Roger Hui wrote: >> I basically agree with this point. On these grounds, ! is the wrong >> way round: you are more likely to calculate x ! y for fixed y than >> fixed x. > > What are some examples of fixing an argument of ! ? The only non-trivial > one I am aware of is > 2&! = +/@i. >
I was thinking of calculations with binomial coefficients, for example in probability theory, where you are likely to want to add some function of nCr for fixed n. For example, if you toss 10 coins, the probability of getting 8, 9 or 10 heads is +/ (8 9 10 ! 10)%2^10 0.0546875 If you had several such calculations, you would be inclined to fix y. Of course, this is taken care of by rank. I am just saying that 8 9 10 ! 10 is more likely than 3 ! 7 8 9. I am not convinced one is more natural, however. Best wishes, John ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
