Follow Slashdot blog updates by subscribing to our blog RSS feed

 



Forgot your password?
typodupeerror

Comment: Re:GPL is necessary and sufficient. (Score 3, Interesting) 64

by Phillip2 (#49374283) Attached to: India Mandates Use of Open Source Software In Government

"How many times has this happened"

MySQL is the obvious example, I think. It can happen with GPL, but it can only happen with the agreement of all the copyright holders, which is, in practice, unlikely. So, for instance, the linux kernel is unlikely to ever be released under any license other than GPL because there are so many copyright holders. Projects with a single copyright holder, usually through a copyright assignment policy could be relicensed.

Comment: Re:Devo said it best (Score 2) 385

by Phillip2 (#49290195) Attached to: Ask Slashdot: Choosing a Laptop To Support Physics Research?

The disadvantage with a Mac is if any of the hardware breaks you are stuffed. Macshop replacements are slow, expensive and inflexible.

The second problem I know many bioinformaticians (which is what I do) have, is that most of the scientific software is in one of the numerous non-mac packaging systems. And of different ones. So you end up with three copies of basic tools like python.

Comment: Re:Meanwhile... (Score 2) 283

It's a good point, but then the CO2 emissions have consistently gone up for years, so even if there is a margin for error and they get close enough to be within the margin for error, then it's interesting.

Of course, it could also be just total nonsense, and the result of some strange statistical blip. Another possibility, is that it's the measurement of economics which is wrong -- after this is "the first time out of a recession" not "the first time". When I look at economics, I still get pretty depressed, so perhaps that it is the broken measurement.

Comment: Re:Why Force Your Children to Live in the Past? (Score 1) 734

by Phillip2 (#49194925) Attached to: Ask Slashdot: Should I Let My Kids Become American Citizens?

Unfortunately you do become eligible for US taxes. As the OP says, capital gains for example on the sale of a first house. This is not taxable in many EU countries, but is taxable in the US. So, you have to give that cash to the US government when you sell a house because the US has a tax that the EU does not. Of course, if there is a European tax that the US does not have, you have to pay that as well.

Like all things to do with immigration, it's pretty unclear what the best option is here. No wonder the OP is confused.

Comment: Re: A giant lagoon dam (Score 1) 197

by Phillip2 (#49167665) Attached to: World's First Lagoon Power Plants Unveiled In UK

Yes, but around Swansea, and in the Bristol Channel, the tidal range is around 4-5m -- that's the second highest tidal range in the world. The channel is around over a km across and many km long. That's an awful lot of water. If a barrier were placed across the channel, it would produce something like 25% of the energy requirements of the UK. Even these lagoons are likely to produce a significant percentage of demand. Pretty significant as far as I can see.

Of course, this may not be so significant on a global basis, but really all that this is saying is that renewables are multi-modal, so no form is going to be dominant in the way coal, oil and gas are. In the UK, we have lots of wind, and lots of coast with big tides. But we are never going to rival Germany for solar power, and it's nothing to do with German engineering.

Comment: Re:... Driverless cars? (Score 3, Interesting) 301

As the article points out, this is not a big cost for the companies involved. Unionisation of the buses is not going to make the slightest bit of difference whatsoever to Google's desire to generate a self-driving vehicle. The market is enormous, so they have all the incentive in the world.

What is going to make a difference to these companies is some degree of collective action. We know that many SV companies have been involved in collection action in the past, with non-compete agreements to keep wages of high-skilled workers low. It is a good thing if the shoe is on the other foot for a while. The only real sad thing is that this is unlikely to spread to where it is really needed -- in the third world sweat shop supply chains.

Comment: Re:i always thought this was a good idea (Score 1) 245

by Phillip2 (#49135203) Attached to: The Peculiar Economics of Developing New Antibiotics

Nice idea, I suppose, but unfortunately working out whether you really have come up with the goods is complex. Nor is it something that happens all at once; you have many stages of clinical trials, and even after release drugs can get pulled at a later date when we discover that they are not so effective.

So, in practice, there would still be a whole lot of annual reports on how well you're progressing anyway. It's basically the same thing.

Comment: Re:A functional programmer (Score 1) 252

by Phillip2 (#49015917) Attached to: AP Test's Recursion Examples: An Exercise In Awkwardness

TRO I would guess stands for Tail Recursion Optimisation, which is a special case of the Tail Call Optimisation. It is always possible to drop state for the stack after a tail call, even if it not recursive. This allows, for example, implementing mutually recursive functions without blowing up the stack.

Both Scala and Clojure only implement the self-recursive TCO. In general, they both try to compile into Java in a naturalistic way -- so a function call in either compiles to a byte code method call. The JVM is Turing complete, so they could implement anything that they want, but they'd have to loose the close relationship between their language and the JVM. So, they only do this for the tail recursion call. This gets 90% of the benefit for the least effort.

Comment: Re:A functional programmer (Score 1) 252

by Phillip2 (#49013243) Attached to: AP Test's Recursion Examples: An Exercise In Awkwardness

That TCO is implemented by both Scala and Clojure sort of demonstrates the point really. I mean, why would they bother if the Java Compiler did it already?

In fact, both Scala and Clojure implement it in the same way -- they remove the function (method) recursive call. In otherwords, you see a recursive call in Clojure/Scala but there is not one in the byte code. Method calls in Java consume stack. Try the answer that I gave you earlier. Otherwise, can you please show me the part of the JVM spec which describes TCO on the JVM. It has to be there, because TCO changes the way that you program.

There is a nice write-up on Java and how it does not implement TCO here at DrDobbs.

http://www.drdobbs.com/jvm/tai...

Comment: Re:A functional programmer (Score 1) 252

by Phillip2 (#49012527) Attached to: AP Test's Recursion Examples: An Exercise In Awkwardness

Nope. It's just not there. I think you mean JVM, anyway, rather than "java language implementation" which is rather ambiguous.

It's not a surprise. Java was never functional. Why have an optimisation which essentially rewrites recursion as a form of iteration, when the programmer is going to use iteration anyway?

This is changing now, I think, that the JVM is becoming more important than Java.

Money can't buy love, but it improves your bargaining position. -- Christopher Marlowe

Working...