File talk:Sieve of Eratosthenes animation.gif
Previous discussion
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Discussed at en:Talk:Sieve_of_Eratosthenes#Image. The original version by Brian0918 is preferred for the Sieve of Eratosthenes. The changed version by 6Sixx does not reflect properly the sieve of Eratosthenes, but rather that of Euler. It should not be used therefore, as an illustration of the sieve of Eratosthenes. Going to revert back. WillNess (talk) 16:19, 22 November 2011 (UTC)
- As JohnBlackburne writes there:
- "In fact that was the version promoted to featured picture, before being changed without discussion of any sort. Given that and the disagreements the current version has generated I've been bold and reverted it."
- WillNess (talk) 16:51, 22 November 2011 (UTC)
Missing numbers?
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Why are most of the 7s not included? Why are some of the 5s not included? Travürsa (talk) 07:53, 13 February 2012 (UTC)
- My guess is simple overlook. FWIW, this other version has been fixed for consistency. --Waldir talk 00:40, 14 February 2012 (UTC)
- It is explained at w:Sieve of Eratosthenes. It's a simple optimisation to start from p2 for each prime p, as every composite less than p2 is found by previous stages of the sieve.--JohnBlackburne (talk) 01:24, 14 February 2012 (UTC)
- Oh, so that's the reason! Now it makes sense, thanks :) I've reverted my previous "fix" to the other image. Maybe this should be mentioned in the image description page? I also didn't get initially why some values were missing... --Waldir talk 20:21, 14 February 2012 (UTC)
- I've added a brief summary of the algorithm here, with perhaps more usefully a link to the en WP page where it's explained in much more detail.--JohnBlackburne (talk) 04:24, 16 February 2012 (UTC)
- Your summary is great, thank you :) --Waldir talk 10:40, 16 February 2012 (UTC)
- I've added a brief summary of the algorithm here, with perhaps more usefully a link to the en WP page where it's explained in much more detail.--JohnBlackburne (talk) 04:24, 16 February 2012 (UTC)
- Oh, so that's the reason! Now it makes sense, thanks :) I've reverted my previous "fix" to the other image. Maybe this should be mentioned in the image description page? I also didn't get initially why some values were missing... --Waldir talk 20:21, 14 February 2012 (UTC)
- It is explained at w:Sieve of Eratosthenes. It's a simple optimisation to start from p2 for each prime p, as every composite less than p2 is found by previous stages of the sieve.--JohnBlackburne (talk) 01:24, 14 February 2012 (UTC)
Error in this display
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In the final display the prime numbers are shown in magenta. The problem is that the first 4 primes: 2, 3, 5, & 7 are not shown in magenta, and they should be. I am not able to make this correction, as I am not a gif programmer. My website designer would like to use this gif as an illustration, with attribution of course. But I am against this unless a corrected version of the display is provided.
