, but efficient linear algebra with AD objects 
is really outside my area of expertise.

I haven't looked at the inverse or solve code (old, new, or proposed), but 
posted the GCC profile diagnostics to help the development team to improve 
the performance of the 'vol' example, which became 3 times slower between 
9.1 and 10.0. The profile diagnostics point at some culprit functions, and 
Derek Seiple told me (25 Apr email) that he is currently following those 
leads.

This is definitely a high-priority issue. Given the nature of the problem 
(we have 9.1 code that works fast) and the upcoming developer workshop, 
I'm optimistic it will be solved in version 10.2 or 11.0.

Cheers,

Arni



On Thu, 19 May 2011, dave fournier wrote:

> Hi,
>
> I'm a bit woried about these problmes with inv and maybe solve taking so 
> long.
>
> It kind of breaks the entire software. That is what I alway expected to 
> happen eventually.  The idea is that it is supposed to be fast. I 
> produced a sketch of the code proper working code but it seems to have 
> been screwed up. Any thoughts?
>
> Dave
>