Want to read Slashdot from your mobile device? Point it at m.slashdot.org and keep reading!


Forgot your password?
DEAL: For $25 - Add A Second Phone Number To Your Smartphone for life! Use promo code SLASHDOT25. Also, Slashdot's Facebook page has a chat bot now. Message it for stories and more. Check out the new SourceForge HTML5 internet speed test! ×

Comment I read a big chunk of it (Score 1) 381

Back in high school, I thought I was the most badass programmer on this planet. Could hand assemble code and hyper-optimize my programs counting clock cycles everywhere. I got into college. There was a book on algorithms in the small library the computer room had. I learned about asymptotic behavior. So I realized that my cleverly optimized O(n^2) sorting assembly program was going to eventually lose badly to a straightforward interpreted implementation of quicksort. Clearly I had to become good at this. I started reading all books I could find on the topic and very quickly I noticed that they all included a sentence meaning "If you want to understand the subtle underpinnings of this, see TAOCP." So I got a copy of volumes 1 & 3. It was expensive (I was not in USA and books were VERY expensive because of currency exchange issues). Mom & Dad chipped in and I still thank them for that. I borrowed volume 2 from a friend.

I decided to go though the book solving all exercises up to level 30. Saturday was my TAOCP day. I cannot say I read ALL of the text nor that I solved ALL problems of difficulty below 30, but I solved all that I tried and they were way more than a few. I even solve some in the 35 level, whenever I considered them interesting.

FF to the beginning my PhD studies at a good school in the USA: When taking the grad level Algorithms class, I was doing VERY well. The professor, a scary smart guy (now full professor at Stanford) asked me how may courses on algorithms and information theory I had taken. The answer was none. My undergrad degree was in Systems Engineering, from a crappy school in South America. I was never formally taught what a big-Oh was. That professor become my thesis advisor. He used to joke saying I was a walking encyclopedia of algorithms.

Will it work for everybody? Probably not. If you want to do theoretical CS, as I did, you will have to handle that math and some more anyways. CLR is more up to date and time efficient for learning. If you want to be a software engineer, chances are you are not going to be doing the heavy math, you will be using off the shelf algorithms.

Still TAOCP is a hell of a reference. Funny thing is, after finishing my PhD, I browsed through it. It looked simple, not very formal at all. I guess PhD does mean "permanently head damaged" :-)

Comment Re:My vote... (Score 5, Insightful) 316

Wiley Coyote... Super Genius.

Though, his reliance on ACME for equipment, should be reconsidered.


I always thought that Wiley Coyote depicts very well the agony of working as an engineer. The laws of nature seem to work against you. Murphy's laws are against you. The tools/equipment do not behave according to the specs, and tend to fail at the worst possible time. Good ideas fail because of implementation details or even bad luck. Yet, you cannot let the problem go, you have to fix it! One last try, ok, maybe another one!

Comment Re:I'll be first to say WTF (Score 5, Informative) 700

NP is short for Natalie Portman, and the car analogy follows:

Adleman's chief scientist, Nickolas Chelyapov, offered this illustration: Imagine that a fussy customer walks onto a million-car auto square and gives the dealer a complicated list of criteria for the car he wants.

"First," he says, "I want it to be either a Cadillac or a convertible or red." Second, "if it is a Cadillac, then it has to have four seats or a locking gas cap." Third, "If it is a convertible, it should not be a Cadillac or it should have two seats."

The customer rattles off a list of 24 such conditions, and the salesman has to find the one car in stock that meets all the requirements. (Adleman and his team chose a problem they knew had exactly one solution.) The salesman will have to run through the customer's entire list for each of the million cars in turn -- a hopeless task unless he can move and think at superhuman speed.

This serial method is the way a digital electronic computer solves such a problem.


Game Prices — a Historical Perspective 225

The Opposable Thumbs blog scrutinizes the common wisdom that video games are too expensive, or that they're more expensive than they were in the past. They found that while in some cases the sticker price has increased, it generally hasn't outpaced inflation, making 2010 a cheaper time to be a gamer than the '80s and '90s. Quoting: "... we tracked down a press release putting the suggested retail price of both Mario 64 and Pilotwings 64 at $69.99. [Hal Halpin, president of the Entertainment Consumer's Association] says that the N64 launch game pricing only tells you part of the story. 'Yes, some N64 games retailed for as high as $80, but it was also the high end of a 60 to 80 dollar range,' he told Ars. 'Retailers had more flexibility with pricing back then — though they've consistently maintained that the Suggested Retail Price was/is just a guide. Adjusted for inflation, we're generally paying less now than we have historically. But to be fair, DLC isn't factored in.' He also points out all the different ways that we can now access games: you can buy a game used, rent a game, or play certain online games for free. There are multiple ways to sell your old console games, and the competition in the market causes prices to fall quickly."

Terry Pratchett's Self-Made Meteorite Sword 188

jamie writes "Fantasy author Sir Terry Pratchett says he was so excited after being knighted by the Queen that he decided to make his own sword to equip himself for his new status... the author dug up 81kg of ore and smelted it in the grounds of his house, using a makeshift kiln built from clay and hay and fueled with damp sheep manure."

Comment Re:Yeah, maybe (Score 1) 612

What if you are depending on a library written by someone not as fscking brilliant as yourself? If that library has a bug and throws an exception you will have to deal with it. You may even have to propagate the exception up to be handled by someone else. That may require some cleanup.

Besides, bugs are not the only conditions to trigger exceptions. Unusual but possible events can do it as well. Out of disk or memory conditions are such examples. Some idiot/rogue user may delete a needed file from the command line and so forth.


Decades-Old Soviet Reflector Spotted On the Moon 147

cremeglace writes "No one had seen a laser reflector that Soviet scientists had left on the moon almost 40 years ago, despite years of searching. Turns out searchers had been looking kilometers in the wrong direction. On 22 April, a team of physicists finally saw an incredibly faint flash from the reflector, which was ferried across the lunar surface by the Lunokhod 1 rover. The find comes thanks to NASA's Lunar Reconnaissance Orbiter, which last month imaged a large area where the rover was reported to have been left. Then the researchers, led by Tom Murphy of the University of California, San Diego, could search one football-field-size area at a time until they got a reflection."

Ubuntu LTS Experiences X.org Memory Leak 320

MonsterTrimble writes "Ubuntu 10.04 LTS Beta 2 is experiencing a major memory leak due to patches for X.org. 'An X.Org Server update that was pushed into the Lucid repository last week has resulted in the system being slower and slower as it is left on, until it reaches a point where the system is no longer usable. ... In order to make the Ubuntu 10.04 LTS deadline, the developers are looking at just reverting three of the patches, which brings the GLX version back to 1.2. Ubuntu developers are now desperate for people willing to test out this updated X.Org Server package so they can determine by this Friday whether to ship it with Ubuntu 10.04 LTS or doing an early SRU (Stable Release Update). Right now this X.Org Server that's being tested is living in the ubuntu-x-swat PPA.'"

Brain Training Games Don't Train Your Brain 151

Stoobalou writes with this excerpt from Thinq.co.uk: "A new study has shown that brain training games do little to exercise the grey matter. Millions of people who have been prodding away at their Nintendo DS portable consoles, smug in the knowledge that they are giving their brains a proper work-out, might have to rethink how they are going to stop the contents of their skulls turning into mush."

PhD Candidate Talks About the Physics of Space Battles 361

darthvader100 writes "Gizmodo has run an article with some predictions on what future space battles will be like. The author brings up several theories on propulsion (and orbits), weapons (explosives, kinetic and laser), and design. Sounds like the ideal shape for spaceships will be spherical, like the one in the Hitchhiker's Guide movie."

Jetman Attempts Intercontinental Flight 140

Last year we ran the story of Yves Rossy and his DIY jetwings. Yves spent $190,000 and countless hours building a set of jet-powered wings which he used to cross the English Channel. Rossy's next goal is to cross the Strait of Gibraltar, from Tangier in Morocco and Tarifa on the southwestern tip of Spain. From the article: "Using a four-cylinder jet pack and carbon fibre wings spanning over 8ft, he will jump out of a plane at 6,500 ft and cruise at 130 mph until he reaches the Spanish coast, when he will parachute to earth." Update 18:57 GMT: mytrip writes: "Yves Rossy took off from Tangiers but five minutes into an expected 15-minute flight he was obliged to ditch into the wind-swept waters."
PlayStation (Games)

US Air Force Buying Another 2,200 PS3s 144

bleedingpegasus sends word that the US Air Force will be grabbing up 2,200 new PlayStation 3 consoles for research into supercomputing. They already have a cluster made from 336 of the old-style (non-Slim) consoles, which they've used for a variety of purposes, including "processing multiple radar images into higher resolution composite images (known as synthetic aperture radar image formation), high-def video processing, and 'neuromorphic computing.'" According to the Justification Review Document (DOC), "Once the hardware configuration is implemented, software code will be developed in-house for cluster implementation utilizing a Linux-based operating software."

Comment Re:Well $27B buys you a lot of panels... (Score 2, Interesting) 416

I'm going to review your physics.

If you installation produced 45 KWH of ENERGY during a 5 hour period (being conservative here), it's average output POWER was 9KW. Let's say 10KW to simplify the math.
Now, you will need 11000 times as many panels to reach 110MW. The total number of panels per mile you need is 48*11000/116=4551. That is one panel every 14 inches (if i got the units right, not used to imperial).

Feasible? I would say it still is, but not as much as your calculations suggested

Slashdot Top Deals

You cannot have a science without measurement. -- R. W. Hamming