[R] vector indexing

[Rui Barradas]

Hello,

Try the following.

y=c(2,3,5,2,4,6,8,3,6,2,5)

first <- function(x) min(which(x))
prefix <- function(x, v) x[seq_len(v)]
suffix <- function(x, v) x[-seq_len(v)]

first(y > 4)
prefix(y, first(y > 4))
suffix(y, first(y > 4))


Hope this helps,

Rui Barradas
Em 23-10-2012 10:21, Al Ehan escreveu:
> Hi,
>
> I got a small problem on how to define the vector index without manually
> inspect the vector.
>
> example:
>
> y=c(2,3,5,2,4,6,8,3,6,2,5) #I have ten set of this kind of vectors (with
> different values but same length) that I would also like to run the routine
> below
>
> #say;
> v=the first index in y where the value is larger than 4, in this case index
> 3, value 5
>
> #what I would like to do is take y[1:v] and run it to some function
> #hence I should also get y[(v+1),length(y)] and can run to other function
> as well..
>
> I know this is easy peasy for you..please help, many thanks.
>
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>
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