Coder's Revolution - Mathmatics

Generating Primes Revisited: My Modifications To The Sieve of Eratosthenes

Tue, 01 Feb 2011 03:28:00 -0500

In a recent pissing match between ColdFusion and PHP, Jared Rypka-Hauer was demonstrating the performance of a function that generated prime numbers. The discussion really wasn't about the BEST prime generator as much as it was about how much ColdFusion can kick PHP's puny butt all over town. Never the less, I piped up in the comments to ask Jared to compare a prime number generator that I wrote a while back based on the Sieve of Eratosthene. After Jared asked some good questions about how my code worked I figured it was time I stopped high-jacking the comments of the PHP pooper train. I decided to spin off a new post to highlight some significant performance gains I was able to produce. [More]

ColdFusion UDF: Calculate A Number's Divisors

Fri, 14 Aug 2009 23:24:00 -0500

Here's another UDF I was tinkering with last week. I wanted to be able to count all of the numbers that divided evenly into a given integer. I couldn't find a ColdFusion implementation, so after getting some advice from Stack Overflow I created my own. [More]

Calculate Prime Numbers: Sieve of Eratosthenes

Thu, 13 Aug 2009 23:34:00 -0500

Ahh... the quintessential math problem-- finding prime numbers. Last week while tinkering with a math challenge I needed to find all of the primes up to a given number. There was a version on cflib.org, but I thought I could do it in less code, so I dug in myself. [More]