Optimization


DS Development&Optimization20 May 2008 06:00 pm

I continue to fail to post weekly; all the fun stuff I would want to say, I don’t think I should talk about, though.

Anyway, the Opti compo is still going along, but it’s getting close to the end – right now there are 11 days before the compo ends. I’m adding this informational post to remind people and also to alert people to a new revision of the test system, better rules for whether an entry will be accepted or not, and various other things. I’ll reiterate  the important parts on the competition page.

Firstly, the test system update: this update will probably be the final update of the test system code for this competition. Unfortunately I didn’t get all the stuff I wanted in it, I’ve been short on time and have had more than enough stress to go around :) So, this update does not contain the statistical time-sampling profiler that I wanted to add to the test app. It also doesn’t include a fractal explorer section which I had wanted to add. But on to the features that I did get around to adding: There is now a new default test set of 6 tests, they zoom in quickly on a specific point in the fractal, and are pretty complex areas to render (the number for max_iterations on the 6th image is 1400, and the horizontal and vertical steps are in units of 2^-44). I’ve included a modified example that is designed to serve as a lower bound for correctness – passing implementations should have a smaller amount of error than the lower bound. I don’t think this will be too hard, the lower bound currently exists as a modification to the multiply code that loses 3.5 bits of precision with each multiply. This actually caused less difference from the reference implementation than I had thought; currently across the 6 tests, there is a total difference of 7044 iteration counts, notably the 6 tests render a total of 147456 pixels, so this value is really barely even noticeable.

There was also a bug in the test app that caused it to only display the last test’s cycle count rather than the sum of all of them, this has also been fixed, and (in no$) the cycle count for the “lower bound” test is 0x0004CC483E1E cycles – which is 307 seconds of cputime, about 5 minutes. As the default test behavior also runs the example code alongside it, this means a test run of the lower bound takes about 10 minutes; not very good for repeated testing. I’ve added a way to start the tests without checking them, by pressing start instead of A, so the code execution time you have to sit through is purely your own fault ;) It will be pretty obvious if there are big errors, but it will still take a long time to check results against the reference function.

Ok, that’s all I have for now; I’ve been working on my own implementation just lately in assembly, but I really have no idea how well it will perform just yet. I’ll post some numbers in the comments on the Opti site once I get them.

ludumdare&Optimization05 May 2008 04:46 pm

So, the Ludumdare 11 competition is over (as of 2 weeks ago), and voting has completed (as of yesterday)- it’s been a while since I last posted.

You can see the competition results Here  - I got first place in the timelapse video, and third in the technical category – participating was a lot of fun.

Things are moving really slowly here lately, I’m trying to get a job, trying to get varioius odd projects done in the meantime… Haven’t really started on any of the big things I want to do, due to lack of time. I do hope I can get all of these things sorted out  soon.

The First Opti Competition is still moving along – in hindsight it’s really not doing as well as I’d like, and that’s mostly due to the theme. Well. I do have ideas on how to fix that – after this first compo I’ll be starting some more useful / reasonable / interesting competitions that will hopefully involve a wider array of people and won’t be quite so technically involved. I’m also going to add some more categories to the site, so there should be something for everyone.

I’m going to try to continue with weekly updates, because I know you all have nothing better to do than read about the trivialities of my life ;) yes, I’m being facetious. Sometimes I wonder why I write this at all; I do hope someone finds it interesting, but if nothing else it’ll give me something to laugh at many years down the road.

DS Development&Optimization30 Mar 2008 03:25 pm

Ok, Finally – after a lot more effort than I thought it would take – the akkit.org optimization contest (for DS) is up and running, with it’s first competition!

Although the competition technically started a day and a half ago, I haven’t posted it yet because I didn’t have the test package ready, but is ready and posted now.

So, it is with great anticipation that I submit it to you, for review: Opti’s First Competition

Anticipation like, waiting for a pie to hit me in the face, or be run over by a car, or something similar ;) I do however want to see what level of interest there is, and try to make this into something that more people will be more seriously interested in next time (I am highly curious about how many people will be interested this first time) – So, to that end I am very interested in any sort of feedback. Anyway – That’s all I want to say for now, I’ll shut up before I ramble on about it for a very long time; Thanks for looking :)

Optimization26 Mar 2008 06:16 pm

So, I was holding off on posting until I had the optimisation contest site ready – but that didn’t work very well, it’s run a lot longer than I had planned for it to (oh, only a few months longer :P), but it’s finally getting to a usable state!

Currently, all of the public-facing user interface magic is done, I’m just wrapping up a few admin pages and testing things, but it’s looking very good! I’m going to aim to finish it up and get a proper competition started this weekend. However, if you want to get started and have some time to tinker around with the site first, have fun! The site is at http://opti.akkit.org/ – there is an IRC channel set up for support and general discussion (#opti on Blitzed). Also, please note the site still contains remnants from testing, that will all be swept under the metaphorical electronic rug when I get a real contest started but for now it serves to be some data to test with and show how things work. Comments and bug reports will be most welcome, as will suggestions for improvement – a design overhaul is planned for the near future as well (well, I like the design pretty well, but it’s functional rather than elegant, and it will be better if it’s both)

DS Development&Optimization04 Dec 2007 01:33 am

Ok, so the optimization contest thing didn’t make it this last weekend :( sorry about that, I’m overly optimistic and didn’t have time to work on it enough to get it ready.

Now, I’ll take a few moments to relate some of the things that are going on in my life at the moment; as you might have noticed my online presence has been rather very thin, and my projects have been crawling along, if that – and this isn’t just for the projects that are public, even the private ones are not moving much… The culprit I’ve decided is stress, it’s the only logical cause I can come up with.

To that end, I’ve decided to quit my current job – I’ll be working for the next 2 weeks and then I’ve arranged to quit. At that point I’ll probably get some rest for a week or 2, I’m planning to visit some relatives and then I’ll devote some time to getting my currently idling projects done.

I hope I can get the optimisation contest site running in the next week or 2. January though will bring work on the nds_test_apps, probably dstunnel (due to popular demand), and some other things I haven’t figured out the order of yet. So, onwards! We will see what the future brings.