HN user
https://github.com/mmaldacker/Vortex2D
It should work on macOS/iOS via MoltenVK, but I haven't tested it extensively.
It's a hybrid simulation with particles for the advection and a grid to ensure incompressibility.
1. The "reverse-complement" problem here is simply about reading a file, reversing strings and mapping a small set of characters to another one and printing the result. This is really a simple problem and there aren't a lot of optimisations to be done. Really this about having the fastest I/O library and thus doesn't seem like a good way to compare C and Haskell. If you look at the various solutions presented on benchmark games, the core algorithms are all the same and they only differ on how to read/write and the use of threads.
2. The author talks about the importance of reducing cache misses due to pointer indirection and then proceeds by implementing a character buffer as a linked list of small buffers...
3. The C version reads and writes character one by one, this can be greatly improved by reading/writing bigger chunks at once. Actually, the author points out this optimisation but says "that would require significant changes to the code;". So the author spent time optimising the Haskell version, but spending time optimising the C version is too much work? And then arrives at the conclusion Haskell is faster?
4. Commenters on the author's blog cannot reproduce the results...
This falls in the very specialized fields, but traders/brokers certainly need to be good at mental calculations.
the Netherlands has fewer than 17 million residents and a language that nobody else speaks
If you don't count the flemish in Belgium (about 6-7 million people). In addition, (almost) everybody speaks english.
One of the hardships Dutch startups face, says Kroes, is overcoming the natural Dutch tendency to be humble.
Really? This is not the impression I get from the Dutch. Belgians love to make fun of Dutch people for being arrogant. There is also a very strong culture of entrepreneurship in the Netherlands, starting and having a successful company is highly regarded. And there are already a few successful startups, like ticketswap which recently opened in several other countries.
Technological advancements are made. UDP Broadcast was completely broken in the 90s in Linux and was fixed by people in the finance industry. High speed network cards are constantly improving thanks to those same people.
dictionary is not necessary, the C++ impl just counts the number of words. This can be written as:
int word_count(const char *const filename)
{
std::ifstream file{filename};
return std::distance(std::istream_iterator<std::string>{file}, {});
}Upgrading and maintaining a transport infrastructure is necessary for big cities regardless of the wall circumstances. You don't think London, Paris and other big metropolitan cities in Europe spend billions on upgrading and maintaining their public transport infrastructure? I don't see Berlin having a completely automated metro like the DLR in London, or NFC cards like pretty much any other metro in Europe.
Back in the 70s, you could rock up at the airport twenty minutes before your flight left
This still exists, for example Tegel airport in Berlin. Also, in the 70s there was waaaaaay less traffic in airports so it is simply not a fair comparison.
Sadly, I bet the way we'll end up equalizing this will be that somebody will eventually bomb a TGV and we'll have to start doing the two hour confiscate-your-kids'-apple-juice routine at the train station too.
and also remember Berlin's system is essentially new and was rebuilt after reunification so you are looking at a modern system.
After the reunification, they only had to reconnect the lines that were separated by the wall. Only a few places needed some extensive work. You probably meant WW2 where most lines were destroyed. Note that Berlin was also one of the first cities in the world to have a metro system.
No one is keeping you from remaining in Germany, are they? I can guarantee you they will approve your work permit and you can become a resident and eventual citizen.
The horror!
Berlin had a maglev metro for a short while back in 1989: http://en.wikipedia.org/wiki/M-Bahn
The barcelona chair is a classic furniture from the bauhaus period designed in 1929, which is not even close to the "midcentury" period defined in the article.
While implicit operator overload was probably a C++ mistake
are you talking about the implicit conversion operator or operator overloading in C++?
For the former, it has been vastly improved in C++11 with the addition of explicit conversion operator. For the later, some very important capabilities of C++ rely on operator overloading namely the assignment operator (copy/move assignment) and the function operator (allows what C++ calls functors). Another useful thing with operator overloading is allowing the creation of generic functions that work on existing types (int, float, ..) and user defined types, for example std::accumulate.
If you want to read up more on this, look up third culture kids. The wikipedia page is a good start.
Not a single data point in this theory. The reason you sometimes wake up just before the alarm (at least I wake up before my alarm because I actually check the time) is because of conditioning. Our biological clock is pretty accurate. An example of that, in university I could easily sleep on the week ends till noon. Now that i've been working for many years and waking up regularly at the same time during the week, I wake up naturally around the same time during the week end (unless I went out late the day before of course).
It's a low pass filter. And I'm assuming the low-pass is used in the DAC to cut off high frequencies it cannot handle.
or just calculate the eigenvalues & eigenvectors of Q.
In this case, it makes no difference. The array is used instead of a struct to save a few lines of code and making the title of this post more impressive.
It's worth a lot. M&A or quarterly results can move stock prices quite significantly and knowing about those before they are public will allow you to bet against it on the market.
They do deprecate things, e.g. exception specification and the auto keywords was re-purposed.
copying the data was probably the bottleneck, not malloc.
Calculating greeks is not very difficult and bandwidth is going to be the bottleneck due to the high number of inputs necessary to calculate them. So no wonder that CPUs outperforms GPUs. Also, real time calculation of greeks is very easily achievable for the simple products (e.g. listed derivatives), banks are struggling to get real time performance for their more complex OTC products.
Apple doesn't even tell you how much RAM their phone have. Or what the CPU/GPU frequencies are.
Legal problems and technical problems aside, what are you going to gain by intercepting the traffic? Most of the traffic is going to be market data and order data which are public information (well, order data is public once it hits the exchange). You can take advantage of knowing about order data before it hits the exchange but then you'd have to transmit that information extremely fast, which using a drone (and against those huge radio tower) is going to be pretty much impossible.
Front running is something else, http://en.wikipedia.org/wiki/Front_running
The "nascent payment system" which is Apple Pay is better supported by the credit card companies than Google Wallet. It only remains to be seen how many retailers will switch to NFC.
Regulations in the state requires every POS to support the EMV technology by October 2015. From what I've seen, most retailers will have to upgrade and the new machines pretty much all include NFC technology. So by the end of next year, NFC should be available with almost every retailers. I don't think it's a coincidence that Apple is releasing NFC now (they could have easily done it with the iPhone 5 or 5S)
And the article doesn't even mention Fibonacci or Al-Kashi.
C++ is 35 years old and predates Haskell and many other "modern" languages like Java, C#, Python, ... So yes, compared to what C++ was originally, it has become modern.
Berlin has a debt of over 60 billion euros, with an annual budget of 20 billion, 5.5 of which comes from the other laenders. This is huge, the other laenders have complained multiple times that they need to cut costs. Its GDP is 80 billion, compared to frankfurt (70 billion) or munich (60 billion) it's nothing as its a much bigger city. Berlin doesn't have a financial sector or any major industry really. Population has stayed (more or less) the same for the last 60 years.
Yes Berlin looks amazing considering ww2 & cold war, but is nowhere near the major european capital it should be.
Also, London today from London 2 decades ago is very different, a simple example is canary wharf that didn't have a single sky scraper 23 years ago.
People have been expecting Berlin to have huge growth economically, in population, real estate value, etc since the fall of the wall. This has not happened yet (at least, not at the rate that was expected). I doubt it will happen with startups.
Your second solution already exists and is called an auction. Most exchange have an auction before market open and one after market close. Some even have auctions during the day.