demallien

The problem with testing algorithms is that it in no way tests intelligence. I would think that 9 out of 10 programmers that know an algorithm would not be able to derive the algorithm from first principles. So you are just testing esoteric knowledge - it's qualitatively no different that asking someone questions about a specific framework / API.

You could make the argument that algorithms tend to be studied more by smarter people, but if that's what you're going for you may as well ask them about their hobbies, and hire the person that is into playing chess, or doing astronomy (or whatever intellectual pursuit you care to name).

If on the other hand you are interested in a person's ability to code, ask them to do so. The last time I had to hire someone, I wrote a small application with one module that was deliberately written in an obfuscated style. I asked candidates to bring that module under control - rewrite it in a readable code style. To do this, successful candidates needed to identify what the current code was doing by examining the public interfaces in a debugger, documenting what the calls seemed to do, prepare unit tests, and then rewrite the module in a readable style. It took about a day for most candidates to do.

At the end of that, you get to see a candidate's ability to read code, use a debugger, write unit tests, write documentation, and write well structured code, which is a pretty good coverage of the typical tasks in a developer's day. I feel this gives a much more realistic assessment of a candidate's capabilities that asking questions about a more or less randomly chosen algorithm.

Regardless, Enigma was pretty low-value intelligence. It would give you things like the daily position of u-boat packs, but generally speaking there isn't much you can do with this type of information - maybe increase the ability of your conveys to avoid U-boats, or increase slightly your ability to hunt them.

The real game was the Lorenz-stye encryptors that were used for communications between German commands. These delivered the strategic information about mid-to longterm movement of units and so on which allowed they Allies to correctly anticipate attacks. These were the messages that Colossus was used to decrypt, as opposed to the Bombes which were decrypting Enigma traffic, and which were largely derivative of earlier Polish efforts to decrypt Enigma.

I read a book a while back https://www.goodreads.com/book/show/1127838.Colossus that looks at all of this in detail. Surprisingly, if the book is correct, Turing seemed to have limited contact with the Colossus effort, and was more involved with the Enigma decryption. The Colossus people didn't seem to be terribly occupied by ideas such as Turing-completeness, they were just building machines that were capable of doing certain operations at high speed.

10ms is the absolute maximum difference in time, if the source was located on a line running through the two detectors. If the source was located on a perpendicular bisector of the line running through the two detectors, the difference in time between detections at the two detectors would be zero. Any value between the two is possible depending on the geometry.

Because Falcon9 is a big launcher taking a serious payload into orbit. This means that the first stage has to have very large engines - so large that they can't be throttled down to hover, they have to kill velocity at the point of touchdown.

It's the difference between slowing your car down gently to stop at a red light, and having your car going at max speed and slamming on the brakes as hard as you can at exactly the right moment so that you will eventually stop at the lights. One is easy to do, the other will most likely get you killed.

"The markets thought Lehman had big exposure to the US residential and commercial mortgages, hence they couldn't borrow, hence they went bust."

This is the sort of thing I mean when I say derivatives are hard to evaluate correctly. So yeah, Lehmans totally went bust because of their large amounts of trading in CDS.

If this was true, Lehman Brothers would still be in operation today. Derivatives, by their very nature, are harder to truly evaluate in terms of value, and the chance of them going horribly wrong has already been demonstrated as being non-zero (see GFC).

It's not so much the problem being simple, but more about it being a problem you have already solved. If you give me a blitter API and ask me to write a composited then yes, I can churn out the required quantity of code with ease each day. I know the problems, I know at least one solution, so I won't ever have to head up dead end alleys, stop and research options on the Internet, discover that I've chosen a really inefficient algorithm that requires a near complete rewrite to avoid, and so on. Ask me to patch an existing code base that I'm unfamiliar with to add a new option on a settings screen, and those 5 lines might take me two or more weeks to write, even though the task is simple.

I think you'll find that andreyf codes on SarcasmOS..

Firstly, you assert that everyone wants their own big car. This is not true. I don't want one, and I'm not alone in that amongst people living in cities with good public transport.

I choose my mode of travel (including cars) as a function of the time it's going to take to get there, and how much stuff I'm lugging. If I am carrying a lot or travelling out of peak hour, I take a car. If I'm under time pressure, I'll probably take the metro.

In Paris we have Autolib, which is a wonderful car service where you can reserve a car at one station and drop it off at another. There are over a thousand if these stations in the city, so there's normally one near you and your destination. But the brilliance of this is that I can go to work using public transport (because peak hour), gi to the gym after work and then drive home. Or catch public transport to a restaurant in a Saturday evening, and drive home, or whatever. Self driving cars will make this type of system even better because I can use one without having a station near me, I just call a car.

At the moment city centres get clogged by cars because public transport in the suburbs is horrible. But if you can get a car to a transport hub and then commute into the centre, I think a lot of people would prefer that to being stuck in heavy traffic for hours. Maybe not you, but many people.

Cars are still bloody expensive. Many many people make the decision not to buy a car when they live in a city with good public transport. It's only in places like Australia and most of the US where you practically need a car that ownership is ubiquitous. Elsewhere people find that there are better things to spend all of that money on...

I'm not convinced that people linking immigrants and terrorism are particularly worried about the actual immigrants turning out to be terrorists in disguise. It's more a worry that they will just add to the ghettoisation of Islamic communities, which is precisely where this latest crop of French terrorists seem to have sprung from.

Well, because the comments being made are laced with gender, so the gender of the comments is surely relevant, no? I mean, I understand where you are coming from - the title can be interpreted to apply to all men, when it only applies to some men. So adding "some" to the title might be a good adjustment. Removing "men" from the title however is not warranted.

Maybe I'm being obtuse, but wouldn't that be an argument for prohibition? As in, drugs that aren't prohibited cause much more harm than those that are?

The tube line is a custom one-off system. The components aren't though.

I'm a regular Autolib user in Paris, and I have to say Autolib is just pure awesome. It's the piece of the puzzle that has been missing in public transport, because sometimes you just need a car. Some examples:

Moving large bulky items

Getting around quickly in the suburbs, out of the city centre

Rerving parking in the city centr a ahead of time

Actually, those are the three main use cases for me. I do everything else with my electric bike or the metro. Still, the service has changed my life - I no longer own a car because of it, and I'm not alone in that. Just yesterday another friend was selling her car on Facebookfor the same reason.

Anyway, I think the Indy city council would do better by stopping worrying about who had the right to do what, and just get behind this thing. It just makes people's lives better.

Orbits are not intuitive. To head "downwards", you have to slow down your orbital velocity, which reduces the radius of the orbit. In other words you have to decelerate. When you do the maths, you actually have to decelerate more from Earth orbit to get to the sun than you do to accelerate up to solar escape velocity.

Just don't call it Rapture

All maintenance on aircraft is closely tracked. They can probably find evidence of maintenance operations that were conducted on the found piece and confirm that it matches the maintenance records for the aircraft. It's a similar idea to identifying people by dental records.

I also use Siri to send text messages if I'm driving or riding my bike, or to find the answer to a piece of trivia, or to launch applications, rather than having to hunt for them. That makes quite a lot of use cases, but nevertheless I agree with you that I wouldn't miss Siri if it was to go away

Many members of my female-only netball club use 'guys' to refer to ourselves...

Noooooo, that's the whole point! The question that is being asked is not "how to make gun owners less likely to shoot people" but rather "how to make it less likely that people get shot". Per capita is absolutely the right measure to use for the latter question.

This accurately catches the reasoning behind my approach to testing though. When you fix a bug, write a test that reproduces the bug first. That way, when someone tries to refactor the messy code, they'll know that they broke something that was causing a real big.

I generally try to have two type of test: nominal "happy case" tests that verify basic functionality of modules when used in a normal way, and bug fix tests that are labelled as such, with a reference to the bug in the bug tracking system. So now when you see my warty code and try to clean it, the test fails, and you can even find a description of the original problem that the warty code addresses. Now you know that you either have to find a cleaner solution, or just leave the warty code alone.

This system means that most of the tests I write are targeted at things that really cause bugs, not just busy-work testing of things that would never go wrong, but rigidify code bases (the more tests you have, the more you have to modify when refactoring, and how do you know if the test or the code is wrong during the refactor???)

I was just going to down vote you, that's all trolling deserves on HN, but on the off chance that you're just ignorant, and not actually trolling:

1) there are 5 OSes with more than 100million users. Apple makes two of them 2) there are 4 major web browsers out there, apple makes one of them 3) there are 3 major office suites out there, Apple makes one of them

Apple is one of the biggest software companies in the world. I suspect they are second only to Microsoft in that regard, and yes, I do include Google in that assessment.

Stick with the pricing. The application is niche, and as such should have a higher price. It has been noted many times over that software has a bimodal pricing scheme - very cheap for off the shelf software, and very expensive for bespoke software. But of course, that's the black and white view of the world. The more 'niche' your off-the-shelf software is, the closer it gets to being bespoke, and the price should rise accordingly. It works in the other direction as well of course - if you can build an application by simply tweaking an existing framework, such as building a website using Squarespace, then this should cost much less than true bespoke software.

All of which is to say that I feel that you have the right approach to software pricing. I hadn't realized this exists, but I may well become a customer in the next few days - I have been looking at options for creating UML documents in code.

One thing though, do you have a re-import feature? This is the killer feature for me - I would love to be able to create a URL diagram in your app, paste it into the top of a source file, and then copy it from the source file back into the app for modification later when the code changes. I realize that this is a tricky problem to solve, but solving it takes this from being a toy to being a true industrial tool from my perspective.

Wouldn't you just use Siri for that? I have enough apps that it's mostly too hard remembering where all but the most commonly used live, so I just tell Siri to open the app. Works like a charm.

Whilst it is true that there has only been one launch abort so far, if the Shuttle had a launch abort system it would have saved the seven astronauts aboard. Just mentioning this in case someone mistakes your post as arguing that launch abort systems are rarely useful.

I'm betting on Chuck (as in Yaeger)

That's not at all what that report says. The graph in the report is talking about the energy usage and production of one household, not global demand. Peak global demand of energy in Australia is very much in the middle of the day as offices and other workplaces run aircon / lighting / computers / industrial processes.

Paris already has a very successful shared electric car device called Autolib. I use it at least once a week, and it's brilliant. The scheme works because the battery has a range of about 150km, but the typical trip is only 5-10km. The systemight not work as well in less dense cities.

Is this news? I don't know about anyone else, but ever since my undergrad days, I see repeating patterns in nature and I just say to myself "oh, there's another partial differential equation"