R help - Apr 2007 - Subsetting list of vectors with list of (boolean) vectors?

Dear Rologists,

I'm stuck with this. How would you do this efficiently:
> aPGI
[[1]]
[1] "864"  "5576"

> aPGItest
[[1]]
[1]  TRUE FALSE
> result <- [magic box involving subset)
> result
[[1]]
[1] "864"

Thanks for any hints,

Joh

On Thu, 2007-04-12 at 18:12 +0200, Johannes Graumann
wrote:
> Dear Rologists,
> 
> I'm stuck with this. How would you do this efficiently:
> 
> > aPGI
> [[1]]
> [1] "864"  "5576"
> 
> 
> > aPGItest
> [[1]]
> [1]  TRUE FALSE
> 
> > result <- [magic box involving subset)
> 
> > result
> [[1]]
> [1] "864"
> 
> Thanks for any hints,
> 
> Joh
> lapply(seq(along = length(aPGI)), function(x) aPGI[[x]][aPGItest[[x]]])
[[1]]
[1] "864"


I think that this should be a generic solution for multiple (but common) levels
in each list.

HTH,

Marc Schwartz

Johannes Graumann <johannes_graumann at web.de> writes:
> Dear Rologists,
>
> I'm stuck with this. How would you do this efficiently:
>
>> aPGI
> [[1]]
> [1] "864"  "5576"
>
>
>> aPGItest
> [[1]]
> [1]  TRUE FALSE
>
>> result <- [magic box involving subset)
result <- aPGI[aPGItest[[1]]]
>> result
> [[1]]
> [1] "864"
>
+ seth

-- 
Seth Falcon | Computational Biology | Fred Hutchinson Cancer Research Center
http://bioconductor.org