[R] vector indexing

[Ivan Calandra]

Hi,

Is it what you're looking for?

which(y>4)  ##all indexes for y>4
[1]  3  6  7  9 11
which(y>4)[1]  ##the first index
[1] 3

HTH,
Ivan

--
Ivan CALANDRA
Université de Bourgogne
UMR CNRS/uB 6282 Biogéosciences
6 Boulevard Gabriel
21000 Dijon, FRANCE
+33(0)3.80.39.63.06
ivan.calandra at u-bourgogne.fr
http://biogeosciences.u-bourgogne.fr/calandra

Le 23/10/12 11:21, Al Ehan a écrit :
> 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.
>
> 	[[alternative HTML version deleted]]
>
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