[R] BUG: choose function

Duncan Murdoch murdoch at stats.uwo.ca
Fri Nov 23 02:31:00 CET 2007

On 22/11/2007 8:04 PM, Luis Salasar wrote:
> Hi,
>   I have used the function choose(n, k) sometimes, and i realized that it doesn't work properly for n < 0. For example, if one tries choose(-1, 3), it should be returned the value (-1)^3 = -1, since choose (-1, 3) = (-1)*(-2)*(-3)/3! = (-1)^3, but indeed R returns the value 0. I am using R version 2.5.1, it don't know if this little bug has already been solved in the new version. Thanks,

You're right.  There's some code to optimize the k <= 30 case and it 
doesn't take n < 0 into account.  I'll fix it.

Duncan Murdoch

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