Archive for December, 2008

Bayesian arguments about climate sensitivity

… seem unconvincing to me. I’m just not convinced by the reasoning behind the choice of prior. Which isn’t to say I’ve thought about it enough for a coherent critique to emerge, otherwise you would be reading it. The argument just doesn’t compell me. What I’d like to see to find this stuff more compelling is perhaps an iterative process where the effect of each new study/piece of evidence is shown.

Seems to be there is a tendency to go from ‘we should use Bayesian probability for decision making’ to ‘we should use Bayes theorem for all our beliefs’. Which is quite a big philosophical jump. I’m still rather partial to the Popperian view that a belief is rational provided it has not been discredited, and you are open to (indeed, seek) evidence to its contrary.

Like many other dynamical modellers I’m suspicious of statistical models. The underlying premise of statistical models is that the future will be like the past, which reeks of all swans are white style inductive fallacy. I’m using Bayes theorem in some ideas I’m pursuing at the moment, and trying to be quite open to it, but there’s something about it I find a little uncomfortable. Maybe when I get around to reading Jaynes properly I’ll be converted. The idea that all rational agents must believe the same things I find disturbing, and perhaps a bit dangerous.

Not going to link to any of Annan’s stuff from here as it is mostly drafts (look up his website if you are interested), and this critique is hardly coherent. I just needed to get my reservations down on paper.


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More on posthuman WoW

With reference to the Yudkowsky series on ‘fun theory’, which is quite an enjoyable read, and topical since I’ve been reading a lot of Iain M. Banks.

Unlike (commentator whose argument was more or less that games are a waste of time) who is obviously a puritan, I rather enjoy the occasional spot of idleness. For a non-trivial number of people, playing WoW for a couple of hours a day is more fun that playing real life. Rather than make thinly veiled moral judgements about folks for their unproductivity, perhaps he should consider what makes certain games so engaging.

I spent a year playing a lot of WoW, attaining non-trivial sucess in both raiding and competitive PVP, but I gave it away, partly because the time commitment became too great and partly because what passed for progression started to lose its shine.

So, being suitably qualified, I’ll take a stab at a few features that make this virtual social experience psychologically rewarding:

1. Competition with minimised risk. I love fighting. Seriously – nothing beats the adrenaline buzz, time compression and sheer physicality. Unfortunately even controlled fighting in the physical world entails a level of risk that as a father I’m not willing to assume. Simulated violence, while a poor substitute, helps to fill the void.

2. Persistent progress. Sure online FPS is fun, but when you log on you’re always the same guy (more or less). There’s also less risk of losing your shirt in an MMO compared to real life.

3. Social challenges. Much of the game content consists of elaborate logistical and combinatorial problems that require research, problem solving, and team coordination. All of which are fun.

I see a future where billions of uploaded humans exist primarily in a cartoonish sim, working out how to beat the latest uber boss the AI has dreamed up in order to get phat lewt.

An amusing response, reproduced here without permission of any kind:

@ ac: I agree with everything you said except the part about farming a scripted boss for phat lewt in the future. One would think that in the future they could code something more engaging. Have you seen LOTR… PK

And another chunk of discussion:
“The universe has a set of unchanging rules, a game is perpetually balanced by series of patches and crutches in unpredictable places. By being creative you are fighting against game developers, which is pointless because they will actively oppose and get rid of you through their control over the sandbox.”

Yeah, part of what the patch cycle achieves is to bring the world back to equilibrium. I’m not sure it’s as strong as game developers not wanting people to innovate, it’s more that the art of building engaging yet constrained virtual worlds is still in its infancy. Keeping a closed rule set (disallowing innovations like bot writing, scripting new actions etc) makes the problem more manageable.

Patches add new fun, and invariably introduce new imbalances and potential exploits – just when you figured out how to optimize for the old ruleset, along comes the patch and you need to rerun the numbers, do some research, run a few experiments, and possibly change the way you do things.

I don’t think the stereotype of gamers as unfit junk food eating slobs with no girlfriends or ‘real’ hobbies is useful. Assuming adequate nutrition, exercise and social activity (and why wouldn’t you), gaming has roughly the same ‘real world benefit’ as opera, growing roses, reading Iain M. Banks, hiking, photography, watching football or masturbating.

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PIL to add colorbars to images

Problem: you have a set of plots, a single image with the color bar for these plots and you want to add the colorbar to each plot, not manually.
Solution: Python Image Library. Making no representations that this represents a particularly elegant or efficient way to do this, here is my solution:

from PIL import Image
import glob
imout ="RGB",(566,385),(255,255,255))
cim ="legend.png")
for infile in glob.glob("*plot*.png"):
im =
cbar = cim.crop((0,0,127,517))
cbar = cbar.resize((76,385))
plot = im.crop( (0,0,im.size[0],im.size[1]) )
sz = imout.size
pcoords = ( (sz[0]-76),(sz[1]-385),sz[0],sz[1] )
print pcoords
print cbar.size
imout.paste(cbar, pcoords)
imout.paste(plot, (0,0,490,385)),"PNG")

You’ll notice I’ve somewhat lazily hard-coded the dimensions of the colorbar and the plots. legend.png refers to the colorbar, and the glob is used to get a list of all the plots.

Not sure how to get wordpress’ code tag to respect my indentation, but you know what you need to do to make the code work.

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Bioshock – a sucessor to Deus Ex

I never played the original System Shocks 1 and 2. By the time I heard how awesome they were, Windows 98 was a distant memory and that was that. I did, however, spend many an hour working and reading through the massive interactive literary masterpiece that was the original Deus Ex. If I sound gushing, it’s because I really do think Deus Ex remains the best game yet made in its genre. I have yet to come across.

So discovering Bioshock has been a real pleasure, because it contains that same sense of story discovery, and a similar level of rich references to literature and philosophy. It does not contain as much volume of content, the themes are not as mature as Deus Ex, and ethical choices are fewer (really there is only one). Where Deus Ex was a response to singularitarian philosophy (if I can lump Drexler, Kurzweil and others into this category), Bioshock seems to be very much exclusively about Ayn Rand’s ideas. “Who is Atlas?” says it all, really. I’m only halfway through, so please no spoilers.

It’s been a long time, and I suspect it will be another long wait before a similar masterpiece makes it through the games industry filter.

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