[R] choose() function returning anomalous results (zero instead of one)

[David Winsemius]

On Sep 6, 2012, at 2:45 PM, Shayne Hodge wrote:

> I accidentally posted the wrong version of my code, omitting the Q1 loop,
> and, sure enough that loop generates non-integers:
> 
> qfracseq <- seq(from = 1, to = 0, by = -.1)
> Q <- 10
> Qseq <- Q*qfracseq
> 
>> Qseq [1] 10.00000000000000000  9.00000000000000000  8.00000000000000000  7.00000000000000000
> [5]  6.00000000000000000  5.00000000000000000  3.99999999999999911
> 2.99999999999999911
> [9]  1.99999999999999956  0.99999999999999978  0.00000000000000000
> 
> 
> -----
> 
> I'm a tad puzzled by why my code would do this; is this a result of some
> base-10 fractions not representing as cleanly in base-2 as in -10?


Read the FAQ. ("Why doesn't R think these numbers are equal?")  Can't remember for sure but suspect someplace around 7.31


snipped
-- 
David Winsemius, MD
Alameda, CA, USA