KTechlab

I vote IRC ( channel #ktechlab-devel ) ?

By the way, sorry for the off-topic, but I think this could be a good
idea to have an IRC channel for support / development ( #ktechlab &
#ktechlab-devel? or just one of those?)

Richard

On Wed, Feb 18, 2009 at 11:28 AM, Julian Bäume <julian@...> wrote:
> hi,
> just to have it in a separate thread:
>
> Some questions from me: where/how should we do the meeting? jabber-group-chat?
> irc?
>
> I setup a wiki page to plan this event:
> http://www.ktechlab.org/wiki/index.php?title=Devel:Meeting-0902
>
> Discussion can be done on the mailing-list.
>
> bye
> julian
>
> PS: looking forward to this meeting, since IMHO this could be quite
> productive.
>
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On Wednesday 18 February 2009 13:26:15 Richard Rondu wrote:
> I vote IRC ( channel #ktechlab-devel ) ?
>
> By the way, sorry for the off-topic, but I think this could be a good
> idea to have an IRC channel for support / development ( #ktechlab &
> #ktechlab-devel? or just one of those?)
Well, besides the meeting, I just registered #ktechlab on freenode network. I 
choose it, because irc.kde.org links to freenode and therefore every kde-
project is located there.

We could of course do the meeting there, but it's ok for me to meet somewhere 
else. I didn't join #ktechlab-devel for now, because I don't see the point, 
yet. We can open #ktechlab-devel if it's needed, IMHO #ktechlab should for now 
be enough.

bye then
julian

On Wed, 18 Feb 2009 13:26:15 +0100, Richard Rondu  
<rondu.richard@...> wrote:

> I vote IRC ( channel #ktechlab-devel ) ?

  That won't work for me. (The same story again: I'm behind a firewall, and  
some (read:most) ports are blocked by it).

  Jabber seems to work (with my gmail account; haven't tested it more  
seriously). Other suggestions are welcome.

  And yes, I'm in GMT +2 time zone.

  Zoltan

On Wednesday 18 February 2009 03:45:56 Alan Grimes wrote:
> Take my advice, don't get started on profiling and optimization unless
> you have several days worth of time to waste. =P
>
> The biggest CPU sucker in ktechlab is the linear algebra engine. The
> reason it gets called so much is that non-linear things such as
> transistors need to iterate in order to converge on their instantaneous
> DC conditions... I found several ways to reduce the number of times
> QMatrix[] is called... GCC doesn't seem to be inlining it, that could
> also be a fairly substantial boost. The biggest gain was to convert a
> copy (double) loop into a memcpy, that was a very substantial gain!
>
> The most obvious way to get even more out of it is to convert to use
> liboil... =P
What about using eigen2? The developers just released an interesting interview 
on the dot.
http://dot.kde.org/2009/02/16/interview-eigen-developers-20-release

Since it is in kdesupport, we don't need any external dependencies here. (We 
technically don't even link against any shared library, since eigen2 are just 
header files.)

> I fixed a few memory leaks too but a substantial number of trivial leaks
> remain, (I added comments in the code to point them out...)
>
>
> I would like to set up a design meeting sometime next week where people
> can argue over what direction the KDE4 port should go... (even though
> kde4 looks like the biggest regression in open source history...)
+1 from me. We just need to get our time-zones in sync ;)
I am GMT+1, Zoltan is GMT+2, I think.

bye then
julian

On Wed, 18 Feb 2009 03:45:56 +0100, Alan Grimes <agrimes@...>  
wrote:

> Take my advice, don't get started on profiling and optimization unless
> you have several days worth of time to waste. =P

  But don't forget:

  "The First Rule of Program Optimization: Don't do it. The Second Rule of  
Program Optimization (for experts only!): Don't do it yet.” - Michael A.  
Jackson" (  
http://en.wikipedia.org/wiki/Optimization_(computer_science)#Quotes )

  In my opinion the most important quality of the code is to be easily (1)  
maintainable, (2) reliable and (3) fast. So don't optimize if (1) and (2)  
are not fulfilled.


>
> The biggest CPU sucker in ktechlab is the linear algebra engine. The
> reason it gets called so much is that non-linear things such as
> transistors need to iterate in order to converge on their instantaneous
> DC conditions... I found several ways to reduce the number of times
> QMatrix[] is called...

  What about allowing to user to tune / relax convergence error conditions.  
Precision vs CPU time balance? :)

> GCC doesn't seem to be inlining it, that could
> also be a fairly substantial boost. The biggest gain was to convert a
> copy (double) loop into a memcpy, that was a very substantial gain!

  For debug builds, I'd have let there that loops. But still.. was that  
copy operation needed at all? :P

On Tue, 17 Feb 2009 22:17:24 +0100, Lawrence Shafer <detroit371@...>  
wrote:

>
> I just Checked out revision 204, and still have the same problem, just  
> not as
> bad. Am I getting it from the wrong place?

  Try (any) branch after rev. 208.