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On Melissa O’Neill’s PCG random number generator

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Re: On Melissa O’Neill’s PCG random number generator

#51

Post by greggyb »

mathperson wrote: post #45
the_stc wrote: post #43

Earlier quoted context omitted.

No. I am saying that giving the definition of a set each time is just extra verbosity. The whole paper had that extra verbiage, everywhere. Kind of why-use-one-word-when-ten-will-do feeling.

Could you share the paper? I mean if they were making a mathematical argument...it is kind of hard to do that without defining things..

"Consider the set P {p1, p2, ... pN} representing providers and the set c {c1, c2, ... cN} representing customers"

versus

"Consider the set P of providers and the set C of customers"

The former is about 2x the length of the latter. This is the verbosity I read into the original comment.

Re: On Melissa O’Neill’s PCG random number generator

#52

Post by sulizilxia »

I love O'Neill's work on PCG, and loved the talks by her I watched online.

As a tenured professor I want to say two things about this piece:

1. I think academic publishing will be forced to change. I'm not sure what it's going to look like in the end, but traditional journals are starting to seem really quaint and outdated now.

2. As far as I can tell from what she's written on the PCG page, the submission to TOMS is a poor example, because no one I know expects to be done with one submission. That is, no one I know submits a paper to one journal, even one reputable journal, and is done. They submit and it gets rejected and revise it and resubmit it, maybe three or even four times. After the fourth or fifth time, you might give up, but not necessarily even then.

I have mixed feelings about the PCG paper as an example, because in some ways it's great: an example of how something very influential has superceded traditional academic publishing. In other ways, though, it's horrible, because it's misleading about the typical academic publishing experience. Yes, academic publishing is full of random nonsense, and corruption, but yes, you can also get past it (usually) with just a little persistence. In still other ways, it's a good example of what we might see increasingly, which is a researcher having a lower threshold for the typical bullshit out there.

Re: On Melissa O’Neill’s PCG random number generator

#53

Post by mathperson »

greggyb wrote: post #51
mathperson wrote: post #45

Earlier quoted context omitted.

Could you share the paper? I mean if they were making a mathematical argument...it is kind of hard to do that without defining things..

"Consider the set P {p1, p2, ... pN} representing providers and the set c {c1, c2, ... cN} representing customers" versus "Consider the set P of providers and the set C of customers" The former is about 2x the length of the latter. This is the verbosity I read into the original comment.

mmm I see.

Re: On Melissa O’Neill’s PCG random number generator

#54

Post by thanatropism »

mathperson wrote: post #48
thanatropism wrote: post #36

Earlier quoted context omitted.

There's room for accessible and for abstruse literature. Usually what happens with novel work is that initial publications are abstruse but met with excitement by the scholarly community and gradually more accessible works (as the number of collaborators/coauthors grows too) are published. That said, even if multi-culti math means that top-line researchers are going to be spending time with song-and-dance introductio…

What is multi-culti?

It's a common sarcastic term hurled at things like "inclusive CS".

For all I know this iteration of "inclusive" could be the Right Stuff -- proper intellectual discipline even as it advances secondary goals of "inclusiveness". But stiiill... she should have by now had the common courtesy of producing a short document aimed at experts, possibly prepared by her underlings. This would also have helped the career of the underlings.

Re: On Melissa O’Neill’s PCG random number generator

#55

Post by PhasmaFelis »

lfowles wrote: post #29
kurthr wrote: post #28

Earlier quoted context omitted.

Hmmm... is HN removing ^carets? Replace 247 with '2^47', Which is ~'1.28x10^14' or ~36 hours in ns.

Hah. I used double asterisks, should have seen that coming in hindsight. Muphry's Law.

I've often been frustrated trying to put more than one asterisk (not italic tag) in an HN comment.

Serious question, what happened to WYSIWYG? The Web has supported it for like 20 years, why have we standardized on clunky in-line markup for rich text entry, pretty much everywhere?

Re: On Melissa O’Neill’s PCG random number generator

#56

Post by Houshalter »

I once tried to develop my own fast random number generate using nothing but bitwise operations. On the theory they were the fastest/simplest. I had a program generate thousands of random combinations of bitwise functions. And then used statistical tests to see which ones produced the most "random" seeming behavior.

It worked as far as I can tell. But I don't trust the statistical tests. Who is to say there isn't a very obvious pattern in the numbers that I didn't test for or notice? How do you prove a random number generator is good?

Re: On Melissa O’Neill’s PCG random number generator

#57

Post by fwdpropaganda »

eridius wrote: post #49
fwdpropaganda wrote: post #25

Physicist here. Off-topic > And it is not even entirely clear what “really random” would mean. It is not clear that we live in a randomized universe… At the quantum level it really is clear that we live in a really random universe. What's the meaning of really random? The outcome of a quantum process. On-topic. Yeah, you have to know your audience. As OP mentions, just because the paper wasn't published doesn't preve…

A quantum process is a random process, but isn't it still an open philosophical question as to whether the "random process" we observe is truly random, or is instead governed by deterministic hidden state?

No, all theories of (local) hidden variables have been experimentally ruled out.

https://en.wikipedia.org/wiki/Bell%27s_theorem

> Bell's theorem states that any physical theory that incorporates local realism cannot reproduce all the predictions of quantum mechanical theory. Because numerous experiments agree with the predictions of quantum mechanical theory, and show differences between correlations that could not be explained by local hidden variables, the experimental results have been taken by many as refuting the concept of local realism as an explanation of the physical phenomena under test. For a hidden variable theory, if Bell's conditions are correct, the results that agree with quantum mechanical theory appear to indicate superluminal effects, in contradiction to the principle of locality.

Re: On Melissa O’Neill’s PCG random number generator

#58

Post by thaumasiotes »

Houshalter wrote: post #56

I once tried to develop my own fast random number generate using nothing but bitwise operations. On the theory they were the fastest/simplest. I had a program generate thousands of random combinations of bitwise functions. And then used statistical tests to see which ones produced the most "random" seeming behavior. It worked as far as I can tell. But I don't trust the statistical tests. Who is to say there isn't a v…

> How do you prove a random number generator is good?

You can't; that's the nature of randomness. You can prove they're bad, though.

Re: On Melissa O’Neill’s PCG random number generator

#59

Post by thaumasiotes »

mathperson wrote: post #48
thanatropism wrote: post #36

Earlier quoted context omitted.

There's room for accessible and for abstruse literature. Usually what happens with novel work is that initial publications are abstruse but met with excitement by the scholarly community and gradually more accessible works (as the number of collaborators/coauthors grows too) are published. That said, even if multi-culti math means that top-line researchers are going to be spending time with song-and-dance introductio…

What is multi-culti?

"Multicultural"

Re: On Melissa O’Neill’s PCG random number generator

#60

Post by thaumasiotes »

greggyb wrote: post #51
mathperson wrote: post #45

Earlier quoted context omitted.

Could you share the paper? I mean if they were making a mathematical argument...it is kind of hard to do that without defining things..

"Consider the set P {p1, p2, ... pN} representing providers and the set c {c1, c2, ... cN} representing customers" versus "Consider the set P of providers and the set C of customers" The former is about 2x the length of the latter. This is the verbosity I read into the original comment.

The first is required when you want to later refer to an individual element from the set.

"Consider the set P of providers" means when you eventually refer to p_2, you'll have to note that you mean an element (the second, in some sense) of P. That moved the verbosity around rather than eliminating it.

To me it seems like a much bigger error that "Consider the set P {p_1, p_2, ... p_N} representing providers and the set c {c_1, c_2, ... c_N} representing customers" states outright that the sets are equal in size. I would expect C to be much larger than P.

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