Beefy Boxes and Bandwidth Generously Provided by pair Networks
Don't ask to ask, just ask

comment on

( #3333=superdoc: print w/replies, xml ) Need Help??
I know that this is a very old thread, but I just ran across it today while researching Sieve of Eratosthenes implementations. I am awed by the great programming, but much of it is beyond me. However, my main interest was to find a great SoE implementation for use and examples to others. I was really interested in outright performance. With this qualifier in mind, here are a few observations:

The fastest implementation was the c code by AnonymousMonk. However, it isn't perl and has memory limitations for finding larger primes. But it is blazing fast for small lists of primes - 1st two million primes found in less than 1 second.

The fastest perl implementation was the code by tilly. It found all primes up to 2,000,003 in 1 second. It also scaled nearly linearly for up to 32 million primes (the last one I tested). Wow!

The original code by thinker was good. It found all primes up to 2,000,003 in 10 seconds. It didn't scale as well for larger values of primes.

The code by merlynn has some kind of problem. It took it 43 seconds to find all primes up to 2,000,003 and didn't scale well at all for larger values.

Hope my "years late" comment doesn't upset anyone's apple cart. But if anyone else, like me, runs across this thread, it may offer something useful.

If I need to find a bunch of primes quickly, I would use tilly's code!


In reply to Re: Sieve of Eratosthenes with closures by djWestTexas
in thread Sieve of Eratosthenes with closures by thinker

Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":

  • Are you posting in the right place? Check out Where do I post X? to know for sure.
  • Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
    <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>
  • Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
  • Want more info? How to link or or How to display code and escape characters are good places to start.
Log In?

What's my password?
Create A New User
Domain Nodelet?
and the web crawler heard nothing...

How do I use this? | Other CB clients
Other Users?
Others imbibing at the Monastery: (3)
As of 2022-07-05 04:15 GMT
Find Nodes?
    Voting Booth?

    No recent polls found