Comments on: Sorting Used in Anger http://www.win-vector.com/blog/2008/04/sorting-in-anger/?utm_source=rss&utm_medium=rss&utm_campaign=sorting-in-anger The Applied Theorist's Point of View Thu, 15 Jul 2010 00:13:50 +0000 hourly 1 http://wordpress.org/?v=3.0.1 By: jmount http://www.win-vector.com/blog/2008/04/sorting-in-anger/comment-page-1/#comment-1883 jmount Wed, 17 Feb 2010 01:12:20 +0000 http://www.win-vector.com/blog/?p=13#comment-1883 This sort of problem with sorting seems like it has always been with us. For example: Bentley quoting Knuth: "in section 6.2.1 of his 'Sorting and Searching,' Knuth points out while the first binary search was published in 1946, the first published binary search without bugs did not appear until 1962" (Programming Pearls 2nd edition, "Writing Correct Programs", section 4.1, p. 34). See also: Nearly All Binary Searches and Mergesorts are Broken (2006) http://googleresearch.blogspot.com/2006/06/extra-extra-read-all-about-it-nearly.html This sort of problem with sorting seems like it has always been with us. For example: Bentley quoting Knuth: “in section 6.2.1 of his ‘Sorting and Searching,’ Knuth points out while the first binary search was published in 1946, the first published binary search without bugs did not appear until 1962″ (Programming Pearls 2nd edition, “Writing Correct Programs”, section 4.1, p. 34).

See also: Nearly All Binary Searches and Mergesorts are Broken (2006) http://googleresearch.blogspot.com/2006/06/extra-extra-read-all-about-it-nearly.html

]]> By: admin http://www.win-vector.com/blog/2008/04/sorting-in-anger/comment-page-1/#comment-8 admin Wed, 13 May 2009 22:10:43 +0000 http://www.win-vector.com/blog/?p=13#comment-8 Finally got around to going through Bentley's masterpiece Programming Pearls Second Edition. The tone is definitely different than that in Beautiful Code Bentley calls out bad performance and bugs much earlier (and expresses an aversion to reading others bug-filled "corrections"). Column 11 of Programing Pearls presents 4 quick sorts, all of which use a single split point (but some smarts to avoid the quadratic run time on constant data). Finally got around to going through Bentley’s masterpiece Programming Pearls Second Edition. The tone is definitely different than that in Beautiful Code Bentley calls out bad performance and bugs much earlier (and expresses an aversion to reading others bug-filled “corrections”). Column 11 of Programing Pearls presents 4 quick sorts, all of which use a single split point (but some smarts to avoid the quadratic run time on constant data).

]]> By: admin http://www.win-vector.com/blog/2008/04/sorting-in-anger/comment-page-1/#comment-4 admin Sat, 14 Jun 2008 18:35:54 +0000 http://www.win-vector.com/blog/?p=13#comment-4 I found out that Tim Peters (of PythonLabs) wrote a very nice article covering these kind of issues with QuickSort in his introduction for chapter 5 of the Python Cookbook (2nd Edition, O'Reilly 2005). Hoare's original implementation (as a junior programmer) won a bet that he could not come up with anything faster than the highly tuned system sorting function (a great example of "coding in the small"). Of course in the wild a lot of other issues show up (minimizing object creation, applying permutations to external lists, non-deterministic floating point implementations, heap structures and stable sorting). I found out that Tim Peters (of PythonLabs) wrote a very nice article covering these kind of issues with QuickSort in his introduction for chapter 5 of the Python Cookbook (2nd Edition, O’Reilly 2005). Hoare’s original implementation (as a junior programmer) won a bet that he could not come up with anything faster than the highly tuned system sorting function (a great example of “coding in the small”). Of course in the wild a lot of other issues show up (minimizing object creation, applying permutations to external lists, non-deterministic floating point implementations, heap structures and stable sorting).

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