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Comment Dome sweet dome (Score 1) 274

Just get your city councilors to dome your city. If you get a double-glazed dome then your house doesn't have to keep in heat, or keep out rain, or not fall over in a strong breeze; so you could easily build the walls from paper (recycled of course) and the frame out of cardboard. Domed cities don't just mean cheaper housing : you never to carry an umbrella, you don't have increased car accidents when it rains.

Comment Re:The blame game (Score 1) 220

but in a general sense unless the actual source of the problem, a complete lack of laws protecting our privacy, is brought to light, I do not expect any real change.

I'm pretty sure there a plenty of laws protecting real privacy. Facebook users seem to have a different definition : not about protecting their personal individual information but protecting their clique's information. Protecting cliquishness is probably a bad thing. You'll eventually have a nation sized clique gossiping (in facebook defined privacy) about how awful neighbouring nations are.

Comment Re:NASA tested this a while back (Score 1) 673

What that story really implies is that there was an ash cloud from an icelandic volcano over europe in February 2000. No air space was shutdown. And noone crashed (including the Nasa plane). They found some "scary" engine damage by examining their engine with a microscope.

(By the way, your link is dead, here is the google cache)

Comment Re:Interesting (Score 1) 984

those who know how big a MB actually is will continue knowing, and will quickly (and eagerly) find the ways to make their computers show sizes correclty.

How big is a megabyte?

Does any binary-ist really know without reaching for their calculator? I date back to 1980's microcomputers and could recite all the powers of 2 upto 2 to the 16th (65536). I gave up after memory sizes went beyond that. I hand assembled Z80 machine code by looking up their hex codes in an opcode table. We don't live in the world where we deal directly with binary any more.

I've been a decimal-ist for a few years and early on I actually almost finished a decimal file manager (there weren't any at all back then). It used resistor notation (where k/M/G isnt at the end of the number, but in the middle replacing the decimal point [period]). It showed all the digits in the filesize, but only the first four were in black, the rest were ghosted down to gray. That way you could easily read the approximate size, or look harder and read the complete number. Eg 314159265 would appear as 314M159265

User Journal

Journal Journal: light

Today I changed a light bulb.

Comment Re:Might be a mistake but not where Rob is pointin (Score 1) 436

Well unless there is something else going on Rob needs to go back to school too. A simple quicksort algorithm with the comparator replaced with a random choice becomes a recursive random partition of the array. A simple inductive argument shows that this will not produce the unbalanced results he found. So the problem is elsewhere (most likely in the RNG seeding or a bias in the pivot selection, if he is running it in a tight loop and the seed is something like, current second, then the same seed may appear several times).

You do realise that quicksort is whole family of algorithms? Most library routine writers consider it a bug if you sort the same data twice and it comes up in a different order, so they tend to avoid random pivot and use median of 3 or 9 pivot instead. These will give biased shuffling. They also also switch to insertion sort for small subarrays which will lead to biased shuffling.

Closing the walls partitioning takes 1/2 to 1/3 times as many swaps as the Lomuto partitioning (which is a simple left to right for loop) so it's usually the preferred method to partition. Lomuto also goes quadratic for equal valued elements. Most closing the walls partitions use the pivot as a sentinal, but with a random comparison the indexes can walk right past the end the subarray and generate an array index error.

Comment Re:Frankly, I was disappointed (Score 1) 544

Red matter isn't that big a stretch from today's science. Strange Matter has fairly strong theory behind it and red is just another type of quark.

Besides I vaguely remember all the star trek episodes and definitely vaguely remember a series finale where Captain Bristow has to stop a big red matter ball from turning a whole city into zombies.

Comment Re:Keep it simple! (Score 1) 956

Actually it (thanks to 2s complement arithmetic) gives the right answer. "A" decrements down to MIN_INT then wraps round to MAX_INT then decrements all the way down to 0. It effectively calculates the unsigned equivalent of "a" (being 2**32 -a) times "b". The result of that is b*2**32 - b*a. The first part doesn't fit in your int, so you're left with -b*a. Of course, if you have 64-bit ints you may have wait a few decades.

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