Timeline for Sieve of Eratosthenes JavaScript implementation - performance very slow over a certain number
Current License: CC BY-SA 3.0
20 events
| when toggle format | what | by | license | comment | |
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| Feb 11, 2015 at 23:45 | history | edited | 200_success |
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| Feb 11, 2015 at 16:39 | comment | added | Nick Udell | @JamieC "Thanks for the answers, however I'm not asking how this can be improved." - Welcome to CodeReview! All code here is fair game for reviewers, and all topics too. I hope you have a good time here, and get some useful feedback! | |
| Feb 11, 2015 at 15:23 | comment | added | Pointy | Right, and that's not what Mr. Erathosthenes proposed. | |
| Feb 11, 2015 at 15:22 | comment | added | JamieC | It pushes all odd numbers into an array, not a list of primes. The function then goes through the array and removes multiples of each prime. Then finally returns the modified list, which is a list of primes. | |
| Feb 11, 2015 at 15:21 | comment | added | Pointy | OK, then the simple answer to your question is that your code is doing far more work than it should in order to implement the algorithm properly. | |
| Feb 11, 2015 at 15:17 | comment | added | JamieC | Yes, it returns exactly the same as your code for below 100. | |
| Feb 11, 2015 at 15:12 | comment | added | Pointy | Have you checked to see whether the value that your function returns is actually a list of prime numbers? | |
| Feb 11, 2015 at 15:11 | comment | added | Pointy | Your code pushes all odd numbers onto the list of primes. Not all odd numbers are prime numbers. | |
| Feb 11, 2015 at 15:08 | answer | added | Pointy | timeline score: 6 | |
| Feb 11, 2015 at 15:04 | comment | added | Esailija | If that's your main question you should ask a completely new question "Why is splicing an array so much slower for bigger arrays? in the V8 tag. And remove all redundancy about primes, it should just be about splice. | |
| Feb 11, 2015 at 15:02 | comment | added | JamieC | That doesn't explain how it's not a sieve of Erathosthenes. | |
| Feb 11, 2015 at 15:01 | comment | added | JamieC | Thanks for the answers, however I'm not asking how this can be improved. I know it's not perfect, but I'm using this as a way to teach myself. My main question was why it should take so much longer when increasing the input number by only 1. Has anyone encountered this before? Do you have similar results if you run the code? | |
| Feb 11, 2015 at 14:55 | comment | added | Matt Burland | See Sieve of Eratosthenes | |
| Feb 11, 2015 at 14:55 | comment | added | JamieC | @Pointy why isn't it? It's slightly modified, e.g. I don't bother pushing even numbers into the Array, but the essence of it is the same. | |
| Feb 11, 2015 at 14:50 | answer | added | ratchet freak | timeline score: 3 | |
| Feb 11, 2015 at 14:45 | comment | added | Esailija | Calling splice deep inside nested loops... ouch | |
| Feb 11, 2015 at 14:45 | comment | added | Matt Burland | Here's a jsperf to compare. | |
| Feb 11, 2015 at 14:43 | comment | added | Pointy | That's not a Sieve of Erathosthenes implementation. | |
| Feb 11, 2015 at 14:39 | history | migrated | from stackoverflow.com (revisions) | ||
| Feb 11, 2015 at 14:38 | history | asked | JamieC | CC BY-SA 3.0 |