Dear list, I hope I can define my problem in an understandable manner. I seek some funktion that finds me the index of the value in a vector 1 that is the least bigger then the value in another vector 2. And this for all values in vector 2. For example: vector 1 : c(1,2,6) vector 2 : c(0,0.5,1,2,3,8) the result should be as long as vector 2 and give the indices of the corresponding elements in vector 1: result: c(1,1,2,3,3,NA) Any suggestions how to do this without doing complicated loops through vector 2? Cheers Jannis
On Dec 16, 2010, at 12:31 PM, Jannis wrote:> Dear list, > > > I hope I can define my problem in an understandable manner. I seek > some funktion that finds me the index of the value in a vector 1 > that is the least bigger then the value in another vector 2. And > this for all values in vector 2. > > For example: > > > vector 1 : c(1,2,6) > > vector 2 : c(0,0.5,1,2,3,8) > > > the result should be as long as vector 2 and give the indices of the > corresponding elements in vector 1: > > result: c(1,1,2,3,3,NA) > > Any suggestions how to do this without doing complicated loops > through vector 2??findInterval>-- David Winsemius, MD West Hartford, CT
Jannis -
One approach is as follows:
> one = c(1,2,6)
> two = c(0,0.5,1,2,3,8)
> findit = function(x,vec){
+ y = vec - x
+ y[y<=0] = NA
+ if(all(is.na(y)))NA else which.min(y)
+ }> > sapply(two,findit,one)
[1] 1 1 1 2 3 NA
- Phil Spector
Statistical Computing Facility
Department of Statistics
UC Berkeley
spector at stat.berkeley.edu
On Thu, 16 Dec 2010, Jannis wrote:
> Dear list,
>
>
> I hope I can define my problem in an understandable manner. I seek some
> funktion that finds me the index of the value in a vector 1 that is the
least
> bigger then the value in another vector 2. And this for all values in
vector
> 2.
>
> For example:
>
>
> vector 1 : c(1,2,6)
>
> vector 2 : c(0,0.5,1,2,3,8)
>
>
> the result should be as long as vector 2 and give the indices of the
> corresponding elements in vector 1:
>
> result: c(1,1,2,3,3,NA)
>
> Any suggestions how to do this without doing complicated loops through
vector
> 2?
>
>
> Cheers
> Jannis
>
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