[R] odd, even indices of a vector

[Richard M. Heiberger]

## these functions assume the argument is integer

odd <- function(x) x%%2 != 0

even <- function(x) x%%2 == 0

evenb <- function(x) !odd(x)

odd(1:10)
even(1:10)
evenb(1:10)

On Mon, Jul 21, 2014 at 4:33 PM, carol white <wht_crl at yahoo.com> wrote:
> Might be a trivial question but how to identify the odd and even indices of a vector?
>
> x = c(1,z,w,2,6,7)
>
> el of odd indices= 1,w,6
> el of even indices= z,2,7
>
> given the def of odd and even in https://stat.ethz.ch/pipermail/r-help/2010-July/244299.html
>
> should a loop be used?
>
> for (i in 1: length(x))
> if (is.odd(i)) print (i)
>
>
> Carol
>
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>
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