How to generate quality random numbers in bulk?

Read more about it here:

https://developer.apple.com/library/mac/#documentation/Darwin/Reference/ManPages/man4/random.4.html

 

Command line:

Code:

apropos random

Command line:

Code:

man 4 random

Try a for loop.

How do you know a for loop isn't fast and efficient? If you have evidence, please post it. If you don't have evidence, then do the simplest thing that could possibly work (a for loop), then measure it.

The representation of the value in the array will affect speed. uint_32_t times may differ from uint_8_t, float, double, etc.

 

Check out this article.

http://domino.research.ibm.com/tchj...6547004d47e1/87a0c1cc3288480485256bfa0067f9a8

These guys managed 40 million pseudo-random numbers per second in 2002.

 

You specifically mentioned arc4random_uniform() in your first post. My conclusion is that you wanted random numbers uniformly distributed below a specific upper limit.

If you just wanted random bytes (i.e. uniformly distributed values in the range [0-255]), then you should have asked for that. The obvious answer would then be /dev/random, whose characteristics are described in the man page:

Code:

man 4 random

Or you could google the source for arc4random_buf(), which you could then use without needing to rely on 10.7.

 

If you have control over the platform and the CPU is new enough, use C's asm function to access Intel's built in random number generator. They've been in Macs for the past 2-3 years but I don't think the compilers utilize the features of the chips yet.

Based on the usage of the phrase "pseudo random" from that link, I suspect my suggestion is superior when it comes to how random the results are (you can look up Intel's papers on how the chips guarantee their own randomness) - but of course, if you're looking to support older devices it may not be feasible.