4 ms·
I'm sorry for being unclear. The authors define a a PRNG as a sequence such that, if you find its distribution (histogram), it resembles the uniform distributi
by buo 13y ago
I'm sorry for being unclear.
The authors define a a PRNG as a sequence such that, if you find its distribution (histogram), it resembles the uniform distribution (all values appear the same number of times).
In 1,2,1,2,1,2,..., all values appear the same number of times and its histogram is uniform. However, it is not random. It is clearly not random -- so it is distinguishable from a uniform "true random" sequence, which was my point.
However, as was explained to me by another commenter, what I missed is that you may group a number of consecutive numbers together and find the histogram of that, and, in that case, my sequence fails to have a uniform histogram.
So, at this point I'm willing to accept that the author's definition is correct and I just had a hole in my understanding.
- bqe 13y agoAre you missing the point of a limit? As t->inf, if we counted all of the 1's and all of the 2's and all of the 3's, etc. and there were no 3's, it's not random according to this definition or any definition I'm aware of.
- pmelendez 13y agoI guess he is restricting the domain to [1,2] in which case 1,2,1,2,1,2... is as "random" as 1,2,2,2,1,2,1,1 ... I guess what is bothering him is the lack of entropy in the sequence.
- bmm6o 13y agoI guess I could see your interpretation, but it requires that you ignore all of the context of the paper. For instance, you take distribution to equal histogram. This may make sense in some contexts, but here it's absolutely not true; the values are supposed to be taken independently from some probability distribution. Pro tip: if you think you've spotted a major problem in the first line of an abstract, maybe give the author the benefit of the doubt. Especially if you're not familiar with the field.
- buo 13y agoI take your point, I should have phrased my thoughts differently. I did start with "I think", but I could have made it clearer that I didn't mean to criticize the paper, but rather to invite explanations from people who know the subject better than I do.
- bmm6o 13y agoYes, it's always interesting how different presentations of the same basic idea are received. "Is X false?" gets a much different response than "why is X true?". It's good to keep in mind that the second one tends to elicit more helpful replies.