Re: [racket-dev] How about adding this simple list-shuffling procedure to racket?
I think we should put in a list shuffler into the core. Which should we use? The faster one? Jay On Thu, Nov 11, 2010 at 11:26 AM, Eli Barzilay e...@barzilay.org wrote: 5 minutes ago, Neil Toronto wrote: Carl Eastlund wrote: It's pick a random, uniform ordering, and then sort based on it. The random keys are chosen per element and cached (hence #:cache-keys? #t), not per comparison. Spanking good point, my good man. I think you're right. It's a very common method, and the classic example of the decorate-map-strip method that has some perl-guy's name slapped on it now. The wikipedia page on FY is pretty decent -- and one concern that I've encountered in the past is that it's sensitive to what that page calls modulo bias. The decorated version is more robust, especially with (random) that works at the highest `random' granularity. (BTW, to compare them you should use some (random 1000) thing to avoid the fp cost.) -- ((lambda (x) (x x)) (lambda (x) (x x))) Eli Barzilay: http://barzilay.org/ Maze is Life! _ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/dev -- Jay McCarthy j...@cs.byu.edu Assistant Professor / Brigham Young University http://faculty.cs.byu.edu/~jay The glory of God is Intelligence - DC 93 _ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/dev
Re: [racket-dev] How about adding this simple list-shuffling procedure to racket?
I think we want the one recommended by the statisticians. :) Robby On Fri, Nov 12, 2010 at 2:36 PM, Jay McCarthy jay.mccar...@gmail.com wrote: I think we should put in a list shuffler into the core. Which should we use? The faster one? Jay On Thu, Nov 11, 2010 at 11:26 AM, Eli Barzilay e...@barzilay.org wrote: 5 minutes ago, Neil Toronto wrote: Carl Eastlund wrote: It's pick a random, uniform ordering, and then sort based on it. The random keys are chosen per element and cached (hence #:cache-keys? #t), not per comparison. Spanking good point, my good man. I think you're right. It's a very common method, and the classic example of the decorate-map-strip method that has some perl-guy's name slapped on it now. The wikipedia page on FY is pretty decent -- and one concern that I've encountered in the past is that it's sensitive to what that page calls modulo bias. The decorated version is more robust, especially with (random) that works at the highest `random' granularity. (BTW, to compare them you should use some (random 1000) thing to avoid the fp cost.) -- ((lambda (x) (x x)) (lambda (x) (x x))) Eli Barzilay: http://barzilay.org/ Maze is Life! _ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/dev -- Jay McCarthy j...@cs.byu.edu Assistant Professor / Brigham Young University http://faculty.cs.byu.edu/~jay The glory of God is Intelligence - DC 93 _ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/dev _ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/dev
Re: [racket-dev] How about adding this simple list-shuffling procedure to racket?
Any objections to `shuffle' in `racket/list'? -- ((lambda (x) (x x)) (lambda (x) (x x))) Eli Barzilay: http://barzilay.org/ Maze is Life! _ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/dev
Re: [racket-dev] How about adding this simple list-shuffling procedure to racket?
Not by me. On Fri, Nov 12, 2010 at 2:25 PM, Eli Barzilay e...@barzilay.org wrote: Any objections to `shuffle' in `racket/list'? -- ((lambda (x) (x x)) (lambda (x) (x x))) Eli Barzilay: http://barzilay.org/ Maze is Life! _ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/dev -- Jay McCarthy j...@cs.byu.edu Assistant Professor / Brigham Young University http://faculty.cs.byu.edu/~jay The glory of God is Intelligence - DC 93 _ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/dev
