hi Orm,
this is from MathWorld:
Permutation: The rearrangement of elements in an ordered list S into a one-to-one correspondence with S itself, also called an "arrangement number" or "order." The number of permutations on a set of elements is given by n! (n factorial).
Combination: The number of ways of picking k _unordered_ outcomes from n possibilities. Also known as the binomial coefficient or choice number [...] For example [for n==4, k==2] there are 6 combinations on {1,2,3,4}, namely {1,2}, {1,3}, {1,4}, {2,3}, {2,4}, and {3,4}.
yKzzsofrt
Orm Finnendahl wrote:
hi Krzyzstof,
...
Hi Krzysztof,
you're absolutely right. Blame on me. Permutations are distinct from combinations in being ordered and having the same number of elements (in difference to variations being ordered subsets). That's what happens if you want to be smart... In my mail it should say "the period of one permutation, continously reapplied to itself...".
BTW, my mail somehow got mixed up with a former one, I wrote before I had a glance at the code. The external I was talking about, maps index numbers (ranging from 0 to ((n factorial) -1)), received as integer in the inlet, into a one-to-one correspondance to all possible permutations. With this permutation set, any list received in the inlet got reordered according to it.
I don't remember, how I did the algorithm, which directly calculates a permutation from an integer. I remember finding it quite challenging. But go have a look :-)
Yours, Orm
Am Freitag, den 25. Januar 2002 um 14:43:38 Uhr (+0100) schrieb Krzysztof Czaja:
hi Orm,
this is from MathWorld:
Permutation: The rearrangement of elements in an ordered list S into a one-to-one correspondence with S itself, also called an "arrangement number" or "order." The number of permutations on a set of elements is given by n! (n factorial).
Combination: The number of ways of picking k _unordered_ outcomes from n possibilities. Also known as the binomial coefficient or choice number [...] For example [for n==4, k==2] there are 6 combinations on {1,2,3,4}, namely {1,2}, {1,3}, {1,4}, {2,3}, {2,4}, and {3,4}.
yKzzsofrt
Orm Finnendahl wrote:
hi Krzyzstof,
...