Comments on: Finding primes with Erlang and Clojure http://bigdingus.com/2008/07/01/finding-primes-with-erlang-and-clojure/ A lot of the time I hear ducks Sun, 05 Feb 2012 01:47:23 +0000 http://wordpress.org/?v=2.2.1 By: e http://bigdingus.com/2008/07/01/finding-primes-with-erlang-and-clojure/#comment-4792 e Wed, 13 May 2009 10:54:31 +0000 http://bigdingus.com/2008/07/01/finding-primes-with-erlang-and-clojure/#comment-4792 would this functional heap have been useful? http://code.google.com/p/jc-pheap/ would this functional heap have been useful? http://code.google.com/p/jc-pheap/

]]> By: Cybil http://bigdingus.com/2008/07/01/finding-primes-with-erlang-and-clojure/#comment-3801 Cybil Tue, 10 Feb 2009 12:35:31 +0000 http://bigdingus.com/2008/07/01/finding-primes-with-erlang-and-clojure/#comment-3801 > since prime numbers are pretty uniformly distributed along the natural number line Terribly wrong. The prime density decreases towards infinity. The asymptotic propability of the number N to be prime is 1 / ln(N). See http://en.wikipedia.org/wiki/Prime_number_theorem for example. > since prime numbers are pretty uniformly distributed along the natural number line

Terribly wrong. The prime density decreases towards infinity. The asymptotic propability of the number N to be prime is 1 / ln(N). See http://en.wikipedia.org/wiki/Prime_number_theorem for example.

]]> By: The BigDingus Blogger http://bigdingus.com/2008/07/01/finding-primes-with-erlang-and-clojure/#comment-1194 The BigDingus Blogger Wed, 02 Jul 2008 19:54:20 +0000 http://bigdingus.com/2008/07/01/finding-primes-with-erlang-and-clojure/#comment-1194 Sorry about the blog software. I'm too lazy to deal with Wordpress myself, so this is just the default setup 1&1 provides. Anyway I think we do understand the sieve the same way. In fact your comment makes me realize that my multiplies are unnecessary, so I'll change them to adds. Sorry about the blog software. I’m too lazy to deal with Wordpress myself, so this is just the default setup 1&1 provides.

Anyway I think we do understand the sieve the same way. In fact your comment makes me realize that my multiplies are unnecessary, so I’ll change them to adds.

]]> By: qebab http://bigdingus.com/2008/07/01/finding-primes-with-erlang-and-clojure/#comment-1193 qebab Wed, 02 Jul 2008 18:23:10 +0000 http://bigdingus.com/2008/07/01/finding-primes-with-erlang-and-clojure/#comment-1193 Right, so I didn't think about this whole html thing, and your blog ate my code, and most of my post. I'll see if I can be bothered to write it up again, at some point. Right, so I didn’t think about this whole html thing, and your blog ate my code, and most of my post. I’ll see if I can be bothered to write it up again, at some point.

]]> By: qebab http://bigdingus.com/2008/07/01/finding-primes-with-erlang-and-clojure/#comment-1192 qebab Wed, 02 Jul 2008 18:21:30 +0000 http://bigdingus.com/2008/07/01/finding-primes-with-erlang-and-clojure/#comment-1192 The most trivial, but still efficient prime-sieve I know, is the sieve of Eratosthenes (indeed the one described in the paper). I am not familiar enough with Erlang (yet) to see if you have understood it the same way as have I, but I'll provide short python-style pseudocode for it: candidates = [2..lim] i = 0 while i This is a very computer-sciency algorithm, it is so easy to understand, and it uses nothing more complex than addition, really (except in the condition for the outer while-loop). I think it may be my favorite algorithm of all time. The most trivial, but still efficient prime-sieve I know, is the sieve of Eratosthenes (indeed the one described in the paper). I am not familiar enough with Erlang (yet) to see if you have understood it the same way as have I, but I’ll provide short python-style pseudocode for it:

candidates = [2..lim]
i = 0
while i

This is a very computer-sciency algorithm, it is so easy to understand, and it uses nothing more complex than addition, really (except in the condition for the outer while-loop). I think it may be my favorite algorithm of all time.

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