1 Apr 17:33 2007

## Re: [PEPr] Comment on Math::Math_Combinatorics

Jesus M. Castagnetto <jcastagnetto <at> yahoo.com>

2007-04-01 15:33:33 GMT

2007-04-01 15:33:33 GMT

Just as a reference. For combinations and permutations there exist some other variations, for example the "Complete Permutation" (or Derangement), and such other weirdness. See: http://mathworld.wolfram.com/Permutation.html http://mathworld.wolfram.com/Derangement.html http://mathworld.wolfram.com/AlternatingPermutation.html http://mathworld.wolfram.com/CircularPermutation.html http://mathworld.wolfram.com/Combination.html http://mathworld.wolfram.com/BinomialCoefficient.html ... etc. Caveat: I had not looked in detail at your package. My net connection right now is quite flaky. Cheers. --- David Sanders <dsanders <at> baselinesolutions.com.au> wrote: > > I was thinking more of having repitition as an option. Wiki*said*the > definition can be either with or without repitition for both combinations > and permutations. (Now this is what I don't like about wiki: Someone has > deleted the "Permutations without Repitition" sub-section without even > providing a reason. See the history tab) > > > > > > However, there's a topic to think about - repetitions. The original > > definition of combination in mathematics implies that the elements have > > to be unique, i.e. the combinations of the set {A, A, B} are the same as > > these of {A, B}, of {A, A, A, A, B}, etc. Nevertheless, the term > > "combination with repetition" exists. I will try to take a look in my > > university courses on combinatorics during the weekend, because I'm > > uncertain what is the correct behaviour that has to be followed in the > > package. > > > > > -- > David Sanders > shangxiao > > -- > PEAR Development Mailing List (http://pear.php.net/) > To unsubscribe, visit: http://www.php.net/unsub.php > > -- Jesus M. Castagnetto (jcastagnetto <at> yahoo.com) Web site: http://www.castagnetto.org/ Research: http://metallo.scripps.edu/ PEAR stuff: http://pear.php.net/user/jmcastagnetto ____________________________________________________________________________________ Finding fabulous fares is fun. Let Yahoo! FareChase search your favorite travel sites to find flight and hotel bargains. http://farechase.yahoo.com/promo-generic-14795097 -- -- PEAR Development Mailing List (http://pear.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php